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Oppong-Antwi L, Huang B, Hart JN. Electronic Properties of Transition and Alkaline Earth Metal Doped CuS: A DFT Study. Chemphyschem 2023:e202300417. [PMID: 37792575 DOI: 10.1002/cphc.202300417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/11/2023] [Indexed: 10/06/2023]
Abstract
CuS is a unique semiconductor with potential in optoelectronics. Its unusual electronic structure, including a partially occupied valence band, and complex crystal structure with an S-S bond offer unique opportunities and potential applications. In this work, the use of doping to optimize the properties of CuS for various applications is investigated by density functional theory (DFT) calculations. Among the dopants studied, Ni, Zn, and Mg may be the most practical due to their lower formation energies. Doping with Fe, Ni, or Ca induces significant distortion, which may be beneficial for achieving materials with high surface areas and active states. Significantly, doping alters the conductor-like behavior of CuS, opening a band gap by increasing bond ionicity and reducing the S-S bond covalency. Thus, doping CuS can tune the plasmonic properties and transform it from a conductor to an intrinsic fluorescent semiconductor. Ni and Fe doping give the lowest band gaps (0.35 eV and 0.39 eV, respectively), while Mg doping gives the highest (0.86 eV). Doping with Mg, Ca, and Zn may enhance electron mobility and charge separation. Most dopants increase the anisotropy of electron-to-hole mass ratios, enabling device design that exploits directional-dependence for improved performance.
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Affiliation(s)
- Louis Oppong-Antwi
- School of Materials Science and Engineering, UNSW, Sydney, NSW, 2052, Australia
| | - Bosi Huang
- School of Materials Science and Engineering, UNSW, Sydney, NSW, 2052, Australia
| | - Judy N Hart
- School of Materials Science and Engineering, UNSW, Sydney, NSW, 2052, Australia
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2
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Olatomiwa A, Adam T, Edet C, Adewale A, Chik A, Mohammed M, Gopinath SC, Hashim U. Recent advances in density functional theory approach for optoelectronics properties of graphene. Heliyon 2023; 9:e14279. [PMID: 36950613 PMCID: PMC10025043 DOI: 10.1016/j.heliyon.2023.e14279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023] Open
Abstract
Graphene has received tremendous attention among diverse 2D materials because of its remarkable properties. Its emergence over the last two decades gave a new and distinct dynamic to the study of materials, with several research projects focusing on exploiting its intrinsic properties for optoelectronic devices. This review provides a comprehensive overview of several published articles based on density functional theory and recently introduced machine learning approaches applied to study the electronic and optical properties of graphene. A comprehensive catalogue of the bond lengths, band gaps, and formation energies of various doped graphene systems that determine thermodynamic stability was reported in the literature. In these studies, the peculiarity of the obtained results reported is consequent on the nature and type of the dopants, the choice of the XC functionals, the basis set, and the wrong input parameters. The different density functional theory models, as well as the strengths and uncertainties of the ML potentials employed in the machine learning approach to enhance the prediction models for graphene, were elucidated. Lastly, the thermal properties, modelling of graphene heterostructures, the superconducting behaviour of graphene, and optimization of the DFT models are grey areas that future studies should explore in enhancing its unique potential. Therefore, the identified future trends and knowledge gaps have a prospect in both academia and industry to design future and reliable optoelectronic devices.
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Affiliation(s)
- A.L. Olatomiwa
- Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis, Malaysia
- Faculty of Electronic Engineering and Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
| | - Tijjani Adam
- Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis, Malaysia
- Faculty of Electronic Engineering and Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
- Micro System Technology, Centre of Excellence (CoE), Universiti Malaysia Perlis (UniMAP), Pauh Campus, 02600, Arau, Perlis, Malaysia
| | - C.O. Edet
- Faculty of Electronic Engineering and Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
- Institute of Engineering Mathematics, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
- Department of Physics, Cross River University of Technology, Calabar, Nigeria
| | - A.A. Adewale
- Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdullah Chik
- Centre for Frontier Materials Research, Universiti Malaysia Perlis, 01000, Kangar, Perlis, Malaysia
- Faculty of Chemical Engineering and Technology, Universiti Malaysia Perlis (UniMAP), Taman Muhibbah, Jejawi, 02600, Arau, Perlis, Malaysia
| | - Mohammed Mohammed
- Faculty of Chemical Engineering and Technology, Universiti Malaysia Perlis (UniMAP), Taman Muhibbah, Jejawi, 02600, Arau, Perlis, Malaysia
- Center of Excellence Geopolymer & Green Technology (CEGeoGTech), Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia
| | - Subash C.B. Gopinath
- Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis, Malaysia
- Micro System Technology, Centre of Excellence (CoE), Universiti Malaysia Perlis (UniMAP), Pauh Campus, 02600, Arau, Perlis, Malaysia
- Faculty of Chemical Engineering and Technology, Universiti Malaysia Perlis (UniMAP), Taman Muhibbah, Jejawi, 02600, Arau, Perlis, Malaysia
| | - U. Hashim
- Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis, Malaysia
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3
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AlSalhi MS, Devanesan S, Asemi N, Ahamed A. Concurrent fabrication of ZnO-ZnFe 2O 4 hybrid nanocomposite for enhancing photocatalytic degradation of organic pollutants and its bacterial inactivation. CHEMOSPHERE 2023; 318:137928. [PMID: 36706811 DOI: 10.1016/j.chemosphere.2023.137928] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/24/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
In this research, we looked at how heterostructure fabrication, phase ratio, and crystalline nature affect the photocatalytic activity of ZnO/ZnFe2O4 nanocomposite for the degradation of Rhodamine B (RhB) dye when exposed to sunlight irradiation. Magnetic ZnO/ZnFe2O4 hybrid nanocomposites were made using a co-precipitation technique. The synthesized hybrid nanocomposite were analyzed using a variety of characterization techniques to understand more about their chemical, crystallinity, and photoactive characteristics. Using UV-Visible spectra, the absorption and photocatalytic efficiency of photocatalysts were investigated. By using XPS and FTIR measurements, the surface composition and functionalization of the produced nanocomposite were observed. The synthesized ZnO/ZnFe2O4 nanocomposites exhibit irregular morphologies, and the average crystallite size is about 30 nm, by the findings of the transmission electron microscope. When exposed to solar light for 90 min, the prepared photocatalysts exceed ZnO nanoparticles in terms of photocatalytic performance by more than 45%. Pseudo-first-order kinetics governs the adsorption of RhB onto nanocomposite surfaces. Finally, the ZnO/ZnFe2O4 nanocomposites were employed for antibacterial treatments against the waterborne pathogens Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). The outcomes demonstrated that the optimal disinfection efficiency against E. coli and S. aureus germs were 98.6 and 97.4%, respectively, associated with superior cycling durability. Therefore, this work offers a simple and rapid approach to the development of hybrid nanocomposites that could be used to create various photocatalytic and optical materials.
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Affiliation(s)
- Mohamad S AlSalhi
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
| | - Sandhanasamy Devanesan
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
| | - Nassar Asemi
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Anis Ahamed
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
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4
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Tayouri MI, Estaji S, Mousavi SR, Salkhi Khasraghi S, Jahanmardi R, Nouranian S, Arjmand M, Khonakdar HA. Degradation of polymer nanocomposites filled with graphene oxide and reduced graphene oxide nanoparticles: A review of current status. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.110179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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5
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Zhang W, Ji W, Yan W, Wang Z, Ling L, Hao X, Guan G. Enhanced electroactivity of BiOCl/PPy hybrid film with anamnestic lattice site for synergistically efficient selective uptake/release of chloride ions. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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6
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Khan H, Ashraf MU, Idrees M, Din HU, Nguyen CV, Amin B. Intriguing interfacial characteristics of the CS contact with MX 2 (M = Mo, W; X = S, Se, Te) and MXY ((X ≠ Y) = S, Se, Te) monolayers. RSC Adv 2022; 12:12292-12302. [PMID: 35480342 PMCID: PMC9036409 DOI: 10.1039/d2ra00668e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/08/2022] [Indexed: 11/27/2022] Open
Abstract
Using (hybrid) first principles calculations, the electronic band structure, type of Schottky contact and Schottky barrier height established at the interface of the most stable stacking patterns of the CS–MX2 (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH are investigated. The electronic band structures of CS–MX2 and CS–MXY MS vdWH seem to be simple sum of CS, MX2 and MXY monolayers. The projected electronic properties of the CS, MX2 and MXY layers are well preserved in CS–MX2 and CS–MXY MS vdWH. Their smaller effective mass (higher carrier mobility) render promising prospects of CS–WS2 and CS–MoSeTe as compared to other MS vdWH in nanoelectronic and optoelectronic devices, such as a high efficiency solar cell. In addition, we found that the effective mass of holes is higher than that of electrons, suggesting that these heterostructures can be utilized for hole/electron separation. Interestingly, the MS contact led to the formation of a Schottky contact or ohmic contact, therefore we have used the Schottky Mott rule to calculate the Schottky barrier height (SBH) of CS–MX2 (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH. It was found that CS–MX2 (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) (in both model-I and -II) MS vdWH form p-type Schottky contacts. These p-type Schottky contacts can be considered a promising building block for high-performance photoresponsive optoelectronic devices, p-type electronics, CS-based contacts, and for high-performance electronic devices. Electronic band structure, type of Schottky contact and Schottky barrier height established at the interface of the CS–MX2 (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH.![]()
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Affiliation(s)
- H. Khan
- Department of Physics, Abbottabad University of Science & Technology, Abbottabad, 22010, Pakistan
| | - M. U. Ashraf
- Department of Physics, Abbottabad University of Science & Technology, Abbottabad, 22010, Pakistan
| | - M. Idrees
- Department of Physics, Abbottabad University of Science & Technology, Abbottabad, 22010, Pakistan
| | - H. U. Din
- Department of Physics, Bacha Khan University, Charsadda, 24420, Pakistan
| | - Chuong V. Nguyen
- Department of Materials Science and Engineering, Le Quy Don Technical University, Hanoi 100000, Vietnam
| | - B. Amin
- Department of Physics, Abbottabad University of Science & Technology, Abbottabad, 22010, Pakistan
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7
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Opoku F, Osei-Bonsu Oppong S, Aniagyei A, Akoto O, Adimado AA. Boosting the photocatalytic H 2 evolution activity of type-II g-GaN/Sc 2CO 2 van der Waals heterostructure using applied biaxial strain and external electric field. RSC Adv 2022; 12:7391-7402. [PMID: 35424662 PMCID: PMC8982186 DOI: 10.1039/d2ra00419d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 02/26/2022] [Indexed: 01/17/2023] Open
Abstract
Two-dimensional (2D) van der Waals (vdW) heterostructures are a new class of materials with highly tunable bandgap transition type, bandgap energy and band alignment. Herein, we have designed a novel 2D g-GaN/Sc2CO2 heterostructure as a potential solar-driven photocatalyst for the water splitting process and investigate its catalytic stability, interfacial interactions, and optical and electronic properties, as well as the effects of applying an electric field and biaxial strain using first-principles calculation. The calculated lattice mismatch and binding energy showed that g-GaN and Sc2CO2 are in contact and may form a stable vdW heterostructure. Ab initio molecular dynamics and phonon dispersion simulations show thermal and dynamic stability. g-GaN/Sc2CO2 has an indirect bandgap energy with appropriate type-II band alignment relative to the water redox potentials. Meanwhile, the interfacial charge transfer from g-GaN to Sc2CO2 can effectively separate electron–hole pairs. Moreover, a potential drop of 3.78 eV is observed across the interface, inducing a built-in electric field pointing from g-GaN to Sc2CO2. The heterostructure shows improved visible-light optical absorption compared to the isolated g-GaN and Sc2CO2 monolayers. Our study demonstrates that tunable electronic and structural properties can be realised in the g-GaN/Sc2CO2 heterostructure by varying the electric field and biaxial strain. In particular, the compressive strain and negative electric field are more effective for promoting hydrogen production performance. Since it is challenging to tune the electric field and biaxial strain experimentally, our research provides strategies to boost the performance of MXene-based heterojunction photocatalysts in solar harvesting and optoelectronic devices. Type-II g-GaN/Sc2CO2 van der Waals heterostructure with electronic properties has potential for nanoelectronics, optoelectronics and photovoltaic device applications.![]()
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Affiliation(s)
- Francis Opoku
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Albert Aniagyei
- Department of Basic Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Osei Akoto
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Anthony Apeke Adimado
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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8
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Noor S, Sajjad S, Leghari SAK, Flox C, Ahmad S. Competitive role of nitrogen functionalities of N doped GO and sensitizing effect of Bi 2O 3 QDs on TiO 2 for water remediation. J Environ Sci (China) 2021; 108:107-119. [PMID: 34465425 DOI: 10.1016/j.jes.2021.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 06/13/2023]
Abstract
The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots (BQDs) doped TiO2 with nitrogen doped graphene oxide (NGO) nanocomposite (NGO/BQDs-TiO2) was fabricated. It was used for degradation of organic pollutants like 2,4-dichlorophenol (2,4-DCP) and stable dyes, i.e. Rhodamine B and Congo Red. X-ray diffraction (XRD) profile of NGO showed reduction in oxygenic functional groups and restoring of graphitic crystal structure. The characteristic diffraction peaks of TiO2 and its composites showed crystalline anatase TiO2. Morphological images represent spherical shaped TiO2 evenly covered with BQDs spread on NGO sheet. The surface linkages of NO-O-Ti, C-O-Ti, Bi-O-Ti and vibrational modes are observed by Fourier transform infrared spectroscopy (FTIR) and Raman studies. BQDs and NGO modified TiO2 results into red shifting in visible region as studied in diffused reflectance spectroscopy (DRS). NGO and BQDs in TiO2 are linked with defect centers which reduced the recombination of free charge carriers by quenching of photoluminescence (PL) intensities. X-ray photoelectron spectroscopy (XPS) shows that no peak related to C-O in NGO/BQDs-TiO2 is observed. This indicated that doping of nitrogen into GO has reduced some oxygen functional groups. Nitrogen functionalities in NGO and photosensitizing effect of BQDs in ternary composite have improved photocatalytic activity against organic pollutants. Intermediate byproducts during photo degradation process of 2,4-DCP were studied through high performance liquid chromatography (HPLC). Study of radical scavengers indicated that O2·- has significant role for degradation of 2,4-DCP. Our investigations propose that fabricated nanohybrid architecture has potential for degradation of environmental pollutions.
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Affiliation(s)
- Saima Noor
- International Islamic University, Islamabad 44000, Pakistan; Department of Chemistry and Materials Science, Aalto University, Espoo 16100, Fl-00076, Finland
| | - Shamaila Sajjad
- International Islamic University, Islamabad 44000, Pakistan.
| | | | - Cristina Flox
- Department of Chemistry and Materials Science, Aalto University, Espoo 16100, Fl-00076, Finland
| | - Saeed Ahmad
- Department of Applied Physics, Aalto University, Espoo 15100, Fl-00076, Finland
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9
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Albukhari SM, Ismail AA. Highly Dispersed Pt Nanoparticle-Doped Mesoporous ZnO Photocatalysts for Promoting Photoconversion of CO 2 to Methanol. ACS OMEGA 2021; 6:23378-23388. [PMID: 34549137 PMCID: PMC8444330 DOI: 10.1021/acsomega.1c03259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Photoreduction of CO2 is considered a challenge due to the lack of effective photocatalysts with wide-spectrum absorption, active charge separation dynamically, and CO2 adsorption. Herein, mesoporous Pt/ZnO nanocomposites with different Pt percentages (0.5-2%) have been fabricated using the sol-gel process in the presence of a template for CO2 photoreduction during visible-light exposure. Pt nanoparticles (NPs) deposited onto mesoporous ZnO with a considerable surface area can effectively promote charge mobility. The mesoporous 1.5% Pt/ZnO nanocomposite exhibits an optimal CH3OH yield (668 μmol g-1), which is 18.5-fold larger than that of mesoporous ZnO (36 μmol g-1). The most photoactive material was the 1.5% Pt/ZnO nanocomposite, producing CH3OH of 668 μmol g-1, and the production rate of CH3OH over the 1.5% Pt/ZnO nanocomposite (74.11 μmol g-1 h-1) was increased 20 times in comparison with ZnO NPs (3.72 μmol g-1 h-1). The enhancement of CO2 photoreduction efficiency over Pt/ZnO nanocomposites was attributed to the formation of the heterojunction at the Pt/ZnO interface, promoting a lower resistance to charge transfer and a larger electron transfer to the conduction band. Mesoporous Pt/ZnO nanocomposites offer enhanced accessibility and a larger surface area. Such an unparalleled mesostructure provides a new framework for the construction and design of photoactive materials with high-efficiency photocatalysts.
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Affiliation(s)
- Soha M. Albukhari
- Chemistry
Department, Faculty of Science, King Abdulaziz
University, P.O. Box 80200, Jeddah 21589, Saudi Arabia
| | - Adel. A. Ismail
- Central
Metallurgical R&D Institute, CMRDI, P.O. Box 87, Helwan, Cairo 11421, Egypt
- Nanotechnology
and Advanced Materials Program, Energy & Building Research Center, Kuwait Institute for Scientific Research (KISR), P.O. Box 24885, Safat 13109, Kuwait
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Saha JK, Billah MM, Jang J. Triple-Stack ZnO/AlZnO/YZnO Heterojunction Oxide Thin-Film Transistors by Spray Pyrolysis for High Mobility and Excellent Stability. ACS APPLIED MATERIALS & INTERFACES 2021; 13:37350-37362. [PMID: 34325511 DOI: 10.1021/acsami.1c07478] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We demonstrate a high mobility, triple-stack ZnO/AlZnO/YZnO heterojunction thin-film transistor (TFT) using the semiconductors deposited by spray pyrolysis at 350 °C on an Al2O3 gate insulator. A thin layer (5 nm) of AlZnO on the top of ZnO used as an active layer of an inverted coplanar-structured TFT increases the field-effect mobility (μFE) from 42.56 to 82.7 cm2 V-1 s-1. An additional 5 nm thick YZnO on the top of the ZnO/AlZnO TFT improves the electrical stability by reducing the defects in the bulk ZnO, AlZnO, and at the interface AlOx/ZnO. The ZnO-based materials show a nanocrystalline structure with the grain size less than 20 nm. The triple-stack oxide TFT shows a μFE of 71.3 cm2 V-1 s-1 with a threshold voltage (VTH) of 2.85 V. The hysteresis voltage for pristine ZnO, ZnO/AlZnO, and ZnO/AlZnO/YZnO TFTs is 0.52, 0.24, and 0.02 V, respectively. The ZnO/AlZnO/YZnO TFT shows a negligible VTH shift under temperature bias stress for 3600 s at 60 °C and excellent environmental stability over a few months, which is due to the presence of stronger Y-O and Al-O bonds in the back channel. The threshold voltage shift under positive bias temperature stress for pristine ZnO, ZnO/AlZnO, and ZnO/AlZnO/YZnO TFTs is 0.78, 0.40, and 0.15 V, respectively. Compared to the pristine ZnO TFT, the ZnO/AlZnO/YZnO TFT shows better environmental and bias stabilities with improved hysteresis. The experimental data of ZnO/AlZnO and ZnO/AlZnO/YZnO TFTs can be fitted by technology computer-aided design (TCAD) simulation using the density of states model of the oxide semiconductors. From the TCAD simulation, it is found that a 2D-like electron gas is formed at the narrow AlZnO layer between ZnO and YZnO.
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Affiliation(s)
- Jewel Kumer Saha
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Department of Physics, Jagannath University, Dhaka 1100, Bangladesh
| | - Mohammad Masum Billah
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Jin Jang
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
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11
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Mohammed MH, Hanoon FH. Application of zinc oxide nanosheet in various anticancer drugs delivery: Quantum chemical study. INORG CHEM COMMUN 2021. [DOI: 10.1016/j.inoche.2021.108522] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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12
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Biswal HJ, Yadav A, Vundavilli PR, Gupta A. High aspect ZnO nanorod growth over electrodeposited tubes for photocatalytic degradation of EtBr dye. RSC Adv 2021; 11:1623-1634. [PMID: 35424085 PMCID: PMC8693598 DOI: 10.1039/d0ra08124h] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/07/2020] [Indexed: 01/03/2023] Open
Abstract
In this work, vertically grown rod type ZnO nanostructures have been synthesized on metallic nickel tube films fabricated through the cost-effective process of electroforming. The use of tubular metal substrates for the growth of ZnO nanorods has been found to be advantageous for the photocatalytic degradation of EtBr dye because of their high surface area-to-volume ratio. The nickel tubes with ZnO nanorods were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The developed system was utilized for the photocatalytic degradation of EtBr dye and its efficacy was revealed through the comprehensive mineralization of the dye within 150 min. The mechanism of the degradation process has been revealed through total organic carbon (TOC), chemical oxygen demand (COD) and high-performance liquid chromatography (HPLC) studies. A substantially lower amount of the photocatalyst has been used because of the homogeneously distributed growth of nanorods on the substrate. Density functional theory-based analysis has also been performed to study the photocatalytic degradation and adsorption properties of EtBr on ZnO nanorods. Using first principles DFT theory, geometry optimizations and vibrational analysis are performed which show a negative charge transfer from the substrate to the photocatalyst. For the first time this article reports the use of DFT analysis for investigating the adsorption of EtBr on ZnO nanorods, and the experimental growth of nanorods over electroformed Ni tubes.
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Affiliation(s)
- Hrudaya Jyoti Biswal
- School of Mechanical Sciences, Indian Institute of Technology Bhubaneswar Odisha 752050 India
| | - Anshul Yadav
- Membrane Science and Separation Technology Division, CSIR-Central Salt and Marine Chemicals Research Institute Bhavnagar 364002 Gujarat India
| | - Pandu R Vundavilli
- School of Mechanical Sciences, Indian Institute of Technology Bhubaneswar Odisha 752050 India
| | - Ankur Gupta
- Department of Mechanical Engineering, Indian Institute of Technology Jodhpur Rajasthan 342037 India
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13
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Opoku F, Akoto O, Oppong SOB, Adimado AA. Two-dimensional layered type-II MS 2/BiOCl (M = Zr, Hf) van der Waals heterostructures: promising photocatalysts for hydrogen generation. NEW J CHEM 2021. [DOI: 10.1039/d1nj03867b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Our theoretical findings reveal that in-plane biaxial strain tunes the bandgap and induces a transition from indirect to direct semiconductor.
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Affiliation(s)
- Francis Opoku
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Osei Akoto
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Anthony Apeke Adimado
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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14
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Synthesis, Characterization, and Photocatalytic Performance of ZnO–Graphene Nanocomposites: A Review. JOURNAL OF COMPOSITES SCIENCE 2020. [DOI: 10.3390/jcs5010004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ZnO is an exciting material for photocatalysis applications due to its high activity, easy accessibility of raw materials, low production costs, and nontoxic. Several ZnO nano and microstructures can be obtained, such as nanoparticles, nanorods, micro flowers, microspheres, among others, depending on the preparation method and conditions. ZnO is a wide bandgap semiconductor presenting massive recombination of the generated charge carriers, limiting its photocatalytic efficiency and stability. It is common to mix it with metal, metal oxide, sulfides, polymers, and nanocarbon-based materials to improve its photocatalytic behavior. Therefore, ZnO–nanocarbon composites formation has been a viable alternative that leads to new, more active, and stable photocatalytic systems. Mainly, graphene is a well-known two-dimensional material, which could be an excellent candidate to hybridize with ZnO due to its excellent physical and chemical properties (e.g., high specific surface area, optical transmittance, and thermal conductivity, among others). This review analyses ZnO–graphene nanocomposites’ recent advances, addressing the synthesis methods and the resulting structural, morphological, optical, and electronic properties. Moreover, we examine the ZnO–graphene composites’ role in the photocatalytic degradation of organic/inorganic pollutants.
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Varadwaj PR, Marques HM. The Cs 2AgRhCl 6 Halide Double Perovskite: A Dynamically Stable Lead-Free Transition-Metal Driven Semiconducting Material for Optoelectronics. Front Chem 2020; 8:796. [PMID: 33195026 PMCID: PMC7655969 DOI: 10.3389/fchem.2020.00796] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/29/2020] [Indexed: 01/05/2023] Open
Abstract
A-Site doping with alkali ions, and/or metal substitution at the B and B'-sites, are among the key strategies in the innovative development of A 2BB'X6 halide double perovskite semiconducting materials for application in energy and device technologies. To this end, we have investigated an intriguing series of five halide-based non-toxic systems, A 2AgRhCl6 (A = Li, Na, K, Rb, and Cs), using density functional theory at the SCAN-rVV10 level. The lattice stability and bonding properties emanating from this study of A 2AgRhCl6 matched well with those that have already been synthesized, characterized and discussed [viz. Cs2AgBiX6 (X = Cl, Br)]. Exploration of traditional and recently proposed tolerance factors has enabled us to identify A 2AgRhCl6 (A = K, Rb and Cs) as stable double perovskites. The band structure and density of states calculations suggested that the electronic transition from the top of the valence band [Cl(3p)+Rh(4d)] to the bottom of the conduction band [(Cl(3p)+Rh(4d)] is inherently direct at the X-point of the first Brillouin zone. The (non-spin polarized) bandgap of these materials was found in the range 0.57-0.65 eV with SCAN-rVV10, which were substantially smaller than those computed with hybrid HSE06 and PBE0, and quasi-particle GW methods. This, together with the appreciable refractive index and high absorption coefficient in the region covering the range 1.0-4.5 eV, enabled us to demonstrate that A 2AgRhCl6 (A = K, Rb, and Cs) are likely candidate materials for photoelectric applications. The results of our phonon calculations at the harmonic level suggested that the Cs2AgRhCl6 is the only system that is dynamically stable (no imaginary frequencies found around the high symmetry lines of the reciprocal lattice), although the elastic moduli properties suggested all five systems examined are mechanically stable.
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Affiliation(s)
- Pradeep R. Varadwaj
- Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
| | - Helder M. Marques
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
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16
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Ullattil SG, Jabeen Fatima MJ, Abdel-Wahab A. Defect minimized Ag-ZnO microneedles for photocatalysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:37036-37043. [PMID: 32577972 PMCID: PMC7456407 DOI: 10.1007/s11356-020-09433-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
A facile solution processing strategy has been developed for the formation of Ag-modified ZnO microneedles at various calcination temperatures such as 300, 500, and 700 °C (AZ3, AZ5, and AZ7 respectively). Due to the heavy doping of AgNO3, Ag+ ions have been incorporated in to the crystal lattice of ZnO in all the Ag-ZnO samples, which facilitated the formation of Ag-ZnO microneedle morphology with minimized defect states, and obviously, the plasmon peaks were observed due to Ag modification. These Ag-ZnO microneedle structures have been evaluated for their photocatalytic performance using methylene blue as model target contaminant and their activity was compared with the commercially available titania P25 photocatalyst. The photoactivity of all the Ag-ZnO microneedle structures was significantly higher than that of the commercially available P25 photocatalyst with the most active Ag-ZnO material having a photocatalytic activity ~ 1.4 times greater than that of P25 titania.
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Affiliation(s)
- Sanjay Gopal Ullattil
- Chemical Engineering Program, Texas A&M University at Qatar, 23874, Education City, Doha, Qatar.
| | - M J Jabeen Fatima
- Department of Nanoscience and Technology, University of Calicut, Malappuram, Kerala, 673635, India
| | - Ahmed Abdel-Wahab
- Chemical Engineering Program, Texas A&M University at Qatar, 23874, Education City, Doha, Qatar.
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17
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Idrees M, Nguyen CV, Bui HD, Ahmad I, Amin B. van der Waals heterostructures based on MSSe (M = Mo, W) and graphene-like GaN: enhanced optoelectronic and photocatalytic properties for water splitting. Phys Chem Chem Phys 2020; 22:20704-20711. [PMID: 32901640 DOI: 10.1039/d0cp03434g] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The geometric structure, electronic, optical and photocatalytic properties of MSSe-g-GaN (M = Mo, W) van der Waals (vdW) heterostructures are investigated by performing first-principles calculations. We find that the MoSSe-g-GaN heterostructure exhibits type-II band alignment for all stacking patterns. While the WSSe-g-GaN heterostructure forms the type-II or type-I band alignment for the stacking model-I or model II, respectively. The average electrostatic potential shows that the potential of g-GaN is deeper than the MSSe monolayer, leading to the formation of an electrostatic field across the interface, causing the transfer of photogenerated electrons and holes. Efficient interfacial formation of interface and charge transfer reduce the work function of MSSe-g-GaN vdW heterostructures as compared to the constituent monolayer. The difference in the carrier mobility for electrons and holes suggests that these heterostructures could be utilized for hole/electron separation. Absorption spectra demonstrate that strong absorption from infrared to visible light in these vdW heterostructures can be achieved. Appropriate valence and conduction band edge positions with standard redox potentials provide enough force to drive the photogenerated electrons and holes to dissociate water into H+/H2 and O2/H2O at pH = 0.
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Affiliation(s)
- M Idrees
- Department of Physics, Hazara University, Mansehra 21300, Pakistan
| | - Chuong V Nguyen
- Department of Materials Science and Engineering, Le Quy Don Technical University, Ha Noi 100000, Vietnam.
| | - H D Bui
- Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
| | - Iftikhar Ahmad
- Department of Physics, University of Malakand, Chakdara, 18800, Pakistan
| | - Bin Amin
- Department of Physics, Abbottabad Uniersity of Science and Technology, Abbottabad 22010, Pakistan.
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18
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Remarkable Enhancement of Eu–TiO2–GO Composite for Photodegradation of Indigo Carmine: A Design Method Based on Computational and Experimental Perspectives. Catal Letters 2020. [DOI: 10.1007/s10562-020-03386-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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19
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Manipulatable Interface Electric Field and Charge Transfer in a 2D/2D Heterojunction Photocatalyst via Oxygen Intercalation. Catalysts 2020. [DOI: 10.3390/catal10050469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Charge separation is the most important factor in determining the photocatalytic activity of a 2D/2D heterostructure. Despite the exclusive advantages of 2D/2D heterostructure semiconductor systems such as large surface/volume ratios, their use in photocatalysis is limited due to the low efficiency of charge separation and high recombination rates. As a remedy for the weak interlayer binding and low carrier transport efficiency in 2D/2D heterojunctioned semiconductors, we suggested an impurity intercalation method for the 2D/2D interface. PtS2/C3N4, as a prototype heterojunction material, was employed to investigate the effect of anion intercalation on the charge separation efficiency in a 2D/2D system using density functional theory. With oxygen intercalation at the PtS2/C3N4 interface, a reversed and stronger localized dipole moment and a built-in electric field were induced in the vertical direction of the PtS2/C3N4 interface. This theoretical work suggests that the anion intercalation method can be a way to control built-in electric fields and charge separation in designs of 2D/2D heterostructures that have high photocatalytic activity.
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20
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Tsoeu SE, Opoku F, Govender PP. Tuning the electronic, optical and structural properties of GaS/C2N van der Waals heterostructure for photovoltaic application: first-principle calculations. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2091-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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21
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Experimental and Computational Design of Highly Active Ce–ZrO2–GO Photocatalyst for Eosin Yellow Dye Degradation: The Role of Interface and Ce3+ Ion. Catal Letters 2019. [DOI: 10.1007/s10562-019-02729-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Zhang L, Liang Q, Yang P, Huang Y, Liu Y, Yang H, Yan J. ZIF-8 derived ZnO/Zn6Al2O9/Al2O3 nanocomposite with excellent photocatalytic performance under simulated sunlight irradiation. NEW J CHEM 2019. [DOI: 10.1039/c8nj04798g] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The ZIF-8 derived ZnO/Zn6Al2O9/Al2O3 nanocomposite exhibits an unprecedented photocatalytic degradation activity toward MO of high concentration.
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Affiliation(s)
- Li Zhang
- School of Chemistry and Chemical Engineering
- Hunan Institute of Science and Technology
- Yueyang
- P. R. China
| | - Qingman Liang
- School of Chemistry and Chemical Engineering
- Hunan Institute of Science and Technology
- Yueyang
- P. R. China
| | - Peng Yang
- School of Chemistry and Chemical Engineering
- Hunan Institute of Science and Technology
- Yueyang
- P. R. China
| | - Yang Huang
- School of Chemistry and Chemical Engineering
- Hunan Institute of Science and Technology
- Yueyang
- P. R. China
| | - Younian Liu
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - Haihua Yang
- School of Chemistry and Chemical Engineering
- Hunan Institute of Science and Technology
- Yueyang
- P. R. China
| | - Jianhui Yan
- School of Chemistry and Chemical Engineering
- Hunan Institute of Science and Technology
- Yueyang
- P. R. China
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23
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The effects of two-dimensional TiSe 2 on the thermoelectric, electronic and optical response of Yb 14MnSb 11/AlSb 9Yb 11 heterostructures - A theoretical study. J Mol Graph Model 2018; 86:179-191. [PMID: 30388692 DOI: 10.1016/j.jmgm.2018.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 11/23/2022]
Abstract
Two-dimensional TiSe2, with Yb14MnSb11 and AlSb9Yb11 thermoelectric materials, were used to generate heterostructures. The electronic and optical calculations were done using the Materials Studio 2018 modelling software package, employing the Cambridge Serial Total Energy Package code and using the generalised gradient approximation with Perdew-Burke-Ernzerhof exchange-correlation functionals. However, the electronic results obtained revealed a reduction in the calculated band gap and an increase in the slope of the density of state at the Femi level, as well as the energy bands of the generated heterostructures was reported. Partial density of states showed that various orbitals were present in the thermoelectric materials. The thermal transport and electronic properties are compared using the Boltzmann transport theory and Mott derived equations, which were expressed in the maximum attainable figure of merit. A variation in the electric potential of the layers is observed. The dielectric function is found to decrease in both thermoelectric layers generated and far more than the Yb14MnSb11-TiSe2 layer, which was more negative. The reduction in reflectivity of AlSb9Yb11TiSe2 layer and elevation of the Yb14MnSb11-TiSe2 layer is observed. Upon forming heterostructures with TiSe2, the conductivity reduced in the high frequency, due to the generated complex multicomponent compounds.
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24
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Du J, Tian Y, Li N, Zhang J, Zuo W. Enhanced antifouling performance of ZnS/GO/PVDF hybrid membrane by improving hydrophilicity and photocatalysis. POLYM ADVAN TECHNOL 2018. [DOI: 10.1002/pat.4472] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jinying Du
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment; Harbin Institute of Technology; Harbin 150090 China
| | - Yu Tian
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment; Harbin Institute of Technology; Harbin 150090 China
| | - Ning Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment; Harbin Institute of Technology; Harbin 150090 China
| | - Jun Zhang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment; Harbin Institute of Technology; Harbin 150090 China
| | - Wei Zuo
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment; Harbin Institute of Technology; Harbin 150090 China
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25
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Kiarii EM, Govender KK, Mamo MA, Govender PP. A first-principles study of half-Heusler intermetallic compound MgAgAs with 2D-TiC/2D-Mo2TiC composite material. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2337-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Kiarii EM, Govender KK, Mamo MA, Govender PP. DFT Study of Skutterudite CoSb 3
and In 0.2
Co 4
Sb 12
Thermoelectric Heterostructures with 2D-WSe 2. ChemistrySelect 2018. [DOI: 10.1002/slct.201801870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ephraim Muriithi Kiarii
- Department of Applied Chemistry; University of Johannesburg, P. O. Box 17011, Doornfontein Campus; 2028 Johannesburg South Africa
| | - Krishna Kuben Govender
- Department of Applied Chemistry; University of Johannesburg, P. O. Box 17011, Doornfontein Campus; 2028 Johannesburg South Africa
- Council for Scientific and Industrial Research; Meraka Institute; Center for High Performance Computing; 15 Lower Hope Road, Rosebank Cape Town 7700 South Africa
| | - Messai Adenew Mamo
- Department of Applied Chemistry; University of Johannesburg, P. O. Box 17011, Doornfontein Campus; 2028 Johannesburg South Africa
| | - Penny Poomani Govender
- Department of Applied Chemistry; University of Johannesburg, P. O. Box 17011, Doornfontein Campus; 2028 Johannesburg South Africa
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27
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Review on the criteria anticipated for the fabrication of highly efficient ZnO-based visible-light-driven photocatalysts. J IND ENG CHEM 2018. [DOI: 10.1016/j.jiec.2018.01.012] [Citation(s) in RCA: 525] [Impact Index Per Article: 87.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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28
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Fang H, Guo Y, Wu T, Liu Y. Biomimetic synthesis of urchin-like CuO/ZnO nanocomposites with excellent photocatalytic activity. NEW J CHEM 2018. [DOI: 10.1039/c8nj02052c] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly photocatalytic urchin-like CuO/ZnO nanocomposites were synthesized using glutamine as a growth regulator by a hydrothermal process with subsequent calcination.
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Affiliation(s)
- Hui Fang
- College of Chemistry, Key Laboratory of Biosensing and Molecular Recognition (Tianjin), and Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Nankai University
- Tianjin 300071
- China
| | - Yanxia Guo
- College of Chemistry, Key Laboratory of Biosensing and Molecular Recognition (Tianjin), and Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Nankai University
- Tianjin 300071
- China
| | - Tong Wu
- College of Chemistry, Key Laboratory of Biosensing and Molecular Recognition (Tianjin), and Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Nankai University
- Tianjin 300071
- China
| | - Yuping Liu
- College of Chemistry, Key Laboratory of Biosensing and Molecular Recognition (Tianjin), and Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Nankai University
- Tianjin 300071
- China
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29
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Opoku F, Kuben Govender K, van Sittert CGCE, Poomani Govender P. Charge transport, interfacial interactions and synergistic mechanisms in BiNbO 4/MWO 4 (M = Zn and Cd) heterostructures for hydrogen production: insights from a DFT+U study. Phys Chem Chem Phys 2017; 19:28401-28413. [PMID: 29034925 DOI: 10.1039/c7cp04440b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In the 21st century, the growing demand of global energy is one of the key challenges. The photocatalytic generation of hydrogen has attracted extensive attention to discuss the increasing global demand for sustainable and clean energy. However, hydrogen evolution reactions normally use the economically expensive rare noble metals and the processes remain a challenge. Herein, low-cost BiNbO4/MWO4(010) heterostructures are studied for the first time to check their suitability towards photocatalytic hydrogen production. A theoretical study with the aid of density functional theory (DFT) is used to investigate the synergistic effect, ionisation energy, electron affinities, charge transfer, electronic properties and the underlying mechanism for hydrogen generation of BiNbO4/MWO4(010) heterostructures. The experimental band gaps of bulk ZnWO4, CdWO4 and BiNbO4 are well reproduced using the DFT+U method. The calculated band edge position shows a type-II staggered band alignment and the charge transfer between BiNbO4 and MWO4 monolayers results in a large interfacial built-in potential, which will favour the separation of charge carriers in the heterostructures. The effective mass of the photoinduced holes is higher compared to the electrons, making the heterostructures useful in hydrogen production. The relatively low ionisation energy and electron affinity for the heterostructures compared to the monolayers make them ideal for photocatalysis applications due to their small energy barrier for the injection of electrons and creation of holes. The BiNbO4/MWO4(010) heterostructures are more suitable for photocatalytic hydrogen production due to their strong reducing power relative to the H+/H2O potential. This study sheds light on the less known BiNbO4/ZnWO4(010) heterostructures and the fully explored electronic and optical properties will pave way for future photocatalytic water splitting applications.
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Affiliation(s)
- Francis Opoku
- Department of Applied Chemistry, University of Johannesburg, P. O. Box 17011, Doornfontein Campus, Johannesburg, 2028, South Africa.
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