Construction synergetic adsorption and activation surface via confined Cu/CuO and Ag nanoparticles on TiO for effective conversion of CO to CH.

High-performance photocatalysts for catalytic reduction of CO are largely impeded by inefficient charge separation and surface activity. Reasonable design and efficient collaboration of multiple active sites are important for attaining high reactivity and product selectivity. Herein, Cu-CuO and Ag nanoparticles are confined as dual sites for assisting CO photoreduction to CH on TiO.

Engineering Sub-Nanometer Hafnia-Based Ferroelectrics to Break the Scaling Relation for High-Efficiency Piezocatalytic Water Splitting.

Reversible control of ferroelectric polarization is essential to overcome the heterocatalytic kinetic limitation. This can be achieved by creating a surface with switchable electron density; however, owing to the rigidity of traditional ferroelectric oxides, achieving polarization reversal in piezocatalytic processes remains challenging. Herein, sub-nanometer-sized Hf Zr O (HZO) nanowires with a polymer-like flexibility are synthesized.

A Fully Conjugated Covalent Organic Framework with Oxidative and Reductive Sites for Photocatalytic Carbon Dioxide Reduction with Water.

Constructing a powerful photocatalytic system that can achieve the carbon dioxide (CO ) reduction half-reaction and the water (H O) oxidation half-reaction simultaneously is a very challenging but meaningful task. Herein, a porous material with a crystalline topological network, named viCOF-bpy-Re, was rationally synthesized by incorporating rhenium complexes as reductive sites and triazine ring structures as oxidative sites via robust -C=C- bond linkages. The charge-separation ability of viCOF-bpy-Re is promoted by low polarized π-bridges between rhenium complexes and triazine ring units, and the efficient charge-separation enables the photogenerated electron-hole pairs, followed by an intramolecular charge-transfer process, to form photogenerated electrons involved in CO reduction and photogenerated holes that participate in H O oxidation simultaneously.

Development of γ-AlO with oxygen vacancies induced by amorphous structures for photocatalytic reduction of CO.

Inducing amorphous components into AlO leads to elongation of the Al-O bond and the formation of oxygen vacancies, which makes AlO an independent photocatalyst for CO adsorption and reduction. The generation rate of CO can reach 36.5 μmol g h, which is 6.

Reverse construction of dominant/secondary facets in BiOBr photocatalysts for boosting electronic transfer.

In this paper, it is found that the preferential growth of secondary {117} facets of BiOBr into dominant facets would lead to higher photocatalytic activity, although the original main {213} facet has a stronger molecular oxygen adsorption ability, which illustrates that the charge separation efficiency induced by dominant/secondary facet control plays a more important role than that of O adsorptive performance in improving activity.

Promoting photocatalytic CO reduction to CH via a combined strategy of defects and tunable hydroxyl radicals.

A well-designed photocatalyst with excellent activity and selectivity is crucial for photocatalytic CO conversion and utilization. TiO is one of the most promising photocatalysts. However, its excessive surface oxidation potential and insufficient surface active sites inhibit its activity and photocatalytic CO reduction selectivity.

Strain-Engineered Nano-Ferroelectrics for High-Efficiency Piezocatalytic Overall Water Splitting.

Developing nano-ferroelectric materials with excellent piezoelectric performance for piezocatalysts used in water splitting is highly desired but also challenging, especially with respect to reaching large piezo-potentials that fully align with required redox levels. Herein, heteroepitaxial strain in BaTiO nanoparticles with a designed porous structure is successfully induced by engineering their surface reconstruction to dramatically enhance their piezoelectricity. The strain coherence can be maintained throughout the nanoparticle bulk, resulting in a significant increase of the BaTiO tetragonality and thus its piezoelectricity.

The simultaneous adsorption, activation and in situ reduction of carbon dioxide over Au-loading BiOCl with rich oxygen vacancies.

The main process of carbon dioxide (CO) photoreduction is that excited electrons are transported to surface active sites to reduce adsorbed CO molecules. Obviously, electron transfer to the active site is one of the key steps in this process. However, current catalysts for CO adsorption, activation, and electron reduction occur in different locations, which greatly reduce the efficiency of photocatalysis.

Recent advances in surface and interface design of photocatalysts for the degradation of volatile organic compounds.

Photocatalysis has attracted wide attention in eliminating volatile organic compounds (VOCs). This paper pays attention to the relationship between structure and performance of photocatalysts based on the fact that catalytic reactions arise on the surface of catalysts and the interface structure of photocatalysts plays key role in transfer efficiency of charges carriers. This review summarizes various surface/interface designs including unsaturated coordination such as oxygen vacancies, surface halogenations, and heterojunctions, homojunctions, facets, etc.

Construction of β-BiO/BiOCO heterojunction photocatalyst for deep understanding the importance of separation efficiency and valence band position.

Constructing heterojunctions would result in the change of valence band position, which is an important factor determining the oxidative ability of photo-induced holes, has received scant attention. In this paper, β-BiO/BiOCO composites with different ratios were obtained via ionic-liquid-assisted solvothermal and in-situ calcination processes. UV-vis DRS, Mott-Schottky test, and Kelvin probe measurement showed the change of band gaps of β-BiO and BiOCO before and after heterojunction formation.

Low-Temperature Methane Oxidation Triggered by Peroxide Radicals over Noble-Metal-Free MgO Catalyst.

Methane is a greenhouse gas that contributes to global warming. Hence, effectively removing the low concentration (<1000 ppm) of methane in the environment is an issue that deserves research in the field of catalysis. In this study, oxygen-magnesium bivacancies are simultaneously imbedded into MgO by designing an in situ reduction combustion atmosphere for oxygen release and substituting magnesium with carbon to induce the formation of magnesium vacancies.

Nano-Ferroelectric for High Efficiency Overall Water Splitting under Ultrasonic Vibration.

Piezocatalysis, converting mechanical vibration into chemical energy, has emerged as a promising candidate for water-splitting technology. However, the efficiency of the hydrogen production is quite limited. We herein report well-defined 10 nm BaTiO nanoparticles (NPs) characterized by a large electro-mechanical coefficient which induces a high piezoelectric effect.

Enhanced Schottky effect of a 2D-2D CoP/g-CN interface for boosting photocatalytic H evolution.

As emerging noble metal-free co-catalysts, transition metal phosphides have been employed to improve photocatalytic H2 production activity. Herein, the metallicity of CoP, as a representative phosphide, and the Schottky effect between CoP and g-C3N4 are confirmed via theoretical calculations. Then, a 2D/2D structure is designed to enlarge the Schottky effect between the interfaces, for which the apparent quantum efficiency of the photocatalytic H2 evolution is 2.

Synthesis of {111} Facet-Exposed MgO with Surface Oxygen Vacancies for Reactive Oxygen Species Generation in the Dark.

Seeking a simple and moderate route to generate reactive oxygen species (ROS) for antibiosis is of great interest and challenge. This work demonstrates that molecule transition and electron rearrangement processes can directly occur only through chemisorption interaction between the adsorbed O and high-energy {111} facet-exposed MgO with abundant surface oxygen vacancies (SOVs), hence producing singlet oxygen and superoxide anion radicals without light irradiation. These ROS were confirmed by electron paramagnetic resonance, in situ Raman, and scavenger experiments.

One-step synthesis, electronic structure, and photocatalytic activity of earth-abundant visible-light-driven FeAlO.

The development of inexpensive visible-light-driven photocatalysts is an important prerequisite for realizing the industrial application of photocatalysis technology. In this paper, an earth-abundant FeAlO photocatalyst is prepared via facile solution combustion synthesis. Density functional theory and the scanning Kelvin probe technique are employed to ascertain the positions of the energy bands and the Fermi level.

A Chelation Strategy for In-situ Constructing Surface Oxygen Vacancy on {001} Facets Exposed BiOBr Nanosheets.

Surface defect of nanomaterials is an important physical parameter which significantly influences their physical and chemical performances. In this work, high concentration of surface oxygen vancancies (SOVs) are successfully introduced on {001} facets exposed BiOBr nanosheets via a simple surface modification using polybasic carboxylic acids. The chelation interaction between carboxylic acid anions and Bi(3+) results in the weakness of Bi-O bond of BiOBr.

Introduction of CoCl2·6H2O into Co3O4 for enhancement of hydroxyl radicals and effective charge separation.

Porous sphere-like tricobalt tetraoxide (Co3O4)-cobalt chloride hydrate (CoCl2·6H2O, CCH) heterojunctions are obtained using a one-step facile solution combustion route. The heterostructure is confirmed by XRD, HRTEM, and XPS measurements. Their photocatalytic performances are evaluated by the degradation of methyl orange (MO) and the reduction removal of Cr(VI) ions under visible light irradiation.

Solution combustion synthesis of metal oxide nanomaterials for energy storage and conversion.

The design and synthesis of metal oxide nanomaterials is one of the key steps for achieving highly efficient energy conversion and storage on an industrial scale. Solution combustion synthesis (SCS) is a time- and energy-saving method as compared with other routes, especially for the preparation of complex oxides which can be easily adapted for scale-up applications. This review summarizes the synthesis of various metal oxide nanomaterials and their applications for energy conversion and storage, including lithium-ion batteries, supercapacitors, hydrogen and methane production, fuel cells and solar cells.

The synergy between Ti species and g-C3N4 by doping and hybridization for the enhancement of photocatalytic H2 evolution.

A Ti species modified g-C3N4 photocatalyst was synthesized via an in situ hydrothermal route and the subsequent low-temperature calcination. The hydrothermal process results in not only the fabrication of TiO2/g-C3N4 heterojunctions, but also the coordination between Ti species and g-C3N4, which are verified by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrical resistance test confirms that the coordination can improve the electrical conductivity of composites and can make the charge transfer easier.

Structure Modification Function of g-C3 N4 for Al2 O3 in the In Situ Hydrothermal Process for Enhanced Photocatalytic Activity.

Heterojunctions of g-C3 N4 /Al2 O3 (g-C3 N4 =graphitic carbon nitride) are constructed by an in situ one-pot hydrothermal route based on the development of photoactive γ-Al2 O3 semiconductor with a mesoporous structure and a high surface area (188 m(2) g(-1) ) acting as electron acceptor. A structure modification function of g-C3 N4 for Al2 O3 in the hydrothermal process is found, which can be attributed to the coordination between unoccupied orbitals of the Al ions and lone-pair electrons of the N atoms. The as-synthesized heterojunctions exhibit much higher photocatalytic activity than pure g-C3 N4 .

Construction of amorphous TiO₂/BiOBr heterojunctions via facets coupling for enhanced photocatalytic activity.

Facets coupled BiOBr with amorphous TiO2 composite photocatalysts are synthesized via an in situ direct growth approach under microwave irradiation. XRD, SEM and HRTEM characterizations indicate that the heterointerface between BiOBr and amorphous TiO2 occurs mainly on the {001} facets of BiOBr. BET and TEM verify that the heterojunctions possess higher specific surface areas and smaller amorphous TiO2 particle size than bare BiOBr and amorphous TiO2, exhibiting the inhibition function of BiOBr on the growth of TiO2 particles.

Ionic liquid self-combustion synthesis of BiOBr/Bi24O31Br10 heterojunctions with exceptional visible-light photocatalytic performances.

Heterostructured BiOBr/Bi24O31Br10 nanocomposites with surface oxygen vacancies are constructed by a facile in situ route of one-step self-combustion of ionic liquids. The compositions can be easily controlled by simply adjusting the fuel ratio of urea and 2-bromoethylamine hydrobromide (BTH). BTH serves not only as a fuel, but also as a complexing agent for ionic liquids and a reactant to supply the Br element.

Enhanced visible-light photocatalytic activity of active Al₂O₃/g-C₃N₄ heterojunctions synthesized via surface hydroxyl modification.

Novel Al2O3/g-C3N4 heterojunction photocatalysts were fabricated through ultrasonic dispersion method. Al2O3, obtained via solution combustion, contained amorphous ingredient with lots of defect sites and was used as active component for transferring photo-induced electrons of g-C3N4. G-C3N4 was grafted surface hydroxyl groups in the presence of ammonia aqueous solution to combine with Al2O3 possessing positive charges via hydrogen bond.