51
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Hou W, Cortez P, Wuhrer R, Macartney S, Bozhilov KN, Liu R, Sheppard LR, Kisailus D. Oriented epitaxial TiO 2 nanowires for water splitting. NANOTECHNOLOGY 2017; 28:265602. [PMID: 28510531 DOI: 10.1088/1361-6528/aa7356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Highly oriented epitaxial rutile titanium dioxide (TiO2) nanowire arrays have been hydrothermally grown on polycrystalline TiO2 templates with their orientation dependent on the underlying TiO2 grain. Both the diameter and areal density of the nanowires were tuned by controlling the precursor concentration, and the template surface energy and roughness. Nanowire tip sharpness was influenced by precursor solubility and diffusivity. A new secondary ion mass spectrometer technique has been developed to install additional nucleation sites in single crystal TiO2 templates and the effect on nanowire growth was probed. Using the acquired TiO2 nanowire synthesis knowhow, an assortment of nanowire arrays were installed upon the surface of undoped TiO2 photo-electrodes and assessed for their photo-electrochemical water splitting performance. The key result obtained was that the presence of short and dispersed nanowire arrays significantly improved the photocurrent when the illumination intensity was increased from 100 to 200 mW cm-2. This is attributed to the alignment of the homoepitaxially grown nanowires to the [001] direction, which provides the fastest charge transport in TiO2 and an improved pathway for photo-holes to find water molecules and undertake oxidation. This result lays a foundation for achieving efficient water splitting under conditions of concentrated solar illumination.
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Affiliation(s)
- Wenting Hou
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States of America
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52
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Jang B, Hong A, Kang HE, Alcantara C, Charreyron S, Mushtaq F, Pellicer E, Büchel R, Sort J, Lee SS, Nelson BJ, Pané S. Multiwavelength Light-Responsive Au/B-TiO 2 Janus Micromotors. ACS NANO 2017; 11:6146-6154. [PMID: 28590716 DOI: 10.1021/acsnano.7b02177] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Conventional photocatalytic micromotors are limited to the use of specific wavelengths of light due to their narrow light absorption spectrum, which limits their effectiveness for applications in biomedicine and environmental remediation. We present a multiwavelength light-responsive Janus micromotor consisting of a black TiO2 microsphere asymmetrically coated with a thin Au layer. The black TiO2 microspheres exhibit absorption ranges between 300 and 800 nm. The Janus micromotors are propelled by light, both in H2O2 solutions and in pure H2O over a broad range of wavelengths including UV, blue, cyan, green, and red light. An analysis of the particles' motion shows that the motor speed decreases with increasing wavelength, which has not been previously realized. A significant increase in motor speed is observed when exploiting the entire visible light spectrum (>400 nm), suggesting a potential use of solar energy, which contains a great portion of visible light. Finally, stop-go motion is also demonstrated by controlling the visible light illumination, a necessary feature for the steerability of micro- and nanomachines.
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Affiliation(s)
- Bumjin Jang
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Ayoung Hong
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Ha Eun Kang
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Carlos Alcantara
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Samuel Charreyron
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Fajer Mushtaq
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Eva Pellicer
- Departament de Física, Universitat Autònoma de Barcelona , E-08193 Bellaterra, Spain
| | - Robert Büchel
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, CH-8092 Zürich, Switzerland
| | - Jordi Sort
- Departament de Física, Universitat Autònoma de Barcelona , E-08193 Bellaterra, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) , Pg. Lluís Companys 23, E-08010 Barcelona, Spain
| | | | - Bradley J Nelson
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
| | - Salvador Pané
- Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich , Zurich, CH-8092, Switzerland
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53
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Schopf SO, Hartwig A, Fritsching U, Mädler L. Imbibition into Highly Porous Layers of Aggregated Particles. Transp Porous Media 2017. [DOI: 10.1007/s11242-017-0876-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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54
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Hosseinpour S, Tang F, Wang F, Livingstone RA, Schlegel SJ, Ohto T, Bonn M, Nagata Y, Backus EHG. Chemisorbed and Physisorbed Water at the TiO 2/Water Interface. J Phys Chem Lett 2017; 8:2195-2199. [PMID: 28447795 PMCID: PMC5489252 DOI: 10.1021/acs.jpclett.7b00564] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The interfacial structure of water in contact with TiO2 is the key to understand the mechanism of photocatalytic water dissociation as well as photoinduced superhydrophilicity. We investigate the interfacial molecular structure of water at the surface of anatase TiO2, using phase-sensitive sum frequency generation spectroscopy together with spectra simulation using ab initio molecular dynamic trajectories. We identify two oppositely oriented, weakly and strongly hydrogen-bonded subensembles of O-H groups at the superhydrophilic UV irradiated TiO2 surface. The water molecules with weakly hydrogen-bonded O-H groups are chemisorbed, i.e. form hydroxyl groups, at the TiO2 surface with their hydrogen atoms pointing toward bulk water. The strongly hydrogen-bonded O-H groups interact with the oxygen atom of the chemisorbed water. Their hydrogen atoms point toward the TiO2. This strong interaction between physisorbed and chemisorbed water molecules causes superhydrophilicity.
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Affiliation(s)
- Saman Hosseinpour
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- E-mail:
| | - Fujie Tang
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- International
Center for Quantum Materials, Peking University, 5 Yiheyuan Road, Haidian, Beijing 100871, China
| | - Fenglong Wang
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Ruth A. Livingstone
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Simon J. Schlegel
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Tatsuhiko Ohto
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, 560-8531, Japan
| | - Mischa Bonn
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Yuki Nagata
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- E-mail:
| | - Ellen H. G. Backus
- Department
of Molecular Spectroscopy, Max Planck Institute
for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- E-mail:
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55
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Kwon G, Panchanathan D, Mahmoudi SR, Gondal MA, McKinley GH, Varanasi KK. Visible light guided manipulation of liquid wettability on photoresponsive surfaces. Nat Commun 2017; 8:14968. [PMID: 28440292 PMCID: PMC5413974 DOI: 10.1038/ncomms14968] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 02/17/2017] [Indexed: 12/11/2022] Open
Abstract
Photoresponsive titania surfaces are of great interest due to their unique wettability change upon ultraviolet light illumination. However, their applications are often limited either by the inability to respond to visible light or the need for special treatment to recover the original wettability. Sensitizing TiO2 surfaces with visible light-absorbing materials has been utilized in photovoltaic applications. Here we demonstrate that a dye-sensitized TiO2 surface can selectively change the wettability towards contacting liquids upon visible light illumination due to a photo-induced voltage across the liquid and the underlying surface. The photo-induced wettability change of our surfaces enables external manipulation of liquid droplet motion upon illumination. We show demulsification of surfactant-stabilized brine-in-oil emulsions via coalescence of brine droplets on our dye-sensitized TiO2 surface upon visible light illumination. We anticipate that our surfaces will have a wide range of applications including microfluidic devices with customizable wettability, solar-driven oil–water clean-up and demulsification technologies. Controlling surface wettability using visible light is highly attractive for a range of liquid separation technologies. Here, Varanasi, McKinley and colleagues fabricate dye-sensitized photocatalytic TiO2 surfaces on which liquid droplet motion can be externally manipulated by visible light illumination.
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Affiliation(s)
- Gibum Kwon
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Divya Panchanathan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Seyed Reza Mahmoudi
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Mohammed A Gondal
- Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 34464, Saudi Arabia
| | - Gareth H McKinley
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Kripa K Varanasi
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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56
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Wen G, Guo Z, Liu W. Biomimetic polymeric superhydrophobic surfaces and nanostructures: from fabrication to applications. NANOSCALE 2017; 9:3338-3366. [PMID: 28244533 DOI: 10.1039/c7nr00096k] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Numerous research studies have contributed to the development of mature superhydrophobic systems. The fabrication and applications of polymeric superhydrophobic surfaces have been discussed and these have attracted tremendous attention over the past few years due to their excellent properties. In general, roughness and chemical composition, the two most crucial factors with respect to surface wetting, provide the basic criteria for yielding polymeric superhydrophobic materials. Furthermore, with their unique properties and flexible configurations, polymers have been one of the most efficient materials for fabricating superhydrophobic materials. This review aims to summarize the most recent progress in polymeric superhydrophobic surfaces. Significantly, the fundamental theories for designing these materials will be presented, and the original methods will be introduced, followed by a summary of multifunctional superhydrophobic polymers and their applications. The principles of these methods can be divided into two categories: the first involves adding nanoparticles to a low surface energy polymer, and the other involves combining a low surface energy material with a textured surface, followed by chemical modification. Notably, surface-initiated radical polymerization is a versatile method for a variety of vinyl monomers, resulting in controlled molecular weights and low polydispersities. The surfaces produced by these methods not only possess superhydrophobicity but also have many applications, such as self-cleaning, self-healing, anti-icing, anti-bioadhesion, oil-water separation, and even superamphiphobic surfaces. Interestingly, the combination of responsive materials and roughness enhances the responsiveness, which allows the achievement of intelligent transformation between superhydrophobicity and superhydrophilicity. Nevertheless, surfaces with poor physical and chemical properties are generally unable to withstand the severe conditions of the outside world; thus, it is necessary to optimize the performances of such materials to yield durable superhydrophobic surfaces. To sum up, some challenges and perspectives regarding the future research and development of polymeric superhydrophobic surfaces are presented.
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Affiliation(s)
- Gang Wen
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062, People's Republic of China and State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
| | - ZhiGuang Guo
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062, People's Republic of China and State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
| | - Weimin Liu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
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57
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Facile electrochemical synthesis of anatase nano-architectured titanium dioxide films with reversible superhydrophilic behavior. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2016.10.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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58
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Yang H, Hu X, Su C, Liu Y, Chen R. Reversibly photo-switchable wettability of stearic acid monolayer modified bismuth-based micro-/nanomaterials. Phys Chem Chem Phys 2017; 19:31666-31674. [DOI: 10.1039/c7cp05848a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bismuth-based micro-/nanomaterials could realize reversibly switchable wettability between superhydrophobicity and superhydrophilicity under UV-visible irradiation and dark storage.
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Affiliation(s)
- Hao Yang
- School of Chemistry and Environmental Engineering and Key Laboratory for Green Chemical Process of Ministry of Education
- Wuhan Institute of Technology
- Wuhan
- P. R. China
| | - Xiaojing Hu
- School of Chemistry and Environmental Engineering and Key Laboratory for Green Chemical Process of Ministry of Education
- Wuhan Institute of Technology
- Wuhan
- P. R. China
| | - Chunping Su
- School of Chemistry and Environmental Engineering and Key Laboratory for Green Chemical Process of Ministry of Education
- Wuhan Institute of Technology
- Wuhan
- P. R. China
| | - Yunling Liu
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry
- Jilin University
- Changchun
- P. R. China
| | - Rong Chen
- School of Chemistry and Environmental Engineering and Key Laboratory for Green Chemical Process of Ministry of Education
- Wuhan Institute of Technology
- Wuhan
- P. R. China
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59
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Su Y, Zhang J, Liu K, Huang Z, Ren X, Wang CA. Simple synthesis of a double-shell hollow structured MnO2@TiO2 composite as an anode material for lithium ion batteries. RSC Adv 2017. [DOI: 10.1039/c7ra09628c] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A double-shell hollow structured MnO2@TiO2 anode material was fabricated through a simple two-step template method.
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Affiliation(s)
- Yibo Su
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing
- China
| | - Jian Zhang
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing
- China
| | - Kai Liu
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing
- China
| | - Zeya Huang
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing
- China
| | - Xiancang Ren
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing
- China
| | - Chang-An Wang
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing
- China
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60
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Xie Z, Shuang S, Ma L, Zhu F, Liu X, Zhang Z. Annealing effect on the photoelectrochemical and photocatalytic performance of TiO2 nanorod arrays. RSC Adv 2017. [DOI: 10.1039/c7ra09801d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The photoelectrochemical and photocatalytic properties of TiO2 nanorod arrays annealed in the air were investigated.
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Affiliation(s)
- Zheng Xie
- State Key Laboratory for New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Shuang Shuang
- State Key Laboratory for New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Lingwei Ma
- State Key Laboratory for New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Fei Zhu
- State Key Laboratory for New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | | | - Zhengjun Zhang
- State Key Laboratory for New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
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61
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Li H, Shang J, Zhu H, Yang Z, Ai Z, Zhang L. Oxygen Vacancy Structure Associated Photocatalytic Water Oxidation of BiOCl. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02613] [Citation(s) in RCA: 278] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hao Li
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
| | - Jian Shang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
| | - Huijun Zhu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
| | - Zhiping Yang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
| | - Zhihui Ai
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
| | - Lizhi Zhang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
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62
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UV Light⁻Induced Aggregation of Titania Submicron Particles. MICROMACHINES 2016; 7:mi7110203. [PMID: 30404376 PMCID: PMC6189861 DOI: 10.3390/mi7110203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 10/28/2016] [Accepted: 11/02/2016] [Indexed: 12/18/2022]
Abstract
In this study, aggregation of TiO2 (rutile and anatase) submicron particles in deionized (DI) water under ultra-violet (UV) light irradiation was investigated. While no aggregation was observed in the dark, rutile and anatase submicron particles started aggregating upon application of UV light and ceased aggregation in about 2 and 8.4 h, respectively. It has been demonstrated that UV light directly mitigated the particle mobility of TiO2, resulting in a neutralization effect of the Zeta potential. It was also observed that rutile particles aggregated much faster than anatase particles under UV radiation, indicating that the Zeta potential of as-prepared rutile is less than that of anatase in deionized (DI) water. In addition, the interaction energy of rutile and anatase particles was simulated using the Derjaguin–Landau–Verwey–Overbeek (DLVO) model. The results showed a significant reduction of barrier energy from 118.2 kBT to 33.6 kBT for rutile and from 333.5 kBT to 46.1 kBT for anatase, respectively, which further validated the remarkable influence of UV irradiation on the aggregation kinetics of rutile and anatase submicron particles. This work presents a further understanding of the aggregation mechanism of light-controlled submicron particles and has a promising potential application in environmental remediation.
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63
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Baccaro AL, Gutz IG. Quick cold preparation of TiO2 nanolayers on gold from P25 suspensions – film structure, voltammetric behavior and photocatalytic performance for the oxidation of EDTA under UVA-LED irradiation. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.08.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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64
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Nakate UT, Patil P, Bulakhe R, Lokhande C, Kale SN, Naushad M, Mane RS. Sprayed zinc oxide films: Ultra-violet light-induced reversible surface wettability and platinum-sensitization-assisted improved liquefied petroleum gas response. J Colloid Interface Sci 2016; 480:109-117. [DOI: 10.1016/j.jcis.2016.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 07/02/2016] [Accepted: 07/06/2016] [Indexed: 11/25/2022]
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65
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Ha S, Janissen R, Ussembayev YY, van Oene MM, Solano B, Dekker NH. Tunable top-down fabrication and functional surface coating of single-crystal titanium dioxide nanostructures and nanoparticles. NANOSCALE 2016; 8:10739-48. [PMID: 27160731 DOI: 10.1039/c6nr00898d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Titanium dioxide (TiO2) is a key component of diverse optical and electronic applications that exploit its exceptional material properties. In particular, the use of TiO2 in its single-crystalline phase can offer substantial advantages over its amorphous and polycrystalline phases for existing and yet-to-be-developed applications. However, the implementation of single-crystal TiO2 has been hampered by challenges in its fabrication and subsequent surface functionalization. Here, we introduce a novel top-down approach that allows for batch fabrication of uniform high-aspect-ratio single-crystal TiO2 nanostructures with targeted sidewall profiles. We complement our fabrication approach with a functionalization strategy that achieves dense, uniform, and area-selective coating with a variety of biomolecules. This allows us to fabricate single-crystal rutile TiO2 nanocylinders tethered with individual DNA molecules for use as force- and torque-transducers in an optical torque wrench. These developments provide the means for increased exploitation of the superior material properties of single-crystal TiO2 at the nanoscale.
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Affiliation(s)
- Seungkyu Ha
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
| | - Yera Ye Ussembayev
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
| | - Maarten M van Oene
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
| | - Belen Solano
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
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66
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Yamaguchi Y, Shimodo T, Usuki S, Torigoe K, Terashima C, Katsumata KI, Ikekita M, Fujishima A, Sakai H, Nakata K. Different hollow and spherical TiO2 morphologies have distinct activities for the photocatalytic inactivation of chemical and biological agents. Photochem Photobiol Sci 2016; 15:988-94. [DOI: 10.1039/c6pp00093b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
TiO2 hollows and spheres are a suitable morphology for photocatalytic decomposition of dimethyl sulfoxide and anti-pathogen performance, respectively.
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67
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Zhang W, Zhu L, Ye H, Liu H, Li W. Modifying a waterborne polyacrylate coating with a silica sol for enhancing anti-fogging performance. RSC Adv 2016. [DOI: 10.1039/c6ra19237h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
(A) Schematic chemical reaction of polyacrylate latexes and silica sol precursor; (B) evolution of water contact angle on various samples as a function of time; (C) anti-fogging properties of the polyacrylate/silica composite coating.
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Affiliation(s)
- Wenhui Zhang
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)
- School of Materials Science and Engineering
- Beihang University
- Beijing 100191
- China
| | - Liqun Zhu
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)
- School of Materials Science and Engineering
- Beihang University
- Beijing 100191
- China
| | - Hui Ye
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)
- School of Materials Science and Engineering
- Beihang University
- Beijing 100191
- China
| | - Huicong Liu
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)
- School of Materials Science and Engineering
- Beihang University
- Beijing 100191
- China
| | - Weiping Li
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)
- School of Materials Science and Engineering
- Beihang University
- Beijing 100191
- China
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68
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Takase K, Hyodo K, Morimoto M, Kojima Y, Mayama H, Yokojima S, Nakamura S, Uchida K. Photoinduced reversible formation of a superhydrophilic surface by crystal growth of diarylethene. Chem Commun (Camb) 2016; 52:6885-7. [DOI: 10.1039/c6cc01638c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The surface covered with lumpy crystals shows superhydrophilicity that can be reversibly controlled by alternating irradiation with UV and visible light.
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Affiliation(s)
- Kazuki Takase
- Department of Materials Chemistry
- Faculty of Science and Technology
- Ryukoku University
- Otsu
- Japan
| | - Kengo Hyodo
- Department of Materials Chemistry
- Faculty of Science and Technology
- Ryukoku University
- Otsu
- Japan
| | - Masakazu Morimoto
- Department of Chemistry and Research Center for Smart Molecules
- Rikkyo University
- Toshima-ku
- Japan
| | - Yuko Kojima
- MCHC R&D Synergy Center, Inc
- Yokohama 227-8502
- Japan
| | - Hiroyuki Mayama
- Department of Chemistry
- Asahikawa Medical University
- Asahikawa
- Japan
| | - Satoshi Yokojima
- School of Pharmacy
- Tokyo University of Pharmacy and Life Sciences
- Hachioji
- Japan
| | | | - Kingo Uchida
- Department of Materials Chemistry
- Faculty of Science and Technology
- Ryukoku University
- Otsu
- Japan
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69
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Smirnova N, Fesenko T, Zhukovsky M, Goworek J, Eremenko A. Photodegradation of Stearic Acid Adsorbed on Superhydrophilic TiO2 Surface: In Situ FT-IR and LDI Study. NANOSCALE RESEARCH LETTERS 2015; 10:500. [PMID: 26714862 PMCID: PMC4695485 DOI: 10.1186/s11671-015-1210-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/21/2015] [Indexed: 06/05/2023]
Abstract
TiO2 films prepared by template-assisted sol-gel method were characterized by X-ray diffraction spectroscopy, scanning and atomic force electron microscopy, and Fourier transform infrared (FT-IR) spectroscopy. Based on the hexane adsorption-desorption analysis, the films have a surface area of 390-540 m(2)/g with pore size distribution narrowly centered around 10 nm. Optimal component ratio and condition of heat treatment of mesoporous titania films have been found. Photocatalytic activity of the coatings was determined by the destruction of stearic acid layers, monitored using FT-IR spectroscopy and laser desorption-ionization (LDI) mass spectrometry. Under UV illumination, all the used films reach hydrophilicity with water contact angle of 0°. As the result, hydrophobic fat acid molecules undergo self-association and active desorption from the hydrophilic surface during mass-spectrometric experiment.
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Affiliation(s)
- Natalia Smirnova
- O.Chuiko Institute of Surface Chemistry, Ukrainian National Academy of Sciences, 17 General Naumov, Kyiv, 03680, Ukraine.
| | - Tatiana Fesenko
- O.Chuiko Institute of Surface Chemistry, Ukrainian National Academy of Sciences, 17 General Naumov, Kyiv, 03680, Ukraine.
| | - Maxim Zhukovsky
- O.Chuiko Institute of Surface Chemistry, Ukrainian National Academy of Sciences, 17 General Naumov, Kyiv, 03680, Ukraine.
| | - Jacek Goworek
- Faculty of Chemistry, Maria Curie-Skłodowska University, Pl. Maria Curie-Skłodowskiej 3, 2-031, Lublin, Poland.
| | - Anna Eremenko
- O.Chuiko Institute of Surface Chemistry, Ukrainian National Academy of Sciences, 17 General Naumov, Kyiv, 03680, Ukraine.
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70
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Zhang Y, Payne DT, Pang CL, Fielding H, Thornton G. Non-Band-Gap Photoexcitation of Hydroxylated TiO2. J Phys Chem Lett 2015; 6:3391-5. [PMID: 26267712 PMCID: PMC4603613 DOI: 10.1021/acs.jpclett.5b01508] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 08/12/2015] [Indexed: 06/04/2023]
Abstract
The photochemistry of TiO2 has been studied intensively since it was discovered that TiO2 can act as a photocatalyst. Nevertheless, it has proven difficult to establish the detailed charge-transfer processes involved, partly because the excited states involved are difficult to study. Here we present evidence of the existence of hydroxyl-induced excited states in the conduction band region. Using two-photon photoemission, we show that stepwise photoexcitation from filled band gap states lying 0.8 eV below the Fermi level of rutile TiO2(110) excites hydroxyl-induced states 2.73 eV above the Fermi level that has an onset energy of ∼3.1 eV. The onset is shifted to lower energy by the coadsorption of molecular water, which suggests a means of tuning the energy of the excited state.
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Affiliation(s)
- Yu Zhang
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
- London
Centre for Nanotechnology, University College
London, 17-19 Gordon
Street, London WC1H 0AH, United Kingdom
| | - Daniel T. Payne
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
- London
Centre for Nanotechnology, University College
London, 17-19 Gordon
Street, London WC1H 0AH, United Kingdom
| | - Chi L. Pang
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
- London
Centre for Nanotechnology, University College
London, 17-19 Gordon
Street, London WC1H 0AH, United Kingdom
| | - Helen
H. Fielding
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Geoff Thornton
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
- London
Centre for Nanotechnology, University College
London, 17-19 Gordon
Street, London WC1H 0AH, United Kingdom
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71
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Wang S, Liu K, Yao X, Jiang L. Bioinspired Surfaces with Superwettability: New Insight on Theory, Design, and Applications. Chem Rev 2015; 115:8230-93. [DOI: 10.1021/cr400083y] [Citation(s) in RCA: 1085] [Impact Index Per Article: 120.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
| | - Kesong Liu
- Key
Laboratory of Bio-Inspired Smart Interfacial Science and Technology
of Ministry of Education, School of Chemistry and Environment, BeiHang University, Beijing 100191, People’s Republic of China
| | - Xi Yao
- Department
of Biomedical Sciences, City University of Hong Kong, Hong Kong P6903, People’s Republic of China
| | - Lei Jiang
- Key
Laboratory of Bio-Inspired Smart Interfacial Science and Technology
of Ministry of Education, School of Chemistry and Environment, BeiHang University, Beijing 100191, People’s Republic of China
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72
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Bhavsar K, Ross D, Prabhu R, Pollard P. LED-controlled tuning of ZnO nanowires' wettability for biosensing applications. NANO REVIEWS 2015; 6:26711. [PMID: 25855065 PMCID: PMC4390563 DOI: 10.3402/nano.v6.26711] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 11/22/2022]
Abstract
Background Wettability is an important property of solid materials which can be controlled by surface energy. Dynamic control over the surface wettability is of great importance for biosensing applications. Zinc oxide (ZnO) is a biocompatible material suitable for biosensors and microfluidic devices. Nanowires of ZnO tend to show a hydrophobic nature which decelerates the adhesion or adsorption of biomolecules on the surface and, therefore, limits their application. Methods Surface wettability of the ZnO nanowires can be tuned using light irradiation. However, the control over wettability using light-emitting diodes (LEDs) and the role of wavelength in controlling the wettability of ZnO nanowires are unclear. This is the first report on LED-based wettability control of nanowires, and it includes investigations on tuning the desired wettability of ZnO nanowires using LEDs as a controlling tool. Results The investigations on spectral properties of the LED emission on ZnO nanowires’ wettability have shown strong dependency on the spectral overlap of LED emission on ZnO absorption spectra. Results indicate that LEDs offer an advanced control on dynamically tuning the wettability of ZnO nanowires. Conclusion The spectral investigations have provided significant insight into the role of irradiating wavelength of light and irradiation time on the surface wettability of ZnO nanowires. This process is suitable to realize on chip based integrated sensors and has huge potential for eco-friendly biosensing and environmental sensing applications.
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Affiliation(s)
| | - Duncan Ross
- IDEAS Research Institute, Robert Gordon University, Aberdeen, UK
| | | | - Pat Pollard
- IDEAS Research Institute, Robert Gordon University, Aberdeen, UK
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73
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Chen J, Yang P, Liao Y, Wang J, Chen H, Sun H, Huang N. Effect of the duration of UV irradiation on the anticoagulant properties of titanium dioxide films. ACS APPLIED MATERIALS & INTERFACES 2015; 7:4423-4432. [PMID: 25679095 DOI: 10.1021/am509006y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recently, UV irradiation has been reported as a new approach to significantly improve the anticoagulant properties of titanium dioxide (TiO2) films by suppressing fibrinogen adsorption and platelet adhesion. This study focuses on how fibrinogen adsorption of and platelet adhesion to TiO2 films is affected by the duration of UV irradiation. Furthermore, this study intends to describe the link between the suppression effect and the changes in the TiO2 films nature caused by photogenerated reactive oxygen species (ROS). First, we performed UV irradiation in different atmospheres as model 1 to determine the effect of oxygen gas on the anticoagulant properties of TiO2 films. The results showed that the suppression of platelet adhesion induced by UV irradiation depended on the presence of oxygen gas, indicating that ROS were photogenerated, and the ROS-induced surface change was related to the improvement in the anticoagulant ability. Then, we fabricated three other types of TiO2 samples in air by varying the UV irradiation time: (1) model 2, comprising fully UV-irradiated TiO2 films, (2) model 3, comprising partially UV-irradiated TiO2 films, and (3) model 4, comprising fully UV-irradiated TiO2-Si micropatterns. The results indicated that UV irradiation affected the anticoagulant properties of TiO2 films in a time-dependent manner. UV irradiation on TiO2 films for short duration (e.g., 1 min) evidenced a suppression effect on fibrinogen adsorption and platelet adhesion, an effect that could not be the result of photoinduced superhydrophilicity, increased hydroxyl groups (-OH) number, or decomposition of the adsorbed hydrocarbon. When the UV irradiation time was longer, this suppression effect extended from the surface of the UV-irradiated TiO2 films to the surface of the adjacent masked TiO2 films and the nearby Si surface. This result supported that the suppression effect could be related to the changes in the nature of the TiO2 films that were caused by the photogenerated and diffused ROS. Further, this extension of the suppression effect to the Si surface indicated that the photogenerated ROS could be used to improve the anticoagulant properties of other materials. A prolonged UV irradiation time (e.g., 240 min) may enhance the fibrinogen adsorption of and platelet adhesion to TiO2 films, which could be related to the decomposition of the adsorbed hydrocarbon and the increase in the positive charge. However, when comparing the enhancement effect and the suppression effect, the results showed that the latter was the main one to influence fibrinogen adsorption of and platelet adhesion to TiO2 films. This study provides an important basis for understanding the behavior of UV-irradiated TiO2 films as anticoagulant materials.
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Affiliation(s)
- Jiang Chen
- Institute of Biomaterials and Surface Engineering, Key Laboratory for Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University , Chengdu 610031, People's Republic of China
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74
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Wang S, Pan L, Song JJ, Mi W, Zou JJ, Wang L, Zhang X. Titanium-Defected Undoped Anatase TiO2 with p-Type Conductivity, Room-Temperature Ferromagnetism, and Remarkable Photocatalytic Performance. J Am Chem Soc 2015; 137:2975-83. [DOI: 10.1021/ja512047k] [Citation(s) in RCA: 430] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Songbo Wang
- Key
Laboratory for Green Chemical Technology of the Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Lun Pan
- Key
Laboratory for Green Chemical Technology of the Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Jia-Jia Song
- Key
Laboratory for Green Chemical Technology of the Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Wenbo Mi
- Tianjin
Key Laboratory of Low Dimensional Materials Physics and Preparation
Technology, Faculty of Science, Tianjin University, Tianjin 300072, China
| | - Ji-Jun Zou
- Key
Laboratory for Green Chemical Technology of the Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Li Wang
- Key
Laboratory for Green Chemical Technology of the Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Xiangwen Zhang
- Key
Laboratory for Green Chemical Technology of the Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
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75
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Silva Junior E, La Porta FA, Liu MS, Andrés J, Varela JA, Longo E. A relationship between structural and electronic order–disorder effects and optical properties in crystalline TiO2 nanomaterials. Dalton Trans 2015; 44:3159-75. [DOI: 10.1039/c4dt03254c] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The focus of this paper is on the analysis of the structural and electronic order–disorder effects at long, medium and short ranges of titanium dioxide (TiO2) nanoparticles synthesized by the sol–gel process followed by the microwave-assisted solvothermal (MAS) method.
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Affiliation(s)
- E. Silva Junior
- LIEC
- Instituto de Química
- Universidade Estadual Paulista
- CEP 14801-907 Araraquara
- Brazil
| | - F. A. La Porta
- LIEC
- Instituto de Química
- Universidade Estadual Paulista
- CEP 14801-907 Araraquara
- Brazil
| | - M. S. Liu
- Instituto de Física de São Carlos
- Universidade de São Paulo
- 13560-970 São Carlos
- Brazil
| | - J. Andrés
- Department of Physical and Analytical Chemistry
- Universitat Jaume I
- Castelló de la Plana
- Spain
| | - J. A. Varela
- LIEC
- Instituto de Química
- Universidade Estadual Paulista
- CEP 14801-907 Araraquara
- Brazil
| | - E. Longo
- LIEC
- Instituto de Química
- Universidade Estadual Paulista
- CEP 14801-907 Araraquara
- Brazil
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76
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Qin L, Zhao J, Lei S, Pan Q. A smart "strider" can float on both water and oils. ACS APPLIED MATERIALS & INTERFACES 2014; 6:21355-21362. [PMID: 25402567 DOI: 10.1021/am506317h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Aquatic devices that can work on both water and oils have great scientific and practical significance, but the challenge remains in developing novel materials with excellent repellence to both water and oils. Here, we report that an artificial "strider" can float on both water and oils by using supporting legs with ultraviolet (UV) switchable wettability. The legs were fabricated by immobilizing TiO2 nanoparticles and n-dodecanethiol onto copper foams via a simple mussel-inspired process. At ambient conditions, the strider floated freely on a water surface, but it dived in water and then stood stably at the interface of water/CHCl3 after UV illumination for 2 h. The reason for this unique behavior is that the legs changed their wettability from superhydrophobicity to underwater superoleophobicity after the illumination. It was revealed that the micro/nanohierarchical structures and photosensitivity of the immobilized TiO2 nanoparticles accounted for the switchable wettability and large supporting force of the legs. The findings of this study offer an alternative strategy for fabricating smart aquatic devices that might be used for water environment protection, water resource surveillance, oil spill cleanup, and so on.
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Affiliation(s)
- Liming Qin
- State Key Laboratory of Robotics and Systems, School of Chemical Engineering and Technology, Harbin Institute of Technology , Harbin 150001, People's Republic of China
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77
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Li H, Shi J, Zhao K, Zhang L. Sustainable molecular oxygen activation with oxygen vacancies on the {001} facets of BiOCl nanosheets under solar light. NANOSCALE 2014; 6:14168-14173. [PMID: 25329732 DOI: 10.1039/c4nr04810e] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate that oxygen vacancies on the {001} facets of BiOCl nanosheets can more sustainably activate molecular oxygen for organic pollutant removal under solar light than the TiO₂ counterparts. The oxygen vacancies on the {001} facets of BiOCl nanosheets are effectively refreshed by UV light, and are also responsible for the efficient utilization of visible light to activate molecular oxygen, accounting for their long term stability and high efficiency.
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Affiliation(s)
- Hao Li
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
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78
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The wettability of PTFE and glass surfaces by nanofluids. J Colloid Interface Sci 2014; 434:141-51. [DOI: 10.1016/j.jcis.2014.07.044] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/25/2014] [Accepted: 07/29/2014] [Indexed: 11/20/2022]
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79
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Schneider J, Matsuoka M, Takeuchi M, Zhang J, Horiuchi Y, Anpo M, Bahnemann DW. Understanding TiO2 Photocatalysis: Mechanisms and Materials. Chem Rev 2014; 114:9919-86. [DOI: 10.1021/cr5001892] [Citation(s) in RCA: 3847] [Impact Index Per Article: 384.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jenny Schneider
- Institut
für Technische Chemie, Leibniz Universität Hannover, Callinstrasse
3, D-30167 Hannover, Germany
| | - Masaya Matsuoka
- Faculty
of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan
| | - Masato Takeuchi
- Faculty
of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan
| | - Jinlong Zhang
- Key
Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China
| | - Yu Horiuchi
- Faculty
of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan
| | - Masakazu Anpo
- Faculty
of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan
| | - Detlef W. Bahnemann
- Institut
für Technische Chemie, Leibniz Universität Hannover, Callinstrasse
3, D-30167 Hannover, Germany
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80
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Asahi R, Morikawa T, Irie H, Ohwaki T. Nitrogen-Doped Titanium Dioxide as Visible-Light-Sensitive Photocatalyst: Designs, Developments, and Prospects. Chem Rev 2014; 114:9824-52. [DOI: 10.1021/cr5000738] [Citation(s) in RCA: 940] [Impact Index Per Article: 94.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Ryoji Asahi
- Toyota Central Research and Development Laboratories, Inc., Nagakute, Aichi 480-1192, Japan
| | - Takeshi Morikawa
- Toyota Central Research and Development Laboratories, Inc., Nagakute, Aichi 480-1192, Japan
| | - Hiroshi Irie
- Clean
Energy Research Center, University of Yamanashi, Kofu, Yamanashi 400-8511, Japan
| | - Takeshi Ohwaki
- Toyota Central Research and Development Laboratories, Inc., Nagakute, Aichi 480-1192, Japan
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81
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Ahmed F, Arshi N, Anwar MS, Danish R, Koo BH. Morphological evolution of ZnO nanostructures and their aspect ratio-induced enhancement in photocatalytic properties. RSC Adv 2014. [DOI: 10.1039/c4ra02470b] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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82
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83
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Lin ZH, Cheng G, Wu W, Pradel KC, Wang ZL. Dual-mode triboelectric nanogenerator for harvesting water energy and as a self-powered ethanol nanosensor. ACS NANO 2014; 8:6440-8. [PMID: 24785901 DOI: 10.1021/nn501983s] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
When water is passing through the air or an insulating tube, it will contain not only the mechanical energy but also the electrostatic energy due to the existence of triboelectric charges on its surface as a result of contact with the air/solid surface. In this paper, a hybrid triboelectric nanogenerator (TENG) is designed to simultaneously harvest the electrostatic and mechanical energies of flowing water. Water-TENG, mainly constructed by a superhydrophobic TiO2 layer with hierarchical micro/nanostructures, is used to collect the electrostatic energy of water (Output 1). Contact-TENG, composed by a polytetrafluoroethylene film and a layer of assembled SiO2 nanoparticles, is used to collect the mechanical energy of water (Output 1 and Output 2). Using TiO2 nanomaterials in water-TENG provides the advantages of photocatalytic activity and antibacterial property for water purification. Under the impact of a water stream from a household faucet at a flowing rate of 40 mL s(-1), the generated short-circuit current from Output 1 and Output 2 of dual-mode TENG can reach 43 and 18 μA, respectively. The instantaneous output power densities from Output 1 and Output 2 of dual-mode TENG are 1.31 and 0.38 W m(-2), respectively, when connecting to a load resistor of 44 MΩ. The rectified outputs have been applied to drive light-emitting diodes and charge commercial capacitors. Besides, the water-TENG has also been demonstrated as a self-powered nanosensor for ethanol detection.
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Affiliation(s)
- Zong-Hong Lin
- School of Material Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States
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84
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Liu K, Cao M, Fujishima A, Jiang L. Bio-Inspired Titanium Dioxide Materials with Special Wettability and Their Applications. Chem Rev 2014; 114:10044-94. [DOI: 10.1021/cr4006796] [Citation(s) in RCA: 427] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Kesong Liu
- Key
Laboratory of Bio-Inspired Smart Interfacial Science and Technology
of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing 100191, PR China
- Institute
for Superconducting and Electronic Materials, University of Wollongong, Innovation Campus, Squires Way, North Wollongong, NSW 2500, Australia
| | - Moyuan Cao
- Key
Laboratory of Bio-Inspired Smart Interfacial Science and Technology
of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing 100191, PR China
| | - Akira Fujishima
- Research
Institute for Science and Technology, Photocatalysis International
Research Center, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Lei Jiang
- Key
Laboratory of Bio-Inspired Smart Interfacial Science and Technology
of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing 100191, PR China
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
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85
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Zhang X, Qin J, Xue Y, Yu P, Zhang B, Wang L, Liu R. Effect of aspect ratio and surface defects on the photocatalytic activity of ZnO nanorods. Sci Rep 2014; 4:4596. [PMID: 24699790 PMCID: PMC3975220 DOI: 10.1038/srep04596] [Citation(s) in RCA: 316] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 03/20/2014] [Indexed: 12/23/2022] Open
Abstract
ZnO, aside from TiO2, has been considered as a promising material for purification and disinfection of water and air, and remediation of hazardous waste, owing to its high activity, environment-friendly feature and lower cost. However, their poor visible light utilization greatly limited their practical applications. Herein, we demonstrate the fabrication of different aspect ratios of the ZnO nanorods with surface defects by mechanical-assisted thermal decomposition method. The experiments revealed that ZnO nanorods with higher aspect ratio and surface defects show significantly higher photocatalytic performances.
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Affiliation(s)
- Xinyu Zhang
- 1] State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China [2]
| | - Jiaqian Qin
- 1] Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330, Thailand [2]
| | - Yanan Xue
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Pengfei Yu
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Bing Zhang
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Limin Wang
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Riping Liu
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China
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86
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Zheng JY, Bao SH, Guo Y, Jin P. Natural hydrophobicity and reversible wettability conversion of flat anatase TiO₂ thin film. ACS APPLIED MATERIALS & INTERFACES 2014; 6:1351-1355. [PMID: 24387162 DOI: 10.1021/am404470e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Flat anatase TiO2 thin film deposited at room temperature shows the natural hydrophobicity, which is destroyed by 400 °C vacuum annealing. On the basis of the analysis of surface composition and structure, the origin of hydrophobicity of the flat TiO2 film can be identified as (1) approximately fully stoichiometric TiO2 and (2) hydrocarbon adsorbates on the film surface. We further validate that interfacial water molecules near the surface of the as-prepared TiO2 film are oriented in the hydrophobic hydration structure via Fourier transform infrared/attenuated total reflection. Moreover, the as-prepared TiO2 film also shows a smart surface reversibly switched between hydrophobicity and super-hydrophilicity. During the recovery process of hydrophobicity, the irradiated films show the wettability with water contact angle of 107 ± 1.7, 72 ± 2.5, 80 ± 1.1, and 17 ± 1.3° corresponding to after a week of exposure to ambient air, O2, CF4, and Ar, respectively. It can be strongly reinforced that the stoichiometry and the adsorbates both play an important role in forming the hydrophobic TiO2 films.
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Affiliation(s)
- Jian-Yun Zheng
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences , Shanghai 200050, China
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87
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Ubba E, Nawaz Khan FR, Jeong ED, Chung EH. TiO2 nano crystallites catalyzed water mediated microwave assisted regioselective three component domino hydrolysis/aldol condensation/Michael addition reaction of 3-(1,5-dioxo-1,5-diphenylpentan-3-yl)quinolin-2(1H)-one. RSC Adv 2014. [DOI: 10.1039/c4ra10051d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microwave supported, water intervened, nano crystalline TiO2 catalyzed synthesis of 3-(1,5-dioxo-1,5-diphenylpentan-3-yl)quinolin-2(1H)-ones, is described.
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Affiliation(s)
- Eethamukkala Ubba
- Organic and Medicinal Chemistry Research Laboratory
- Organic Chemistry Division
- School of Advanced Sciences
- VIT-University
- Vellore 632 014, India
| | - Fazlur-Rahman Nawaz Khan
- Organic and Medicinal Chemistry Research Laboratory
- Organic Chemistry Division
- School of Advanced Sciences
- VIT-University
- Vellore 632 014, India
| | - Euh Duck Jeong
- Korea Basic Science Institute
- Busan Center
- Busan 618 230, South Korea
| | - Eun Hyuk Chung
- Korea Basic Science Institute
- Busan Center
- Busan 618 230, South Korea
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88
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Fundamentals on Adsorption, Membrane Filtration, and Advanced Oxidation Processes for Water Treatment. NANOTECHNOLOGY FOR WATER TREATMENT AND PURIFICATION 2014. [DOI: 10.1007/978-3-319-06578-6_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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89
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Xu C, Yang W, Guo Q, Dai D, Chen M, Yang X. Suppression of Photoinduced BBO Defects Generation on TiO2(110) by Water. CHINESE J CHEM PHYS 2013. [DOI: 10.1063/1674-0068/26/06/646-650] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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90
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Huang WX, Huang H, Li H, Zhou ZH, Chen H. Superhydrophilic nano-TiO2 film with porous surface structure. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/143289109x12494867167486] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- W. X. Huang
- Guangdong Provincial Key Lab for Green Chemical Product Technology School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, China
| | - H. Huang
- Guangdong Provincial Key Lab for Green Chemical Product Technology School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, China
| | - H. Li
- Guangdong Provincial Key Lab for Green Chemical Product Technology School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, China
| | - Z. H. Zhou
- Guangdong Provincial Key Lab for Green Chemical Product Technology School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, China
| | - H. Chen
- Guangdong Provincial Key Lab for Green Chemical Product Technology School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510640, China
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91
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Diamanti MV, Gadelrab KR, Pedeferri MP, Stefancich M, Pehkonen SO, Chiesa M. Nanoscale investigation of photoinduced hydrophilicity variations in anatase and rutile nanopowders. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:14512-14518. [PMID: 24152147 DOI: 10.1021/la4034723] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The photoactive properties of TiO2 are employed to develop surfaces with self-cleaning capabilities. Clearly, the fine-tuning of such surfaces for different applications relies on a holistic understanding of the different aspects that induce the self-cleaning behavior. Among those, the mechanisms responsible for the photoinduced surface alteration in the TiO2 allotropes are still not completely understood. In this study, TiO2 polymorphs nanopowders are investigated by combining the high spatial resolution observables of recently developed atomic force microscopy (AFM) based force spectroscopy techniques with diffuse reflection infrared Fourier transform spectroscopy (DRIFTS). Phase maps under irradiated and nonirradiated conditions for anatase and rutile suggest the existence of two distinct behaviors that are further discerned by energy analysis of amplitude and phase vs distance curves. Independently, surface analysis of anatase and rutile by means of DRIFTS spectroscopy reveals a readily distinguishable coexistence of dissociated water and molecular water on the two phases, confirming the stronger photoactivity of anatase. The peculiarity of the surface interaction under UV exposure is further investigated by reconstructing the force profiles between the oscillating AFM tip and the TiO2 phases with the attempt of gaining a better understanding of the mechanisms that cause the different hydrophilic properties in the TiO2 allotropes.
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Affiliation(s)
- M V Diamanti
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano , Via Mancinelli 7, 20131 Milan, Italy
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92
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Improved Texturing and Photocatalytic Efficiency in TiO2Films Grown Using Aerosol-Assisted CVD and Atmospheric Pressure CVD. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/cvde.201307067] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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93
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Yang M, Neupane S, Wang X, He J, Li W, Pala N. Multiple step growth of single crystalline rutile nanorods with the assistance of self-assembled monolayer for dye sensitized solar cells. ACS APPLIED MATERIALS & INTERFACES 2013; 5:9809-9815. [PMID: 24033252 DOI: 10.1021/am4030092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel multiple step growth (MSG) process has been developed to synthesize rutile nanorods (NRs) on fluorine-doped tin oxide (FTO) glass with the assistance of a self-assembled monolayer (SAM) aiming to increase the internal surface area of the 1D materials for dye sensitized solar cell (DSSC) applications. The experimental result reveals that the SAM layer can be selectively decomposed at the tip of the nanorod, namely the rutile (001) surface, due to the anisotropic photocatalytic property of the rutile. The remaining SAM layer on the side-wall of the NRs remains intact and serves as water repellent which prevents the radial growth of the NRs during the next step hydrothermal synthesis; therefore, the spacing between the NRs and the porosity of the NR array can be retained after additional growth cycles. On the other hand, introduction of a middle layer formed via TiCl4 solution treatment before the next growth cycle is found to be an effective way to control the diameters of the newly grown NRs. The performance of DSSC made from the rutile NRs grown using the MSG technique has been examined, and it is significantly affected by the internal surfaces of the NRs. Furthermore, the MSG combined with NR etching treatment by acid at low temperature (150 °C) leads to a significant enhancement in the solar cell performance. The gigantic wettability difference of the NRs before and after the SAM treatment as well as the MSG method could be adapted to prepare superhydrophobic and superhydrophilic nanostructured patterns for other applications.
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Affiliation(s)
- Mengjin Yang
- Department of Physics, Florida International University , Miami, Florida 33199, United States
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94
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Cui X, Jiang Z. Cyclic Voltammetric and Ac Impedance Behavior of TiO2Electrodes under UV Illumination. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200300141] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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95
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He G, Pan G, Zhang M. Assembling structures and dynamics properties of perfluorooctane sulfonate (PFOS) at water–titanium oxide interfaces. J Colloid Interface Sci 2013; 405:189-94. [DOI: 10.1016/j.jcis.2013.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 04/26/2013] [Accepted: 05/01/2013] [Indexed: 10/26/2022]
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96
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Anastasiadis SH. Development of functional polymer surfaces with controlled wettability. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9277-9290. [PMID: 23789943 DOI: 10.1021/la400533u] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
There is a demand for surfaces with new functional properties in almost all industrial branches. During the next few years, research input will be required for the development of coatings exhibiting an easy-to-clean or self-cleaning ability, switchability so that they can act as sensors/actuators, and defined tribological/mechanical properties and long-term stability. To achieve such behavior, the development of new advanced functional coatings that exhibit the proper chemistry and surface structure is necessary. In this Feature Article, we provide a review of the research activities in our laboratory on the development of functional and, especially, reversibly switchable polymer surfaces where the emphasis is on controlling their wettability. We will first discuss the fabrication of superhydrophobic surfaces by hierarchically micro- and nanostructuring a substrate surface with an ultrafast laser followed by appropriate hydrophobization. Then, we will summarize the development of surfaces that can alter their wetting behavior in response to changes in external stimuli such as humidity and light illumination. Finally, we will present our investigations on utilizing responsive (organic) coatings on hierarchically roughened substrates for the development of surfaces, which would be able to switch reversibly from superhydrophilic to superhydrophobic and water-repellent in response to an external stimulus (in this case, pH).
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Affiliation(s)
- Spiros H Anastasiadis
- Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, P.O. Box 1527, 711 10 Heraklion Crete, Greece.
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97
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Park JJ, Kim DY, Latthe SS, Lee JG, Swihart MT, Yoon SS. Thermally induced superhydrophilicity in TiO2 films prepared by supersonic aerosol deposition. ACS APPLIED MATERIALS & INTERFACES 2013; 5:6155-6160. [PMID: 23758802 DOI: 10.1021/am401083y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Superhydrophilic and superhydrophobic surfaces enable self-cleaning phenomena, either forming a continuous water film or forming droplets that roll off the surface, respectively. TiO2 films are well-known for their extreme hydrophilicity and photocatalytic characteristics. Here, we describe nanostructured TiO2 thin films prepared by supersonic aerosol deposition, including a thorough study of the effects of the annealing temperature on the crystal structure, surface morphology, surface roughness, and wetting properties. Powder X-ray diffraction showed that supersonic deposition resulted in fragmentation and amorphization of the micrometer-size anatase (60%)-rutile (40%) precursor powder and that, upon annealing, a substantial fraction of the film (~30%) crystallized in the highly hydrophilic but metastable brookite phase. The film morphology was also somewhat modified after annealing. Scanning electron microscopy and atomic force microscopy revealed rough granular films with high surface roughness. The as-deposited TiO2 films were moderately hydrophilic with a water contact angle (θ) of ~45°, whereas TiO2 films annealed at 500 °C became superhydrophilic (θ ~ 0°) without UV illumination. This thermally induced superhydrophilicity of the TiO2 films can be explained on the basis of the combined effects of the change in the crystal structure, surface microstructure, and surface roughness. Supersonic aerosol deposition followed by annealing is uniquely able to produce these nanostructured films containing a mixture of all three TiO2 phases (anatase, rutile, and brookite) and exhibiting superhydrophilicity without UV illumination.
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Affiliation(s)
- Jung-Jae Park
- Department of Mechanical Engineering, Korea University, Seoul 136-713, Korea
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98
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Katsumata KI, Okayasu Y, Matsushita N, Okada K. Crystal-face Dependence of Photoinduced Hydrophilic Conversion on SrTiO3 Surfaces. CHEM LETT 2013. [DOI: 10.1246/cl.130115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Yuki Okayasu
- Materials and Structures Laboratory, Tokyo Institute of Technology
| | | | - Kiyoshi Okada
- Materials and Structures Laboratory, Tokyo Institute of Technology
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99
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Yan J, Wu G, Guan N, Li L, Li Z, Cao X. Understanding the effect of surface/bulk defects on the photocatalytic activity of TiO2: anatase versus rutile. Phys Chem Chem Phys 2013; 15:10978-88. [PMID: 23708180 DOI: 10.1039/c3cp50927c] [Citation(s) in RCA: 230] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The sole effect of surface/bulk defects of TiO2 samples on their photocatalytic activity was investigated. Nano-sized anatase and rutile TiO2 were prepared by hydrothermal method and their surface/bulk defects were adjusted simply by calcination at different temperatures, i.e. 400-700 °C. High temperature calcinations induced the growth of crystalline sizes and a decrease in the surface areas, while the crystalline phase and the exposed facets were kept unchanged during calcination, as indicated by the characterization results from XRD, Raman, nitrogen adsorption-desorption, TEM and UV-Vis spectra. The existence of surface/bulk defects in calcined TiO2 samples was confirmed by photoluminescence and XPS spectra, and the surface/bulk defect ratio was quantitatively analyzed according to positron annihilation results. The photocatalytic activity of calcined TiO2 samples was evaluated in the photocatalytic reforming of methanol and the photocatalytic oxidation of α-phenethyl alcohol. Based on the characterization and catalytic results, a direct correlation between the surface specific photocatalytic activity and the surface/bulk defect density ratio could be drawn for both anatase TiO2 and rutile TiO2. The surface defects of TiO2, i.e. oxygen vacancy clusters, could promote the separation of electron-hole pairs under irradiation, and therefore, enhance the activity during photocatalytic reaction.
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Affiliation(s)
- Junqing Yan
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, PR China
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100
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Dutta K, Kundu PP. Amphiphiles as hydrophobicity regulator: Fine tuning the surface hydrophobicity of an electropolymerized film. J Colloid Interface Sci 2013; 397:192-8. [DOI: 10.1016/j.jcis.2013.01.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/21/2013] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
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