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A dual-cathode photoelectrocatalysis-electroenzymatic catalysis system by coupling BiVO4 photoanode with hemin/Cu and carbon cloth cathodes for degradation of tetracycline
摘要： When photoelectrocatalysis (PEC) couples with electroenzymatic catalysis (EEC), effective utilization of electrons from PEC process for yield of H2O2 plays an important role in the enzymatic catalysis. In the present work, we designed a novel dual-cathode PEC-EEC system for pollutant removal. In this system, BiVO4 photoanode was prepared by electrodeposition for visible light-driven PEC process while carbon cloth was used as the first cathode for electrogeneration of H2O2 and hemin/Cu prepared by electrophoretic deposition acted as the second cathode for enzymatic catalysis. The performances of the constructed dual-cathode PEC-EEC system were evaluated by decoloring Rhodamine B (RhB), which showed high decoloration percentage with acceptable stability and reusability. Further, the system was applied to degradation of tetracycline (TC), indicating that about 93.6% of TC was removed after 2-h treatment. A pathway for TC degradation in such a dual-cathode PEC-EEC system was proposed based on the intermediates determined by liquid chromatography coupled to mass spectrometry in tandem (LC-ESI-MS/MS).
关键词： BiVO4,Photoelectrocatalysis,Electroenzymatic catalysis,Tetracycline,Dual cathodes
更新于2025-09-23 15:23:52
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Enabling PIEZOpotential in PIEZOelectric Semiconductors for Enhanced Catalytic Activities
摘要： The past several decades have witnessed significant advances in synthesis and applications of PIEZOelectric semiconductors. They represent an important class of materials, including ferroelectric semiconductors. Notably, an intriguing combination of physical and chemical phenomena in PIEZOelectric semiconductors has triggered much interest in PIEZOcatalysis. Regardless of a short period of time for the development of PIEZOcatalysis, remarkable progress has been made in this field. Herein, this review summarizes recent development in PIEZOcatalysis enabled by PIEZOelectric semiconductors due to PIEZOpotential (i.e., piezopotential, pyropotential, and ferropotential)-induced built-in electric field. First, the PIEZOelectrics (i.e., piezoelectrics, pyroelectrics and ferroelectrics) are briefly introduced. Second, recent developments pertaining to PIEZOpotential-mediated catalysis are highlighted, including the introduction of representative PIEZOelectric semiconductors, their possible catalytic mechanisms, novel PIEZOelectric effects during catalytic process, and several appealing examples about PIEZOcatalysis. Finally, the challenges in the field and exciting opportunities to further improve the PIEZOcatalytic efficiency are discussed.
关键词： Ferroelectrics,Catalysis,Piezoelectrics,Pyroelectrics
更新于2025-09-23 15:23:52
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Treatment of industries wastewater using solar light
摘要： The degradation of eosin yellow dye using ZnO as a photo catalysts in a slurry reactor exposed to solar light was studied by this paper. The optimum values of different parameters versus catalyst concentration, catalyst type and initial concentration of the substrate affecting the degradation rate of eosin yellow dye were obtained by varying catalyst concentration (255–1255 ppm), and initial dye concentration (25–100 ppm). Color disappearance as well as substrates with the depletion of total organic carbon content was monitored.
关键词： eosin yellowish dye,Solar light,Photo catalysis,Zinc oxide
更新于2025-09-23 15:23:52
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Europium-Catalyzed Aerobic Oxidation of Alcohols to Aldehydes/Ketones and Photoluminescence Tracking
摘要： Europium is a lanthanide rare-earth metal and is known as a key element in luminophore development. Since europium has two relatively stable oxidation states, Eu2+ and Eu3+, which is exceptional among the various lanthanide elements, we have developed a europium-catalyzed aerobic oxidation with external oxidants utilizing the redox cycle of Eu2+/Eu3+. The reaction was performed under mild conditions with a wide substrate scope. The photoluminescence spectra clearly demonstrate the oxidation state changes that occur during the presented europium-catalyzed aerobic oxidation.
关键词： europium,oxidation,redox cycle,photoluminescence,homogeneous catalysis
更新于2025-09-23 15:22:29
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<i>N</i> -Arylphenothiazines as strong donors for photoredox catalysis – pushing the frontiers of nucleophilic addition of alcohols to alkenes
摘要： A new range of N-phenylphenothiazine derivatives was synthesized as potential photoredox catalysts to broaden the substrate scope for the nucleophilic addition of methanol to styrenes through photoredox catalysis. These N-phenylphenothiazines differ by their electron-donating and electron-withdrawing substituents at the phenyl group, covering both, σ and π-type groups, in order to modulate their absorbance and electrochemical characteristics. Among the synthesized compounds, alkylaminylated N-phenylphenothiazines were identified to be highly suitable for photoredox catalysis. The dialkylamino substituents of these N-phenylphenothiazines shift the estimated excited state reduction potential up to ?3.0 V (vs SCE). These highly reducing properties allow the addition of methanol to α-methylstyrene as less-activated substrate for this type of reaction. Without the help of an additive, the reaction conditions were optimized to achieve a quantitative yield for the Markovnikov-type addition product after 20 h of irradiation.
关键词： redox potential,photochemistry,addition,photoredox catalysis,phenothiazine
更新于2025-09-23 15:22:29
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Bulk Photodriven CO <sub/>2</sub> Conversion through TiO <sub/>2</sub> @Si(HIPE) Monolithic Macrocellular Foams
摘要： Operating photo-induced reactions exclusively on catalyst surfaces while not exploiting the full catalyst volume generates a major footprint penalty for the photocatalytic reactor and leads to an inefficient use of the catalytic material. Photonic investigations clearly show that the solid foams have a strongly multi-diffusive character, with photons being significantly trapped within the sample cores while addressing a photon mean free path lt = 20.1 ± 1.3 μm. This 3D process both greatly limits back-reactions and promotes outstanding selectivity toward methane (around 80%) generation, and even ethane (around 18%) through C-C coupling reaction, with residual carbon monoxide and dihydrogen contents (around 2%). Silica–titania TiO2@Si(HIPE) self-standing macrocellular catalysts lead to optimal efficient thicknesses up to 20 times those of powders, thereby enhancing the way for real 3D-photodriven catalytic processes above the millimeter scale and up to a 6 mm thickness. A rather simple Langmuir–Hinshelwood based kinetic model is proposed which highlights the strong dependence of photocatalytic reaction rates on light scattering and the crucial role on oxidation back-reactions. In addition, a strong correlation between light attenuation coefficient and photon mean free path and median pore aperture diameter is demonstrated, offering thus a tool for photocatalytic behavior prediction.
关键词： heterogeneous catalysis,CO2 photoreduction,sol–gel process,porous materials,integrative chemistry
更新于2025-09-23 15:22:29
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Synthesis of a novel visible light responsive <i>γ</i> -Fe2O3/SiO2/C-TiO2 magnetic nanocomposite for water treatment
摘要： This work investigates the preparation of a magnetically recoverable photocatalytic nanocomposite of maghemite nanoparticles coated with silica and carbon doped titanium dioxide. The novel nanocomposite boasts the advantages of efficient photocatalytic degradation of organic pollutants in water and ease of recovery of the fine particles after water treatment. The photocatalytic nanocomposite was successfully synthesized through a stepwise approach via co-precipitation and sol-gel methods. Characterisation by FTIR, XRD, TEM and EDS substantiated the existence of the intended structure of the nanocomposite and the particles were found to be in the size range of 15–22 nm with a quasi-spherical shape. BET surface area analysis revealed an average surface area of 55.20 m2/g which is higher than that of commercial TiO2 (Degussa P25, 50.00 m2/g) and an average pore diameter of 8.36 nm. A 5 ppm methylene blue solution was degraded with an efficiency of 96.8% after 3 h of solar irradiation, which was 19.7% greater than using the same photo-catalyst under strict UV light irradiation. Photo-catalysis using these nanoparticles was observed to be very effective. The prepared novel visible light active nanocomposite has great potential for incorporation into water treatment systems because it exhibits good stability and magnetism as well as high photocatalytic efficiency.
关键词： methylene blue,titanium dioxide,water treatment,maghemite,photo-catalysis,magnetic nanocomposite
更新于2025-09-23 15:22:29
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Two-dimensional-related catalytic materials for solar-driven conversion of CO <sub/>x</sub> into valuable chemical feedstocks
摘要： The discovery of improved chemical processes for CO and CO2 hydrogenation to valuable hydrocarbon fuels and alcohols is of paramount importance for the chemical industry. Such technologies have the potential to reduce anthropogenic CO2 emissions by adding value to a waste stream, whilst also reducing our consumption of fossil fuels. Current thermal catalytic technologies available for CO and CO2 hydrogenation are demanding in terms of energy input. Various alternative technologies are now being developed for COx hydrogenation, with solar-driven processes over two-dimensional (2D) and 2D-related composite materials being particularly attractive due to the abundance of solar energy on Earth and also the high selectivity of defect-engineered 2D materials towards specific valuable products under very mild reaction conditions. This review showcases recent advances in the solar-driven COx reduction to hydrocarbons over 2D-based materials. Optimization of 2D catalyst performance demands interdisciplinary research that embraces catalyst electronic structure manipulation and morphology control, surface/interface engineering, reactor engineering and density functional theory modelling studies. Through improved understanding of the structure–performance relationships in 2D-related catalysts which is achievable through the application of modern in situ characterization techniques, practical photo/photothermal/photoelectrochemical technologies for CO and CO2 reduction to high-valuable products such as olefins could be realized in the not-too-distant future.
关键词： hydrocarbons,feedstocks,two-dimensional materials,solar-driven conversion,catalysis,COx reduction
更新于2025-09-23 15:22:29
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Anti-Markovnikov Hydroazidation of Alkenes by Visible Light Photoredox Catalysis
摘要： The anti-Markovnikov hydroazidation of alkenes has been accomplished using [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 as photocatalyst and trimethylsilyl azide as azidating agent. The reactions were greatly facilitated by water, whose beneficial effect can be attributed to its participation in the reaction as the hydrogen donor, as indicated by deuterium isotope experiments. The reactions can be effected under solvent free conditions in the presence of water. 4-Dimethylaminopyridine also exhibited a beneficial effect on the reactions. The present method enabled hydroazidation of several types of unactivated alkenes with good yield and high regionselectivity.
关键词： hydroazidation,water,trimethylsilyl azide,radical reactions,photoredox catalysis
更新于2025-09-23 15:22:29
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Calculations of adsorption energies, coadsorptions, and diffusion barriers of H atoms, and the H <sub/>2</sub> formation on a nanographene surface (coronene)
摘要： Adsorption and diffusion of ortho, meta, and para cis hydrogen dimers, on central and edge rings of coronene (nanographene), were studied by using the DFT-D method, considering different multiplicities. Calculated values of adsorption energy, coadsorption energy, diffusion barriers, and reaction barriers for the H2 formation (Langmuir-Hinshelwood (LH) mechanism) were evaluated for ortho and para locations. The adsorption of an H atom increases the adsorption energy of another hydrogen (coadsorption). The most stable dimers are those where an H is adsorbed on hydrogenated-edge sites. Dimers with multiplicity M = 1, with H separated by an odd number of bonds, have higher coadsorption energies (higher diffusion barriers) than those where the separation is by an even number. The H2 formation is more feasible on edge-edge and edge-center sites; however, on ortho hydrogenated-edge sites, it is not energetically favored. For M = 3, H2 formation is not observed because desorption of H occurs.
关键词： H2 formation,interstellar media catalysis,nanographene,coronene,hydrogen diffusion
更新于2025-09-23 15:22:29