Article
Chemistry, Physical
Zhenzi Li, Jiaxing Wu, Lijun Liao, Xiangyi He, Baoxia Huang, Shiyu Zhang, Yuxiu Wei, Shijie Wang, Wei Zhou
Summary: The study utilizes surface defect engineering to enhance the photoelectrochemical activity of γ-Fe2O3 nanorod photoanodes. The as-prepared one-dimensional defective nanorods show superior visible-light absorption capacity and excellent photoelectrochemical performance.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Physical
Hao Zhang, Peng Li, Haochen Zhou, Jiamin Xu, Qianfan Jiang, Joseph H. L. Hadden, Yanying Wang, Mengnan Wang, Shengli Chen, Fang Xie, Jason Riley
Summary: In this study, a dual-functional catalyst based on hematite was developed for both EC and PEC water oxidation in alkaline media. The catalyst exhibited excellent activity and stability on both EC and PEC, and showed superior electrocatalytic performance for OER. The addition of gold nanoparticles on the hematite improved the adsorption strength of oxygen-containing intermediates and increased the OER activity.
Article
Chemistry, Multidisciplinary
Justine Sageka Nyarige, Alexander T. Paradzah, Tjaart P. J. Kruger, Mmantsae Diale
Summary: Zinc-doped, silver-doped, and zinc/silver codoped hematite nanostructures were synthesized and used as photoanodes for watersplitting. The codoped sample showed the highest photocurrent density and free carrier density, as well as low impedance. The nanostructures exhibited uniformly distributed grains and absorption in the visible region.
Article
Chemistry, Physical
Yong Peng, Qingdong Ruan, Chun Ho Lam, Fanxu Meng, Chung-Yu Guan, Shella Permatasari Santoso, Xingli Zou, Edward T. Yu, Paul K. Chu, Hsien-Yi Hsu
Summary: The nanoporous titanium-doped alpha-Fe2O3 thin films fabricated using a hydrothermal reaction and energetic plasma ion implantation exhibit significantly enhanced photoelectrochemical water oxidation performance, with approximately 1.6-fold increases in photocurrent compared to pristine Fe2O3, attributed to improved charge carrier transport induced by Ti doping. This work provides new insights into surface engineering of photo-responsive semiconductors for emerging hydrogen technologies.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Electrical & Electronic
Changhai Liu, Tingting Zhang, Dengxiaojiang Zhao, Chao Zhang, Guofu Ou, Haozhe Jin, Zhidong Chen
Summary: A novel strategy of constructing an amorphous nickel-borate thin layer on Ti-doped α-Fe2O3 photoanode was developed to significantly enhance the water oxidation kinetics and improve the photocurrent density, showing potential for practical photoelectrochemical applications.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Chemistry, Multidisciplinary
Tianying Liu, Wei Li, David Z. Wang, Tongtong Luo, Muchun Fei, Dongyoon Shin, Matthias M. Waegele, Dunwei Wang
Summary: Solar water oxidation is a crucial step in artificial photosynthesis, and its success relies on the accumulation of charges at the active site. Little is known about the impact of catalyst density on the reaction rate. This study investigates the interplay between catalyst density and surface hole concentration and reveals the unexpected benefits of low-density catalyst loading in facilitating forward charge transfer.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Cheng Lu, Duo Zhang, Zhenyu Wu, Xiaoquan Zhao, Kun Feng, Gaoteng Zhang, Shuao Wang, Zhenhui Kang, Jun Zhong
Summary: In this study, a hetero phase of & beta;-Fe2O3 was introduced in & alpha;-Fe2O3 to optimize the internal structure, which significantly enhanced the charge extraction and transport, and suppressed the electron-hole recombination. The resulting hematite-based photoanodes exhibited high initial photocurrent and excellent stability, making them a promising candidate for practical solar water splitting.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Chuang Li, Dan Wang, Jiangli Gu, Yichun Liu, Xintong Zhang
Summary: The study demonstrates that O-2 plasma treatment is an effective method to reduce surface oxygen vacancies on semiconductor photoanodes, leading to improved photoelectrochemical water oxidation performance and reduced surface recombination, resulting in significantly increased photocurrent density.
Article
Multidisciplinary Sciences
Abdur Rauf, Muhammad Adil, Shabeer Ahmad Mian, Gul Rahman, Ejaz Ahmed, Zia Mohy Ud Din, Wei Qun
Summary: In this study, the thermodynamic stability, photoconductivity, and optical properties of rhodium-doped hematite were investigated using density functional theory. The results showed that the doped material is more thermodynamically stable, with a narrowed bandgap enhancing optical absorption and photoconductivity. Incorporating rhodium in hematite induced a redshift in optical properties, enabling a broad spectrum absorption.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
Hyo-Jin Ahn, Ki-Yong Yoon, Mingi Sung, Hyeonjin Yoo, Hyungju Ahn, Byoung Hoon Lee, Junghoon Lee, Ji-Hyun Jang
Summary: This study explored the potential of using diketopyrrolopyrrole (DPP)based pi-conjugated polymers as hole transport layer material in heteroatom-doped hematite (Ti-Fe2O3/Ge-Fe2O3) photoanodes for efficient photoelectrochemical water splitting. The siloxane-modified pi-conjugated polymer (P-Si) exhibited high carrier mobility and stability, leading to a 1.8-fold increase in photocurrent density and improved stability compared to Ge-doped porous Fe2O3 (Ge-PH). This study demonstrated the successful use of inherently unstable pi-conjugated polymers as a hole extracting/transport medium for efficient and stable water splitting.
ACS ENERGY LETTERS
(2023)
Article
Energy & Fuels
Li Fu, Hongmei Yu, Yimin Lin, Wanqing Fang
Summary: The alpha-Fe2O3-H@CoO-H/Ti foil synthesized by a two-step calcination process is used as a photoanode for photoelectrochemical water splitting, with a nanowheat-like structure and surface defects favorable for light absorption and charge carrier separation. Characterization studies show that the photoanode exhibits high photocurrent densities at 1.23V and 1.6V versus reversible hydrogen electrode. Electrochemical impedance spectroscopy reveals decreased resistance and improved charge carrier behavior at the interface. Various factors including morphology, residual catalyst, and surface defects play important roles in enhancing the efficiency of photoelectrochemical water splitting.
Article
Chemistry, Physical
Mauricio A. Melo, Igor M. Brito, Joao V. S. B. Mello, Pamela S. M. Rocha, Isabela A. A. Bessa, Braulio S. Archanjo, Fabio S. Miranda, Ricardo J. Cassella, Celia M. Ronconi
Summary: Producing solar fuels through semiconductor-based photocatalytic water splitting is a promising solution for global adoption of renewable energy sources. This study introduces a simple method for preparing nanostructured hematite and niobium-doped hematite nanoparticles, which can be assembled into thin films for use as photoanodes in photoelectrochemical cells. The optimization of film composition and thickness significantly improves the photocurrent and enhances the efficiency of water splitting, making these materials more economically competitive.
Review
Chemistry, Physical
Zhiliang Wang, Lianzhou Wang
Summary: Oxygen vacancies play a crucial role in the optimization of photoelectrodes for PEC water splitting, affecting light absorption, charge separation, and surface reaction kinetics. Although the presence of oxygen vacancies may increase recombination, recent research has shown their beneficial impact on PEC performance, contrary to previous understanding. A comprehensive analysis of oxygen vacancies in metal oxide photoelectrodes is essential for achieving high efficiency in PEC.
Article
Chemistry, Physical
Samar M. Fawzy, Ghada E. Khedr, Nageh K. Allam
Summary: Density functional theory was used to investigate the effect of Te-Ti doping on TiO2. Te doping resulted in band gap narrowing and the formation of mid-gap states, reducing the birefringence of TiO2 in the UV region. Te-Ti combined with native oxygen vacancies and hydrogen interstitials showed potential as catalysts for photo-electrochemical water-splitting. The catalytic activity for oxygen evolution reaction was highest in Te-Ti + O-v material, while for hydrogen evolution reaction, Te-Ti + H-i material performed the best.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Ceramics
Niusha Mouchani, Amin Yourdkhani, Reza Poursalehi
Summary: Zr-doped hematite thin films were prepared using a liquid phase deposition method and their PEC properties were enhanced by flame treatment. The flame treatment increased the photocurrent density and activated the donor doping through the formation of oxygen vacancies. The study suggests that butane reduced flame treatment is an effective method to improve the PEC properties of hematite thin films.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Physical
Ainur Zhussupbekova, Kuanysh Zhussupbekov, Ruggero Verre, David Caffrey, Kyle Shiel, Igor V. Shvets, Karsten Fleischer
Summary: Oxide semiconductors have the potential to surpass currently employed semiconductors, but the insufficient development of p-type oxides is a major obstacle. This study introduces an optical sensing method for monitoring oxide film growth during spray pyrolysis. By extracting the changes in refractive index in real time, the thermal decomposition processes can be understood and synthesis conditions can be optimized.
CHEMISTRY OF MATERIALS
(2022)
Article
Electrochemistry
Andrew Selkirk, Salih Zeki Bas, Cian Cummins, Emre Aslan, Imren Hatay Patir, Ainur Zhussupbekova, Nadezda Prochukhan, Dipu Borah, Aislan Paiva, Mustafa Ozmen, Michael A. Morris
Summary: In this study, a multifunctional, nanostructured tungsten oxide catalytic device was developed using block copolymer templating for both the oxygen evolution reaction (OER) and epinephrine (EP) detection. The device exhibited excellent performance and strong anti-interference abilities against interfering compounds. The results of this study demonstrate the significant potential of block copolymer templating for developing low-cost, high-performance electrocatalytic devices in nanomanufacturing.
Article
Environmental Sciences
Yang Bai, Zhongzhong Wang, Piet N. L. Lens, Ainur Zhussupbekova, Igor V. Shvets, Zhuangsong Huang, Jun Ma, Guangxue Wu, Xinmin Zhan
Summary: Autotrophic denitrification using inorganic compounds as electron donors has many advantages in wastewater treatment. However, the effects of tetracycline (TC) stress on autotrophic denitrification have been rarely reported. This study investigated the effects of TC on autotrophic denitrification with thiosulfate and iron sulfide as electron donors. The results showed that TC slowed down the nitrate removal rate when thiosulfate was used as the electron donor, but had no significant effect when iron sulfide was used. The FeS-based autotrophic denitrification process is a promising technology for the treatment of wastewater containing emerging contaminants and nutrients.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Physics, Applied
J. Conway, M. Snelgrove, P. Yadav, K. Shiel, R. Lundy, A. Selkirk, R. O'Connor, M. A. Morris, M. M. Turner, S. Daniels
Summary: This study investigates the conversion of metal salt infiltrated polymer films to metal oxide films using oxygen plasma treatments in an asymmetrical capacitively coupled plasma system. The impact of radio frequency power, gas pressure, and process time on plasma composition and resulting metal oxide films is examined. Various measurement techniques are used to monitor the plasma and analyze the sample surfaces. Gas pressure and RF power are found to significantly influence ion energy and the ratio of atomic oxygen to molecular ions in the plasma, which affect the formation of the surface layer.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Brian Walls, Oisin Murtagh, Sergey I. Bozhko, Andrei Ionov, Andrey A. Mazilkin, Daragh Mullarkey, Ainur Zhussupbekova, Dmitry A. Shulyatev, Kuanysh Zhussupbekov, Nikolai Andreev, Nataliya Tabachkova, Igor V. Shvets
Summary: Vanadium dioxide (VO2), a strongly correlated electron material, has attracted significant attention in metal-oxide electronics due to its metal-to-insulator transition near room temperature. Vacuum annealing of V2O5(010) single crystal results in Wadsley phases and VO2. Macroscopic voltage-current measurements reveal resistive switching at extremely low voltages due to Joule heating. High-resolution transmission electron microscopy measurements show a complex structural relationship between V2O5, VO2, and V6O13 crystallites.
Article
Materials Science, Multidisciplinary
S. O'Donnell, M. Snelgrove, K. Shiel, C. Weiland, G. Hughes, J. Woicik, D. O'Neill, F. Jose, C. McFeely, R. O'Connor
Summary: This study utilizes ALD and photoemission characterization techniques to analyze the growth and properties of cobalt nitride, providing important insights for optimizing plasma-assisted ALD processes.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Chemistry, Multidisciplinary
Lucia Hughes, Ahin Roy, Clive Downing, Michelle P. P. Browne, Ainur Zhussupbekova, Igor V. V. Shvets, Valeria Nicolosi
Summary: By utilizing atomic-scale imaging and spectroscopic techniques, a structure-property correlation for the oxygen reduction reaction (ORR) in barium manganese oxide (BaMnO3) is established, with the presence of Mn3+ on the rod surface contributing to the electrocatalytic activity of the material.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Electrochemistry
Sean Ryan, Michelle P. Browne, Ainur Zhussupbekova, Dahnan Spurling, Lorcan McKeown, Danielle Douglas-Henry, Lucy Prendeville, Sebastien Vaesen, Wolfgang Schmitt, Igor Shvets, Valeria Nicolosi
Summary: Due to the energy crisis faced by this generation, the development of green energy and its storage, particularly the use of supercapacitors, has become a focus of attention. Single walled carbon nanotubes (SWCNT) were identified as a promising material for supercapacitor electrodes, however, their electrical properties are damaged when exposed to anodic potentials in sulphate-based electrolytes. In this study, we propose a strategy to expand the voltage window of SWCNTs by adding tin (II) oxide (SnO), which protects the SWCNTs from oxidation and improves long-term cycling stability. We also demonstrate the advantage of the expanded voltage window in an asymmetric device using MXene, achieving a capacity retention of 90% after 7,500 cycles at 10 A g(-1).
ELECTROCHIMICA ACTA
(2023)
Article
Physics, Applied
S. O'Donnell, D. O'Neill, K. Shiel, M. Snelgrove, F. Jose, C. McFeely, R. O'Connor
Summary: The production of hydrogen fuel through sunlight-driven water splitting has great potential for storing solar energy in a clean and scalable chemical state. Silicon is a suitable material for the photoelectrochemical (PEC) water-splitting photoanode, but it needs additional protective layers to overcome corrosion. Nickel oxide (NiO) is one effective protective material, and this study focuses on the deposition and characterization of NiO and Ni-metal protective films.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Environmental
Yang Bai, Shun Wang, Ainur Zhussupbekova, Igor V. Shvets, Po-Heng Lee, Xinmin Zhan
Summary: Iron sulfides-based autotrophic denitrification (IAD) is a cost-effective and low sludge production technology for nitrate and phosphate removal from low C:N ratio wastewater. However, its slow kinetics compared to other sulfur-based autotrophic denitrification (SAD) processes limits its application. This study constructed an iron sulfur autotrophic denitrification (ISAD) biofilter with co-electron-donors (FeS and S0) and achieved superior total nitrogen and phosphate removals at short hydraulic retention times (HRTs) through the interaction between FeS and S0. Metagenomic analysis revealed the presence of nitrate-dependent iron-oxidizing (NDFO) bacteria, sulfur-oxidizing bacteria (SOB), and dissimilatory nitrate reduction to ammonia (DNRA) bacteria, supporting stable nitrate reduction.
Article
Nanoscience & Nanotechnology
Ardak Ainabayev, Daragh Mullarkey, Brian Walls, David Caffrey, Kuanysh Zhussupbekov, Ainur Zhussupbekova, Cansu Ilhan, Aitkazy Kaisha, Pranab Biswas, Alexander Tikhonov, Oisin Murtagh, Igor Shvets
Summary: The ability of VO2 to undergo semiconductor-to-metal phase transition (SMT) upon heating makes it suitable for uncooled bolometers. However, characteristics such as high transition temperature, sharpness, hysteresis, and high resistivity limit its performance. In this study, high-quality epitaxial ultrathin film VO2 was grown on c-plane Al2O3 by pulsed laser deposition. The control of grain size and oxygen vacancy concentration allowed the adjustment of SMT parameters, and the high density of grain boundaries suppressed thermal hysteresis. This approach provides a simpler and more efficient method for practical bolometer applications.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Irina Parkhomenko, Liudmila Vlasukova, Fadei Komarov, Nataliya Kovalchuk, Sergey Demidovich, Ainur Zhussupbekova, Kuanysh Zhussupbekov, Igor V. Shvets, Oleg Milchanin, Dmitry Zhigulin, Ivan Romanov
Summary: Silicon nitride, silicon oxide, and silicon oxynitride thin films were deposited on Si substrate using inductively coupled plasma chemical vapor deposition and annealed in Ar environment at 1100℃ for 3 minutes. The composition and structural properties of the films were investigated, and it was found that annealing led to thickness decrease and structural transformation. Nanocrystalline phases of Si and Si3N4 were observed in the annealed silicon nitride film. The calculated optical parameters were shown to reflect the structural peculiarities of the as-deposited and annealed films.
Article
Materials Science, Multidisciplinary
Samuel Berman, Ainur Zhussupbekova, Brian Walls, Killian Walshe, Sergei I. Bozhko, Andrei Ionov, David D. O'Regan, Igor Shvets, Kuanysh Zhussupbekov
Summary: In this study, the highly stable niobium oxide overlayer of Nb(110) with a distinctive nanocrystal structure was investigated by scanning tunneling microscopy (STM). Ab initio density functional theory (DFT) calculations revealed that a subtle reconstruction in the surface niobium atoms resulted in rows of fourfold coordinated oxygen, which were found to be responsible for the nanocrystal pattern observed in STM. The two chemical states of oxygen observed in core-level x-ray photoelectron spectroscopy (XPS) were attributed to the threefold and fourfold oxygens. Moreover, excellent agreement was found between the DFT calculated electronic structure and the scanning tunneling spectroscopy and valence XPS measurements.
Article
Chemistry, Multidisciplinary
Anara Molkenova, Lazzat Serik, Alina Ramazanova, Kamila Zhumanova, Bakyt Duisenbayeva, Ainur Zhussupbekova, Kuanysh Zhussupbekov, Igor V. Shvets, Ki Su Kim, Dong-Wook Han, Timur Sh. Atabaev
Summary: Metal-doped carbon dots, specifically terbium-doped CDs, have been studied as a potential contrast agent for computed tomography. Physicochemical analysis showed that the prepared Tb-CDs have small sizes, high terbium concentration, and good colloidal stability. Preliminary tests also indicated that Tb-CDs have negligible cytotoxicity and demonstrate high X-ray absorption performance.
Article
Materials Science, Multidisciplinary
Kuanysh Zhussupbekov, Lida Ansari, Kenan Elibol, Ainur Zhussupbekova, Jani Kotakoski, Igor V. Shvets, Georg S. Duesberg, Paul K. Hurley, Niall Mcevoy, Cormac O'Coileain, Farzan Gity
Summary: The properties and performance of platinum diselenide (PtSe2) films, synthesized by thermally assisted conversion, were investigated using various spectroscopic and microscopic methods. The presence of distinct edge states was observed, and the origin of these states was investigated using theoretical tools and atomistic modeling. The results showed that the edges of polycrystalline films can have semiconducting or semimetallic properties depending on their configuration. The study also explored the potential of using a monomaterial heterojunction based field-effect transistor, which demonstrated excellent performance due to the critical role of the edge states in facilitating carrier transport.
APPLIED MATERIALS TODAY
(2023)
