1
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Zi B, Zheng H, Zhou T, Lu Q, Chen M, Xiao B, Zhang Y, Qiu Z, Sun H, Zhao J, Luo Z, He T, Zhang J, Zhao Z, Liu Q. Changeable Active Sites by Pr Doping CuSA-TiO 2 Photocatalyst for Excellent Hydrogen Production. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2305779. [PMID: 38764279 DOI: 10.1002/smll.202305779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 12/19/2023] [Indexed: 05/21/2024]
Abstract
Photocatalytic water splitting for clean hydrogen production has been a very attractive research field for decades. However, the insightful understanding of the actual active sites and their impact on catalytic performance is still ambiguous. Herein, a Pr-doped TiO2-supported Cu single atom (SA) photocatalyst is successfully synthesized (noted as Cu/Pr-TiO2). It is found that Pr dopants passivate the formation of oxygen vacancies, promoting the density of photogenerated electrons on the CuSAs, and optimizing the electronic structure and H* adsorption behavior on the CuSA active sites. The photocatalytic hydrogen evolution rate of the obtained Cu/Pr-TiO2 catalyst reaches 32.88 mmol g-1 h-1, 2.3 times higher than the Cu/TiO2. Innovatively, the excellent catalytic activity and performance is attributed to the active sites change from O atoms to CuSAs after Pr doping is found. This work provides new insight for understanding the accurate roles of single atoms in photocatalytic water splitting.
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Affiliation(s)
- Baoye Zi
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Hongshun Zheng
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Tong Zhou
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Qingjie Lu
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Mingpeng Chen
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Bin Xiao
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Yumin Zhang
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Zhishi Qiu
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Huachuan Sun
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Jianhong Zhao
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Zhongge Luo
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Tianwei He
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Jin Zhang
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
| | - Zongyan Zhao
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Qingju Liu
- National Center for International Research on Photoelectric and Energy Materials, Yunnan Key Laboratory for Micro/nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming, 650091, China
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Wang K, Luo Z, Xiao B, Zhou T, Zhao J, Shen C, Li D, Qiu Z, Zhang J, He T, Liu Q. S-scheme Cu 3P/TiO 2 heterojunction for outstanding photocatalytic water splitting. J Colloid Interface Sci 2023; 652:1908-1916. [PMID: 37690298 DOI: 10.1016/j.jcis.2023.08.174] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/12/2023]
Abstract
TiO2 photocatalysts are of great interest in the fields of environmental purification, new energy and so on, because of their non-toxicity, high stability, high redox ability and low cost. However, the photogenerated carriers are severely recombined, which limits the application of TiO2 photocatalysts. Herein, S-scheme Cu3P/TiO2 heterojunction composites were successfully synthesized by a simple and efficient microwave hydrothermal method, and the results show that the hydrogen production rate of Cu3P/TiO2 is 5.83 mmol∙g-1∙h-1 under simulated sunlight irradiation, which is 7.3 and 83.3 times higher than that of pure TiO2 and Cu3P, respectively. This excellent performance is derived from the internal electric field (IEF) and energy band bending generated by the S-scheme heterojunction formed between Cu3P and TiO2. The density functional theory (DFT) calculation indicates that the Cu3P possess smaller work function and more negative conduction band (CB) position than that of TiO2, which is very conducive to greatly improve the H+ reduction ability and hydrogen production performance. This work provides a new idea for the reveal of electron transfer paths and active sites in S-scheme heterojunctions and deepens the mechanism understanding.
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Affiliation(s)
- Kexin Wang
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Zhongge Luo
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Bin Xiao
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Tong Zhou
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Jianhong Zhao
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Congcong Shen
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Dequan Li
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Zhishi Qiu
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Jin Zhang
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Tianwei He
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China
| | - Qingju Liu
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China.
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Belekbir S, El Azzouzi M, Rodríguez-Lorenzo L, El Hamidi A, Santaballa JA, Canle M. Cobalt Impregnation on Titania Photocatalysts Enhances Vis Phenol Photodegradation. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16114134. [PMID: 37297268 DOI: 10.3390/ma16114134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/15/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023]
Abstract
One of the main challenges of photocatalysis is to find a stable and effective photocatalyst, that is active and effective under sunlight. Here, we discuss the photocatalytic degradation of phenol as a model pollutant in aqueous solution using NUV-Vis (>366 nm) and UV (254 nm) in the presence of TiO2-P25 impregnated with different concentrations of Co (0.1%, 0.3%, 0.5%, and 1%). The modification of the surface of the photocatalyst was performed by wet impregnation, and the obtained solids were characterized using X-ray diffraction, XPS, SEM, EDS, TEM, N2 physisorption, Raman and UV-Vis DRS, which revealed the structural and morphological stability of the modified material. BET isotherms are type IV, with slit-shaped pores formed by nonrigid aggregate particles and no pore networks and a small H3 loop near the maximum relative pressure. The doped samples show increased crystallite sizes and a lower band gap, extending visible light harvesting. All prepared catalysts showed band gaps in the interval 2.3-2.5 eV. The photocatalytic degradation of aqueous phenol over TiO2-P25 and Co(X%)/TiO2 was monitored using UV-Vis spectrophotometry: Co(0.1%)/TiO2 being the most effective with NUV-Vis irradiation. TOC analysis showed ca. 96% TOC removal with NUV-Vis radiation, while only 23% removal under UV radiation.
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Affiliation(s)
- Soukayna Belekbir
- Laboratory of Nanomaterials, Nanotechnologies and Environment, Center of Materials Science, Faculty of Sciences, Mohammed V University in Rabat, Rabat BP 1014, Morocco
| | - Mohammed El Azzouzi
- Laboratory of Nanomaterials, Nanotechnologies and Environment, Center of Materials Science, Faculty of Sciences, Mohammed V University in Rabat, Rabat BP 1014, Morocco
| | - Laura Rodríguez-Lorenzo
- INL-International Iberian Nanotechnology Laboratory, Water Quality Group, Av. Mestre José Veiga, 4715-330 Braga, Portugal
| | - Adnane El Hamidi
- Laboratory of Nanomaterials, Nanotechnologies and Environment, Center of Materials Science, Faculty of Sciences, Mohammed V University in Rabat, Rabat BP 1014, Morocco
| | - Juan Arturo Santaballa
- React! Group, Department of Chemistry, Faculty of Sciences & CICA, University of A Coruña, E-15071 A Coruña, Spain
| | - Moisés Canle
- React! Group, Department of Chemistry, Faculty of Sciences & CICA, University of A Coruña, E-15071 A Coruña, Spain
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Gao L, Han D, Wang Z, Gu F. Metal-organic framework MIL-68(In)-NH2-derived carbon-covered cobalt-doped bi-crystalline In2O3 tubular structures for efficient photocatalytic degradation of tetracycline hydrochloride. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2023.130931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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5
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Bimetallic TiO 2 Nanoparticles for Lignin-Based Model Compounds Valorization by Integrating an Optocatalytic Flow-Microreactor. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248731. [PMID: 36557862 PMCID: PMC9785458 DOI: 10.3390/molecules27248731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022]
Abstract
The challenge of improving the activity of TiO2 by modifying it with metals and using it for targeted applications in microreactor environments is an active area of research. Recently, microreactors have emerged as successful candidates for many photocatalytic reactions, especially for the selective oxidation process. The current work introduces ultrasound-assisted catalyst deposition on the inner walls of a perfluoro-alkoxy alkane (PFA) microtube under mild conditions. We report Cu-Au/TiO2 and Fe-Au/TiO2 nanoparticles synthesized using the sol-gel method. The obtained photocatalysts were thoroughly characterized by UV-Vis diffuse-reflectance spectroscopy (DRS), high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and N2 physisorption. The photocatalytic activity under UV (375 nm) and visible light (515 nm) was estimated by the oxidation of lignin-based model aromatic alcohols in batch and fluoropolymer-based flow systems. The bimetallic catalyst exhibited improved photocatalytic selective oxidation. Herein, four aromatic alcohols were individually investigated and compared. In our experiments, the alcohols containing hydroxy and methoxy groups (coniferyl and vanillin alcohol) showed high conversion (93% and 52%, respectively) with 8% and 17% selectivity towards their respective aldehydes, with the formation of other side products. The results offer an insight into ligand-to-metal charge transfer (LMCT) complex formation, which was found to be the main reason for the activity of synthesized catalysts under visible light.
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Ibarra-Rodriguez LI, Pantoja-Espinoza JC, Luévano-Hipólito E, Garay-Rodríguez LF, López-Ortiz A, Torres-Martínez LM, Collins-Martínez VH. Formic acid and hydrogen generation from the photocatalytic reduction of CO2 on visible light activated N-TiO2/CeO2/CuO composites. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2022. [DOI: 10.1016/j.jpap.2022.100125] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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7
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Hasan I, Alharthi FA. Caffeine-Alginate Immobilized CeTiO4 Bionanocomposite for Efficient Photocatalytic Degradation of Methylene Blue. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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8
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Pradhan SR, Lisovytskiy D, Colmenares JC. Flow photomicroreactor coated with monometal containing TiO2 using sonication: A versatile tool for visible light oxidation. CATAL COMMUN 2022. [DOI: 10.1016/j.catcom.2021.106375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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9
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Suwondo KP, Aprilita NH, Wahyuni ET. Enhancement of TiO2 photocatalytic activity under visible light by doping with Cu from electroplating wastewater. REACTION KINETICS MECHANISMS AND CATALYSIS 2022. [DOI: 10.1007/s11144-021-02134-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Zhou Z, Deng J, Zhang X, Chen J, Liu J, Wang Z. Theoretical design of SnS 2-graphene heterojunctions with vacancy and impurity defects for multi-purpose photoelectric devices. Phys Chem Chem Phys 2021; 24:966-974. [PMID: 34914818 DOI: 10.1039/d1cp04552k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
SnS2 with atomic thickness has attracted extensive attention in the field of photocatalysis due to its special physicochemical properties, suitable band gap, low cost and low environmental toxicity. However, the application of SnS2 in the field of optoelectronics is restricted by its low photocatalytic efficiency and carrier mobility. In this study, vacancies and transition metal atoms are introduced into a SnS2 monolayer to modulate its physicochemical properties. Meanwhile, the SnS2 monolayer modified by vacancies and transition metal atoms is combined with graphene to form a heterostructure, which promotes the separation of photogenerated electron-hole pairs. The results of theoretical calculations show that the SnS2/graphene heterojunction can promote the separation of photogenerated carriers in intrinsic monolayer SnS2, and improve the photocatalytic efficiency and carrier mobility. The modification of Sn vacancies and Fe, Co atoms not only expands the visible light response range of the SnS2/graphene heterojunction, but also introduces magnetism, which is expected to be applied in spin optoelectronic materials. In this work, defects, doping and heterojunction assembly are rationally integrated, which provides a new idea for the design and development of spin optoelectronic devices based on monolayer SnS2.
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Affiliation(s)
- Zhonghao Zhou
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, China.
| | - Jianjun Deng
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, China.
| | - Xingchen Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, China.
| | - Jinglong Chen
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, China.
| | - Jia Liu
- No. 24 Research Institute, China Electronics Technology Group Corporation, Chongqing 401332, China
| | - Zhiyong Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, China.
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Solar active Cu2+-ZnS Photocatalyst for efficient photodegradation of 4-chlorophenol: effective cation doping effect. Catal Today 2021. [DOI: 10.1016/j.cattod.2020.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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12
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Lv T, Xiao B, Zhou S, Zhao J, Wu T, Zhang J, Zhang Y, Liu Q. Rich oxygen vacancies, mesoporous TiO 2 derived from MIL-125 for highly efficient photocatalytic hydrogen evolution. Chem Commun (Camb) 2021; 57:9704-9707. [PMID: 34555135 DOI: 10.1039/d1cc01669e] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we report a mesoporous TiO2 with a large specific surface area and rich oxygen vacancies using a Ti-based MOF (MIL-125) as a precursor through high-temperature annealing. Such integration of a unique mesoporous structure and oxygen vacancies provides effective carrier transport channels, increases surface active sites, and enhances photocatalytic activity for the hydrogen evolution reaction.
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Affiliation(s)
- Tianping Lv
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Bin Xiao
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Shiqiang Zhou
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Jianhong Zhao
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Tai Wu
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Jin Zhang
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Yumin Zhang
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
| | - Qingju Liu
- Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
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Matussin SN, Tan AL, Harunsani MH, Cho MH, Khan MM. Green and Phytogenic Fabrication of Co-Doped SnO2 Using Aqueous Leaf Extract of Tradescantia spathacea for Photoantioxidant and Photocatalytic Studies. BIONANOSCIENCE 2021. [DOI: 10.1007/s12668-020-00820-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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Facile Synthesis of "Boron-Doped" Carbon Dots and Their Application in Visible-Light-Driven Photocatalytic Degradation of Organic Dyes. NANOMATERIALS 2020; 10:nano10081560. [PMID: 32784435 PMCID: PMC7466398 DOI: 10.3390/nano10081560] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 07/30/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023]
Abstract
Carbon dots (C-dots) were facilely fabricated via a hydrothermal method and fully characterized. Our study shows that the as-synthesized C-dots are nontoxic, negatively charged spherical particles (average diameter 4.7 nm) with excellent water dispersion ability. Furthermore, the C-dots have a rich presence of surface functionalities such as hydroxyls and carboxyls as well as amines. The significance of the C-dots as highly efficient photocatalysts for rhodamine B (RhB) and methylene blue (MB) degradation was explored. The C-dots demonstrate excellent photocatalytic activity, achieving 100% of RhB and MB degradation within 170 min. The degradation rate constants for RhB and MB were 1.8 × 10−2 and 2.4 × 10−2 min−1, respectively. The photocatalytic degradation performances of the C-dots are comparable to those metal-based photocatalysts and generally better than previously reported C-dots photocatalysts. Collectively considering the excellent photocatalytic activity toward organic dye degradation, as well as the fact that they are facilely synthesized with no need of further doping, compositing, and tedious purification and separation, the C-dots fabricated in this work are demonstrated to be a promising alternative for pollutant degradation and environment protection.
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Fernandes S, Esteves da Silva JC, Pinto da Silva L. Life Cycle Assessment of the Sustainability of Enhancing the Photodegradation Activity of TiO 2 with Metal-Doping. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E1487. [PMID: 32218246 PMCID: PMC7178238 DOI: 10.3390/ma13071487] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 12/13/2022]
Abstract
While TiO2 nanoparticles have shown potential as photocatalysts in the degradation of organic contaminants, their inability to absorb efficiently visible light has limited their industrial application. One strategy for solving this problem is monodoping TiO2 photocatalysts with transition metals, which has worked in the degradation of several pollutants. However, it is not clear if this improvement is enough to offset the potential environmental impacts of adding metal ions to the synthesis of TiO2. Herein, we have used Life Cycle Assessment (LCA) to determine the sustainability of monodoping TiO2 with transition metals (Fe, Co, Mn and Ni, with a 1% weight ratio) to enhance the photocatalytic properties of the photocatalyst toward the degradation of Carbamazepine and Methyl Orange, under UV-A and visible light irradiation. We found that the addition of transition-metals has no significant effect on the environmental impacts associated with the synthesis of TiO2, when a weight-based functional unit was considered. However, when photocatalytic activity was considered, major differences were found. Thus, our results demonstrate that the sustainability of monodoping with different transition metals is solely determined by their ability to enhance (or not) the photocatalytic activity of TiO2. Our data also demonstrated that isopropyl alcohol constitutes a critical point in the synthesis of TiO2 photocatalysts, with ethanol being a potential substitute.
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Affiliation(s)
- Sónia Fernandes
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; (S.F.)
| | - Joaquim C.G. Esteves da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; (S.F.)
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environmental and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal
| | - Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; (S.F.)
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environmental and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal
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Nawaz A. Composite of natural bamboo (Dendrocalamus strictus) and TiO2: Its photocatalytic potential in the degradation of methylene blue under the direct irradiation of solar light. RESEARCH ON CHEMICAL INTERMEDIATES 2020. [DOI: 10.1007/s11164-020-04116-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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17
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Study of TiO2-Modified Sol Coating Material in the Protection of Stone-Built Cultural Heritage. COATINGS 2020. [DOI: 10.3390/coatings10020179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coating materials can effectively protect stone-built cultural heritage and, as such, research into coating materials has gained comprehensive attention from researchers. The aim of this work is to prepare a TiO2-modified sol coating material (TSCM) and study its protective effects on stone-built cultural heritage. TSCM and pure TiO2 sol (p-sol, unmodified; for comparison) were applied evenly over the entire surface of stone samples. The prepared stone samples included untreated stone, stone treated with pure sol, and stone treated with TSCM. The protective effects of TSCM were evaluated by water absorption, water vapor permeability, acid resistance, and weather resistance experiments. The results show that stone treated with TSCM has excellent water absorption and water vapor permeability, strong acid resistance, and good weather resistance, compared with untreated stone or stone treated with p-sol. The acid resistance of stone treated by TSCM was 1.75 times higher than that treated with traditional coating materials. The weather resistance cycle number of stone treated by TSCM was four times higher than that treated with organic protective materials. These findings are expected to provide useful suggestions for the protection of stone-built cultural heritage.
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Liao C, Li Y, Tjong SC. Visible-Light Active Titanium Dioxide Nanomaterials with Bactericidal Properties. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E124. [PMID: 31936581 PMCID: PMC7022691 DOI: 10.3390/nano10010124] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 12/16/2022]
Abstract
This article provides an overview of current research into the development, synthesis, photocatalytic bacterial activity, biocompatibility and cytotoxic properties of various visible-light active titanium dioxide (TiO2) nanoparticles (NPs) and their nanocomposites. To achieve antibacterial inactivation under visible light, TiO2 NPs are doped with metal and non-metal elements, modified with carbonaceous nanomaterials, and coupled with other metal oxide semiconductors. Transition metals introduce a localized d-electron state just below the conduction band of TiO2 NPs, thereby narrowing the bandgap and causing a red shift of the optical absorption edge into the visible region. Silver nanoparticles of doped TiO2 NPs experience surface plasmon resonance under visible light excitation, leading to the injection of hot electrons into the conduction band of TiO2 NPs to generate reactive oxygen species (ROS) for bacterial killing. The modification of TiO2 NPs with carbon nanotubes and graphene sheets also achieve the efficient creation of ROS under visible light irradiation. Furthermore, titanium-based alloy implants in orthopedics with enhanced antibacterial activity and biocompatibility can be achieved by forming a surface layer of Ag-doped titania nanotubes. By incorporating TiO2 NPs and Cu-doped TiO2 NPs into chitosan or the textile matrix, the resulting polymer nanocomposites exhibit excellent antimicrobial properties that can have applications as fruit/food wrapping films, self-cleaning fabrics, medical scaffolds and wound dressings. Considering the possible use of visible-light active TiO2 nanomaterials for various applications, their toxicity impact on the environment and public health is also addressed.
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Affiliation(s)
- Chengzhu Liao
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuchao Li
- Department of Materials Science and Engineering, Liaocheng University, Liaocheng 252000, China;
| | - Sie Chin Tjong
- Department of Physics, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong 999077, China
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El Mragui A, Logvina Y, Pinto da Silva L, Zegaoui O, Esteves da Silva JC. Synthesis of Fe- and Co-Doped TiO 2 with Improved Photocatalytic Activity Under Visible Irradiation Toward Carbamazepine Degradation. MATERIALS 2019; 12:ma12233874. [PMID: 31771256 PMCID: PMC6926595 DOI: 10.3390/ma12233874] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 11/26/2022]
Abstract
Pure TiO2 and Fe- and Co-doped TiO2 nanoparticles (NPs) as photocatalysts were synthesized using wet chemical methods (sol-gel + precipitation). Their crystalline structure and optical properties were analyzed using X-ray diffraction (XRD), Raman spectroscopy and Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible light (UV-Vis) diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of the synthesized nanoparticles was evaluated through degradation of carbamazepine (CBZ) under UV-A and visible-light irradiations. The XRD and Raman analyses revealed that all synthesized nanomaterials showed only the anatase phase. The DRS results showed that the absorption edge was blue-shifted for Fe-doped TiO2 NPs. The decrease in charge recombination was evidenced from the PL investigation for both Co-doped and Fe-doped TiO2 nanomaterials. An enhancement in photocatalytic degradation of carbamazepine in aqueous suspension under both UV-A light and visible-light irradiations was observed for Fe-doped Titania NPs by comparison with pure TiO2. These results suggest that the doping cations could suppress the electron/hole recombination. Therefore, the photocatalytic activity of TiO2-based nanomaterials was enhanced.
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Affiliation(s)
- Abderrahim El Mragui
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, Rua do Campo Alegre 697, 4169-007 Porto, Portugal; (A.E.M.); (Y.L.); (L.P.d.S.)
- Research team “Materials and Applied Catalysis: MCA”, “CBAE” Laboratory, Faculty of Sciences, Moulay Ismail University, BP.11201 Zitoune, Meknès, Morocco;
| | - Yuliya Logvina
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, Rua do Campo Alegre 697, 4169-007 Porto, Portugal; (A.E.M.); (Y.L.); (L.P.d.S.)
| | - Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, Rua do Campo Alegre 697, 4169-007 Porto, Portugal; (A.E.M.); (Y.L.); (L.P.d.S.)
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences, University of Porto, Rua do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Omar Zegaoui
- Research team “Materials and Applied Catalysis: MCA”, “CBAE” Laboratory, Faculty of Sciences, Moulay Ismail University, BP.11201 Zitoune, Meknès, Morocco;
| | - Joaquim C.G. Esteves da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, Rua do Campo Alegre 697, 4169-007 Porto, Portugal; (A.E.M.); (Y.L.); (L.P.d.S.)
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences, University of Porto, Rua do Campo Alegre 697, 4169-007 Porto, Portugal
- Correspondence: ; Tel.: +351-220-402-569
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