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Koshevoy E, Gribov E, Polskikh D, Lyulyukin M, Solovyeva M, Cherepanova S, Kozlov D, Selishchev D. Photoelectrochemical Methods for the Determination of the Flat-Band Potential in Semiconducting Photocatalysts: A Comparison Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:13466-13480. [PMID: 37696112 DOI: 10.1021/acs.langmuir.3c01158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
In addition to the band gap of a semiconducting photocatalyst, its band edges are important because they play a crucial role in the analysis of charge transfer and possible pathways of the photocatalytic reaction. The Mott-Schottky method using electrochemical impedance spectroscopy is the most common experimental technique for the determination of the electron potential in photocatalysts. This method is well suited for large crystals, but in the case of nanocatalysts, when the thickness of the charged layer is comparable with the size of the nanocrystals, the capacitance of the Helmholtz layer can substantially affect the measured potential. A contact between the electrolyte and the substrate, used for deposition of the photocatalyst, also affects the impedance. Application of other photoelectrochemical methods may help to avoid concerns in the interpretation of impedance data and improve the reliability of measurements. In this study, we have successfully prepared five visible-light active photocatalysts (i.e., N-doped TiO2, WO3, Bi2WO6, CoO, and g-C3N4) and measured their flat-band potentials using four (photo)electrochemical methods. The potentials are compared for all methods and discussed regarding the type of semiconducting material and its properties. The effect of methanol as a sacrificial agent for the enhanced transfer of charge carriers is studied and discussed for each method.
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Affiliation(s)
- Evgeny Koshevoy
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
| | - Evgeny Gribov
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
| | - Danil Polskikh
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
| | - Mikhail Lyulyukin
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
| | - Maria Solovyeva
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
| | | | - Denis Kozlov
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
| | - Dmitry Selishchev
- Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090, Russia
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Samchenko SV, Kozlova IV, Korshunov AV, Zemskova OV, Dudareva MO. Synthesis and Evaluation of Properties of an Additive Based on Bismuth Titanates for Cement Systems. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6262. [PMID: 37763540 PMCID: PMC10532926 DOI: 10.3390/ma16186262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/07/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023]
Abstract
The development of modern building materials science involves the process of designing innovative materials that exhibit unique characteristics, such as energy efficiency, environmental friendliness, self-healing ability, and photocatalytic properties. This can be achieved by modifying cement with nano- and fine-dispersed additives that can give the material new properties. Such additives include a number of compounds based on the TiO2-Bi2O3 system. These compounds have photocatalytic activity in the near-UV and visible range of the spectrum, which can serve to create photocatalytic concretes. Here, the purpose of this scientific study was to synthesize compounds based on the TiO2-Bi2O3 system using two methods in order to identify the most optimal variant for creating a composite material and determine its properties. Within the framework of this article, two methods of obtaining a photocatalytically active additive based on the TiO2-Bi2O3 system are considered: the solid-state and citrate-based methods. The photocatalytic, mechanical and structural properties of composites containing the synthesized additive are investigated. In this study, it was found that for the creation of photocatalytic concretes, it is advisable to use cement compositions with a bismuth titanate content of 3-10 wt.%. of the cement content, regardless of the method of obtaining the additive. However, the most optimal composition is one containing 5 wt.% of the synthesized additive. It is noted that compositions containing 5% by weight of bismuth titanate demonstrate photocatalytic activity and also show an increase in strength on the first day of hardening by 10% for the solid-state method and 16% for the citrate method.
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Affiliation(s)
| | | | | | | | - Marina O. Dudareva
- Department of Building Materials, Moscow State University of Civil Engineering, 26, Yaroslavskoye Shosse, 129337 Moscow, Russia; (S.V.S.); (I.V.K.); (A.V.K.); (O.V.Z.)
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Selishcheva S, Sumina A, Gerasimov E, Selishchev D, Yakovlev V. High-Loaded Copper-Containing Sol-Gel Catalysts for Furfural Hydroconversion. Int J Mol Sci 2023; 24:ijms24087547. [PMID: 37108710 PMCID: PMC10142956 DOI: 10.3390/ijms24087547] [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: 03/14/2023] [Revised: 04/14/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
In this study, the high-loaded copper-containing catalysts modified with Fe and Al were successfully applied for the hydroconversion of furfural to furfuryl alcohol (FA) or 2-methylfuran (2-MF) in a batch reactor. The synthesized catalysts were studied using a set of characterization techniques to find the correlation between their activity and physicochemical properties. Fine Cu-containing particles distributed in an amorphous SiO2 matrix, which has a high surface area, provide the conversion of furfural to FA or 2-MF under exposure to high pressure of hydrogen. The modification of the mono-copper catalyst with Fe and Al increases its activity and selectivity in the target process. The reaction temperature strongly affects the selectivity of the formed products. At a H2 pressure of 5.0 MPa, the highest selectivity toward FA (98%) and 2-MF (76%) was achieved in the case of 35Cu13Fe1Al-SiO2 at the temperature of 100 °C and 250 °C, respectively.
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Affiliation(s)
| | - Anastasiya Sumina
- Boreskov Institute of Catalysis, Lavrentiev Ave. 5, Novosibirsk 630090, Russia
| | - Evgeny Gerasimov
- Boreskov Institute of Catalysis, Lavrentiev Ave. 5, Novosibirsk 630090, Russia
| | - Dmitry Selishchev
- Boreskov Institute of Catalysis, Lavrentiev Ave. 5, Novosibirsk 630090, Russia
| | - Vadim Yakovlev
- Boreskov Institute of Catalysis, Lavrentiev Ave. 5, Novosibirsk 630090, Russia
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Lyulyukin M, Kovalevskiy N, Bukhtiyarov A, Kozlov D, Selishchev D. Kinetic Aspects of Benzene Degradation over TiO2-N and Composite Fe/Bi2WO6/TiO2-N Photocatalysts under Irradiation with Visible Light. Int J Mol Sci 2023; 24:ijms24065693. [PMID: 36982767 PMCID: PMC10051460 DOI: 10.3390/ijms24065693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/07/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
In this study, composite materials based on nanocrystalline anatase TiO2 doped with nitrogen and bismuth tungstate are synthesized using a hydrothermal method. All samples are tested in the oxidation of volatile organic compounds under visible light to find the correlations between their physicochemical characteristics and photocatalytic activity. The kinetic aspects are studied both in batch and continuous-flow reactors, using ethanol and benzene as test compounds. The Bi2WO6/TiO2-N heterostructure enhanced with Fe species efficiently utilizes visible light in the blue region and exhibits much higher activity in the degradation of ethanol vapor than pristine TiO2-N. However, an increased activity of Fe/Bi2WO6/TiO2-N can have an adverse effect in the degradation of benzene vapor. A temporary deactivation of the photocatalyst can occur at a high concentration of benzene due to the fast accumulation of non-volatile intermediates on its surface. The formed intermediates suppress the adsorption of the initial benzene and substantially increase the time required for its complete removal from the gas phase. An increase in temperature up to 140 °C makes it possible to increase the rate of the overall oxidation process, and the use of the Fe/Bi2WO6/TiO2-N composite improves the selectivity of oxidation compared to pristine TiO2-N.
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Affiliation(s)
- Mikhail Lyulyukin
- Boreskov Institute of Catalysis, Novosibirsk 630090, Russia; (M.L.); (N.K.); (A.B.); (D.K.)
- Ecology and Nature Management Department, Aircraft Engineering Faculty, Novosibirsk State Technical University, Novosibirsk 630073, Russia
| | - Nikita Kovalevskiy
- Boreskov Institute of Catalysis, Novosibirsk 630090, Russia; (M.L.); (N.K.); (A.B.); (D.K.)
| | - Andrey Bukhtiyarov
- Boreskov Institute of Catalysis, Novosibirsk 630090, Russia; (M.L.); (N.K.); (A.B.); (D.K.)
| | - Denis Kozlov
- Boreskov Institute of Catalysis, Novosibirsk 630090, Russia; (M.L.); (N.K.); (A.B.); (D.K.)
| | - Dmitry Selishchev
- Boreskov Institute of Catalysis, Novosibirsk 630090, Russia; (M.L.); (N.K.); (A.B.); (D.K.)
- Correspondence: ; Tel.: +7-383-326-9429
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Zhang K, Tang X, Guo F, Xiao K, Zheng D, Ma Y, Zhao Q, Wang F, Yang B. Improved Dynamic Compressive and Electro-Thermal Properties of Hybrid Nanocomposite Visa Physical Modification. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:52. [PMID: 36615962 PMCID: PMC9824552 DOI: 10.3390/nano13010052] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
The current work studied the physical modification effects of non-covalent surfactant on the carbon-particle-filled nanocomposite. The selected surfactant named Triton™ X-100 was able to introduce the steric repelling force between the epoxy matrix and carbon fillers with the help of beneficial functional groups, improving their dispersibility and while maintaining the intrinsic conductivity of carbon particles. Subsequent results further demonstrated that the physically modified carbon nanotubes, together with graphene nanoplates, constructed an effective particulate network within the epoxy matrix, which simultaneously provided mechanical reinforcement and conductive improvement to the hybrid nanocomposite system. For example, the hybrid nanocomposite showed maximum enhancements of ~75.1% and ~82.5% for the quasi-static mode-I critical-stress-intensity factor and dynamic compressive strength, respectively, as compared to the neat epoxy counterpart. Additionally, the fine dispersion of modified fillers as a double-edged sword adversely influenced the electrical conductivity of the hybrid nanocomposite because of the decreased contact probability among particles. Even so, by adjusting the modified filler ratio, the conductivity of the hybrid nanocomposite went up to the maximum level of ~10-1-100 S/cm, endowing itself with excellent electro-thermal behavior.
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Affiliation(s)
- Kai Zhang
- School of Civil Engineering and Architecture, Suqian University, Suqian 223800, China
| | - Xiaojun Tang
- Beijing Spacecrafts, China Academy of Space Technology, Beijing 100094, China
| | - Fuzheng Guo
- College of Architectural Science and Engineering, Yangzhou University, Yangzhou 225127, China
| | - Kangli Xiao
- School of Civil Engineering and Architecture, Suqian University, Suqian 223800, China
| | - Dexin Zheng
- School of Civil Engineering and Architecture, Suqian University, Suqian 223800, China
| | - Yunsheng Ma
- Shandong Chambroad Holding Group Co., Ltd, Binzhou 256500, China
| | - Qingsong Zhao
- Shandong Chambroad Holding Group Co., Ltd, Binzhou 256500, China
| | - Fangxin Wang
- College of Architectural Science and Engineering, Yangzhou University, Yangzhou 225127, China
| | - Bin Yang
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092, China
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