Development of a novel Ba2BiV3O11 photocatalyst with dual functions of both water oxidation and proton reduction performance

To overcome the limitation of photocatalysts with dual functionality of water oxidation and proton reduction, we proposed a novel bismuth-based Ba2BiV3O11 (BBVO) photocatalyst, which can simultaneously drive the proton reduction reaction under UV light and water oxidation reaction under visible light. After doping with sulfur through an in situ vulcanization strategy, the light absorption and charge separation efficiencies of the sulfur-doped BBVO were significantly improved, thus boosting its oxygen evolution activity (64 μmol h-1) by more than 16 times compared with independent BBVO. The experimental results demonstrate that BBVO can be employed as a very promising bismuth-based photocatalyst for solar energy conversion.

Boosting Photocatalytic Water Oxidation Over Bifunctional Rh0 -Rh3+ Sites

Photocatalytic water splitting provides an economically feasible way for converting solar energy into hydrogen. Great efforts have been devoted to developing efficient photocatalysts; however, the surface catalytic reactions, especially for the sluggish oxygen evolution reaction (OER), still remain a challenge, which limits the overall photocatalytic energy efficiency. Herein, we design a Rh_n cluster cocatalyst, with Rh⁰ -Rh³⁺ sites anchoring the Mo-doped BiVO₄ model photocatalytic system. The resultant photocatalyst enables a high visible-light photocatalytic oxygen production activity of 7.11 mmol g^-1  h^-1 and an apparent quantum efficiency of 29.37 % at 420 nm. The turnover frequency (TOF) achieves 416.73 h^-1 , which is 378 times higher than that of the photocatalyst only with Rh³⁺ species. Operando X-ray absorption characterization shows the OER process on the Rh⁰ -Rh³⁺ sites. The DFT calculations further illustrate a bifunctional OER mechanism over the Rh⁰ -Rh³⁺ sites, in which the oxygen intermediate attacks the Rh³⁺ sites with assistance of a hydrogen atom transfer to the Rh⁰ sites, thus breaking the scaling relationship of various oxygen intermediates.

Design, Fabrication, and Mechanism of Nitrogen-Doped Graphene-Based Photocatalyst

Solving energy and environmental problems through solar-driven photocatalysis is an attractive and challenging topic. Hence, various types of photocatalysts have been developed successively to address the demands of photocatalysis. Graphene-based materials have elicited considerable attention since the discovery of graphene. As a derivative of graphene, nitrogen-doped graphene (NG) particularly stands out. Nitrogen atoms can break the undifferentiated structure of graphene and open the bandgap while endowing graphene with an uneven electron density distribution. Therefore, NG retains nearly all the advantages of original graphene and is equipped with several novel properties, ensuring infinite possibilities for NG-based photocatalysis. This review introduces the atomic and band structures of NG, summarizes in situ and ex situ synthesis methods, highlights the mechanism and advantages of NG in photocatalysis, and outlines its applications in different photocatalysis directions (primarily hydrogen production, CO₂ reduction, pollutant degradation, and as photoactive ingredient). Lastly, the central challenges and possible improvements of NG-based photocatalysis in the future are presented. This study is expected to learn from the past and achieve progress toward the future for NG-based photocatalysis.

Immobilization of Metal-Organic Framework MIL-100(Fe) on the Surface of BiVO4: A New Platform for Enhanced Visible-Light-Driven Water Oxidation

The development of new dual functional photocatalysts is highly desirable for conversion and storage of solar energy. Herein, we first constructed hierarchical structure MIL-100(Fe)@BiVO₄ in situ growing MIL-100(Fe) nanoparticles (NPs) on the surface of decahedron BiVO₄ under mild hydrothermal conditions. The as-synthesized hybrid nanostructure is unambiguously determined using a series of characterization methods. These results demonstrate that the ultra-tiny MOF MIL-100(Fe) particles are immobilized on the surface of decahedron BiVO₄ and the composite exhibits a strong interaction between BiVO₄ and MIL-100(Fe). This hybrid material MIL-100(Fe)@BiVO₄ is employed as a photocatalyst for water oxidation reaction and demonstrates higher O₂ production activity in comparison with bare BiVO₄. The best performance obtained at the optimal mass percentage of MIL-100(Fe) (8.0 wt %) reaches 333.3 μmol h^-1 g^-1 of the O₂ evolution rate irradiated with visible light, which is almost 4.3 times higher than bare BiVO₄ (77.3 μmol h^-1 g^-1). The enhanced water oxidation performance is due to the more efficient interfacial electron-hole transfer between MIL-100(Fe) and BiVO₄, which is verified by the results of various photo-electrochemical characterizations. Moreover, the as-prepared composite MIL-100(Fe)@BiVO₄ also displays excellent stability for visible-light-driven water oxidation. This study affords a rational strategy for the controllable construction by loading metal-organic frameworks on a semiconductor surface, which is a good reference for other artificial photosystems.

Construction of a triple sequential junction for efficient separation of photogenerated charges in photocatalysis

A triple sequential junction providing a continuous charge separation and transfer channel was successfully fabricated by rational combining the anatase/rutile TiO₂ heterophase and rutile/rutile TiO₂ homophase junctions.

A stable iron-containing polyoxometalate coupled with semiconductor for efficient photocatalytic water oxidation under acidic condition

A homogeneous molecular catalyst, polyoxometalate (POM) Fe11, can act as a true cocatalyst for the efficient oxygen evolution reaction through the pH adjustment strategy when BiVO₄ is used as a light-harvesting material.