Charge Transfer Mechanism in Type II WO/CuO Heterostructure.

In this study, we explore the charge transfer mechanism between WO and CuO in heterostructured WO/CuO electrodes and in a WO||CuO tandem photoelectrochemical cell. The physical-chemical characterizations of the individual WO and CuO electrodes and the heterostructured WO/CuO electrode by XRD, XPS, and SEM methods confirm the successful formation of the target systems. The results of photoelectrochemical studies infer that in both the heterostructured WO/CuO electrode and WO||CuO tandem photoelectrochemical cell, the major mechanism of charge transfer between WO and CuO is a realization of the Z-scheme.

Perovskite CsCuClxBr3- x Microcrystals: Band Structure, Photochemical Stability, and Photocatalytic Properties.

Although Pb-based metal halide perovskites (MHPs) have excellent photoelectric characteristics, their toxicity remains a limiting factor for their widespread application. In the paper, a series of CsCuClxBr3-x (x = 1, 2, 3) MHP microcrystals were developed and their hydrogen evolution performance in ethanol and HX (X = Cl, Br) was also studied. Among them, CsCuCl3 microcrystals exhibit high hydrogen evolution performance in both HX and ethanol, attributed to their longest average lifetime and suitable band structure.

Pivotal Impact Factors in Photocatalytic Reduction of CO to Value-Added C and C Products.

Over the past decades, CO greenhouse emission has been considerably increased, causing global warming and climate change. Indeed, converting CO into valuable chemicals and fuels is a desired option to resolve issues caused by its continuous emission into the atmosphere. Nevertheless, CO conversion has been hampered by the ultrahigh dissociation energy of C=O bonds, which makes it thermodynamically and kinetically challenging.

Laser flash photolysis study of NbO/g-CN heterostructures as efficient photocatalyst for molecular H evolution.

Improvements of visible light activity, slow recombination rate, stability, and efficiency are major challenges facing photocatalyst technologies today. Utilizing heterostructures of g-CN (bandgap ∼2.7eV) with NbO (bandgap ∼3.

Tuning the Microstructures of ZnO To Enhance Photocatalytic NO Removal Performances.

Effective removal of kinetically inert dilute nitrogen oxide (NO, ppb) without NO emission is still a challenging topic in environmental pollution control. One effective approach to reducing the harm of NO is the construction of photocatalysts with diversified microstructures and atomic arrangements that could promote adsorption, activation, and complete removal of NO without yielding secondary pollution. Herein, microstructure regulations of ZnO photocatalysts were attempted by altering the reaction temperature and alkalinity in a unique ionic liquid-based solid-state synthesis and further investigated for the removal of dilute NO upon light irradiation.

Simultaneous S-scheme promoted Ag@AgVO/g-CN/CeVO heterojunction with enhanced charge separation and photo redox ability towards solar photocatalysis.

Photocatalytic removal of toxic contaminants is one of the emerging techniques for water remediation, but it suffers from low redox ability, charge recombination and poor light harvesting efficiency. The present work reports a simultaneous S-scheme promoted by CeVO/g-CN/Ag@AgVO. The formation of the S-scheme mechanism enhanced the generation of photogenerated carriers and also improved the redox ability of the electrons and holes in the reduction and oxidation photocatalysts.

Investigation of the Photocatalytic Hydrogen Production of Semiconductor Nanocrystal-Based Hydrogels.

Destabilization of a ligand-stabilized semiconductor nanocrystal solution with an oxidizing agent can lead to a macroscopic highly porous self-supporting nanocrystal network entitled hydrogel, with good accessibility to the surface. The previously reported charge carrier delocalization beyond a single nanocrystal building block in such gels can extend the charge carrier mobility and make a photocatalytic reaction more probable. The synthesis of ligand-stabilized nanocrystals with specific physicochemical properties is possible, thanks to the advances in colloid chemistry made in the last decades.

Boosting photocatalytic performances of lamellar BiVOby constructing S-scheme heterojunctions with AgBr for efficient charge transfer.

Successful construction of heterojunction can improve the utilization efficiency of solar light by broadening the absorption range, facilitating charge-carrier separation, promoting carrier transportation and influencing surface-interface reaction. Herein, visible-light-driven AgBr was deposited on the surface of lamellar BiVOwhich was prepared by a facile hydrothermal process to improve charge carrier separation, and subsequent photocatalytic effectiveness. The catalyst with an optimal AgBr/BiVOratio exhibited a superbly enhanced photocatalytic decolorization ability (about 6.

Design and synthesis of TiO/C nanosheets with a directional cascade carrier transfer.

Directed transfer of carriers, akin to excited charges in photosynthesis, in semiconductors by structural design is challenging. Here, TiO nanosheets with interlayered sp carbon and titanium vacancies are obtained by low-temperature controlled oxidation calcination. The directed transfer of carriers from the excited position to Ti-vacancies to interlayered carbon is investigated and proven to greatly increase the charge transport efficiency.

Photocatalytic H production and degradation of aqueous 2-chlorophenol over B/N-graphene-coated Cu/TiO: A DFT, experimental and mechanistic investigation.

Energy and environmental challenges are global concerns that scientists are interested in alleviating. It is on this premise that we prepared boron/nitrogen graphene-coated Cu/TiO (B/N-graphene-coated Cu/TiO) photocatalyst of varying B:N ratios with dual functionality of H production and 2-Chlorophenol (2-CP) degradation. In-situ coating of Cu with B/N-graphene is achieved via solvothermal synthesis and calcination under an inert atmosphere.

Effect of CuO Substrate on Photoinduced Hydrophilicity of TiO and ZnO Nanocoatings.

The effect of a CuO substrate on the photoinduced alteration of the hydrophilicity of TiO and ZnO surfaces was studied. It was demonstrated that the formation of heterostructures CuO/TiO and CuO/ZnO strongly changed the direction of the photoinduced alteration of surface hydrophilicity: while both TiO and ZnO demonstrate surface transition to superhydrophilic state under UV irradiation and no significant alteration of the surface hydrophilicity under visible light irradiation, the formation of CuO/TiO and CuO/ZnO heterostructures resulted in photoinduced decay of the surface hydrophilicity caused by both UV and visible light irradiation. All observed photoinduced changes of the surface hydrophilicity were compared and analyzed in terms of photoinduced alteration of the surface free energy and its polar and dispersive components.

Isotope Effects in Photocatalysis: An Underexplored Issue.

In order to improve the performance of well-established photocatalysts and to develop new potential photocatalyst materials, an understanding of the underlying mechanisms of photocatalytic reactions is of the utmost importance. An often neglected method for studying the mechanism is the investigation of isotope effects. Although just a few studies related to isotope effects exist, it has been shown to be a powerful tool for exploring mechanisms of photocatalytic processes.

Visible light-driven novel BiTiO/CaTiO composite photocatalyst with enhanced photocatalytic activity towards NO removal.

Photocatalysis is regarded as a promising technology for removal of nitrogen oxide (NO), however, the low photocatalytic efficiencies under visible light irradiation and the deactivation of the photocatalyst are as yet the significant issues that should be addressed. In this work, visible-light-driven BiTiO/CaTiO heterojunction composites were synthesized by a facile in-situ hydrothermal method. The BiTiO/CaTiO composites displayed superior visible light photocatalytic activity than pure CaTiO and pure BiTiO in the removal of NO at the 600 ppb level in air.

Soft and hard templates assisted synthesis mesoporous CuO/g-CN heterostructures for highly enhanced and accelerated Hg(II) photoreduction under visible light.

Herein, triblock copolymer surfactant (F127) and mesoporous silica (MCM-41) as soft and hard templates were employed to synthesize of mesoporous CuO/g-CN heterostructures with large surface areas for Hg(II) photoreduction in existence of formic acid as a holes sacrificial. TEM image for mesoporous CuO/g-CN indicated that CuO NPs are homogeneously distributed with spherical shape in particle size ~5 nm onto the surface of g-CN. Mesoporous 2%CuO/g-CN heterostructure was achieved a high Hg(II) photoreduction rate of 628.

Nitrogen/Carbon-Coated Zero-Valent Copper as Highly Efficient Co-catalysts for TiO Applied in Photocatalytic and Photoelectrocatalytic Hydrogen Production.

Zero-valent copper (Cu) is a promising co-catalyst in semiconductor-based photocatalysis as it is inexpensive and exhibits electronic properties similar to those of Ag and Au. However, its practical application in photocatalytic hydrogen production is limited by its susceptibility to oxidation, forming less active Cu species. Herein, we have carried out encapsulation of Cu nanoparticles with N-graphitic carbon layers (14.

Pb-Free CsBiI Perovskite as a Visible-Light-Active Photocatalyst for Organic Pollutant Degradation.

In our work, we employed CsBiI as a visible-light-active photocatalyst, synthesized with a low-temperature solvothermal method. The morphological and structural properties of the as-prepared perovskite were investigated, and the results were compared to previous studies to confirm its nature and the quality of the synthesis procedure. Transient absorption spectroscopy was applied in order to investigate the generation and lifetime of photogenerated charge carriers, revealing their formation after visible light excitation.

Ag(I) ions working as a hole-transfer mediator in photoelectrocatalytic water oxidation on WO film.

Ag(I) is commonly employed as an electron scavenger to promote water oxidation. In addition to its straightforward role as an electron acceptor, Ag(I) can also capture holes to generate the high-valent silver species. Herein, we demonstrate photoelectrocatalytic (PEC) water oxidation and concurrent dioxygen evolution by the silver redox cycle where Ag(I) acts as a hole-transfer mediator.

UV/Vis Light Induced Degradation of Oxytetracycline Hydrochloride Mediated byCo-TiO Nanoparticles.

Pharmaceuticals, especially antibiotics, constitute an important group of aquatic contaminants given their environmental impact. Specifically, tetracycline antibiotics (TCs) are produced in great amounts for the treatment of bacterial infections in both human and veterinary medicine. Several studies have shown that, among all antibiotics, oxytetracycline hydrochloride (OTC HCl) is one of the most frequently detected TCs in soil and surface water.

Unraveling the photocatalytic properties of TiO/WO mixed oxides.

TiO2/WO3 heterojunctions are one of the most investigated systems for photocatalytic applications. However, distinct behavior can be found in the literature depending on the pollutant to be degraded and the photocatalyst preparation conditions. Some authors reported improved photocatalytic activities in relation to TiO2, while others a deleterious effect.

Influence of the preparation conditions on the morphology and photocatalytic performance Pt-modified hexaniobate composites.

The preparation of lamellar nanostructures through exfoliation of stacked niobates is an interesting approach to the development of photocatalysts for energy conversion and environmental remediation. These materials exhibit a rich surface chemistry and several nanocomposites can be produced through intercalation or impregnation of suitable precursors. In this work, the influence of the physico-chemical preparation conditions on the photocatalytic activity of Pt-hexaniobate nanocomposites was investigated aiming at the establishment of the main factors that control their photoreactivities.

Ultrathin-Layer Structure of BiOI Microspheres Decorated on N-Doped Biochar With Efficient Photocatalytic Activity.

Bismuth oxyiodide (BiOI) is among the most potential photocatalysts due to its photocatalytic activity under visible light irradiation. However, the photoinduced carrier separation efficiency has limited the BiOI photocatalytic activity. Herein, we utilized the direct carbonation of sapless cattail grass to obtain N-doped hierarchical structure cattail-based carbon (NCC).

Two-Dimensional Layered Zinc Silicate Nanosheets with Excellent Photocatalytic Performance for Organic Pollutant Degradation and CO Conversion.

Two-dimensional (2D) photocatalysts are highly attractive for their great potential in environmental remediation and energy conversion. Herein, we report a novel layered zinc silicate (LZS) photocatalyst synthesized by a liquid-phase epitaxial growth route using silica derived from vermiculite, a layered silicate clay mineral, as both the lattice-matched substrate and Si source. The epitaxial growth of LZS is limited in the 2D directions, thus generating the vermiculite-type crystal structure and ultrathin nanosheet morphology with thicknesses of 8-15 nm and a lateral size of about 200 nm.

Photodegradation of Microcystin-LR Using Visible Light-Activated C/N-co-Modified Mesoporous TiO₂ Photocatalyst.

Microcystin-LR (MC-LR), a potent hepatotoxin produced by the cyanobacteria, is of increasing concern worldwide because of severe and persistent impacts on humans and animals by inhalation and consumption of contaminated waters and food. In this work, MC-LR was removed completely from aqueous solution using visible-light-active C/N-co-modified mesoporous anatase/brookite TiO₂ photocatalyst. The co-modified TiO₂ nanoparticles were synthesized by a one-pot hydrothermal process, and then calcined at different temperatures (300, 400, and 500 °C).