1D/2D constructed Bi2S3/Bi2O2CO3 direct Z-Scheme heterojunction: A versatile photocatalytic material for boosted photodegradation, photoreduction and photoelectrochemical detection of water-based contaminants.

Photoelectrochemical (PEC) water splitting has been regarded as a promising technology for sustainable hydrogen production. The development of efficient photoelectrode materials is the key to improve the solar-to-hydrogen (STH) conversion efficiency towards practical application. Bismuth vanadate (BiVO4) is one of the most promising photoanode materials with the advantages of visible light absorption, good chemical stability, nontoxic feature, and low cost. However, the PEC performance of BiVO4 photoanodes is limited by the relatively short hole diffusion length and poor electron transport properties. The recent rapid development of vacancy defect engineering has significantly improved the PEC performance of BiVO4. In this review article, the fundamental properties of BiVO4 are presented, followed by an overview of the methods for creating different kinds of vacancy defects in BiVO4 photoanodes. Then, the roles of vacancy defects in tuning the electronic structure, promoting charge separation, and increasing surface photoreaction kinetics of BiVO4 photoanodes are critically discussed. Finally, the major challenges and some encouraging perspectives for future research on vacancy defect engineering of BiVO4 photoanodes are presented, providing guidelines for the design of efficient BiVO4 photoanodes for solar fuel production.

Vacancy defect engineering of BiVO4 photoanodes for photoelectrochemical water splitting

Magnetic visible-light activated photocatalyst ZnFe2O4/BiVO4/g-C3N4 for decomposition of antibiotic lomefloxacin: Photocatalytic mechanism, degradation pathway, and toxicity assessment.

Bismuth vanadate is a promising photoanode for solar-to-fuel photocatalytic applications, and it has been extensively studied in recent years. However, the microscopic mechanism underlying the obse...

Role of Point Defects in Enhancing the Conductivity of BiVO4

For the global energy demand and climate change challenges, seeking renewable, sustainable energy sources is of great significance. Photoelectrochemical (PEC) water splitting is one of the promising technologies for converting intermittent solar energy into storable hydrogen energy, to tackle these issues. As the core component in a PEC system, photoelectrodes have been modified by various strategies including nanostructuring, facet-engineering, elemental doping, and heterostructured engineering. Apart from these techniques, numerous effective post-synthetic treatments have also been used to facilely and powerfully boost the physicochemical properties of photoelectrodes, for the enhancement of their PEC performance. Among them, a number of post-treatments can selectively influence photoelectrode surface and subsurface areas, altering surface states that play crucial roles in the hydrogen/oxygen evolution reaction. In virtue of such post-treatments, we summarize recently reported post-synthetic treatments for enhanced PEC applications. Post-treatment methods are classified into three sections: chemical treatments, electrochemical and irradiation-based treatments, and post-annealing treatments. In the end, a summary and outlook section regarding the utilization of post-treatments for PEC applications have been provided. This review can provide inspiration for further studies about post-treatments, not only in the PEC water splitting field, but also in other aspects, such as electrolysis.

Recent Progress on Post-Synthetic Treatments of Photoelectrodes for Photoelectrochemical Water Splitting

Plasma-implanted Ti-doped hematite photoanodes with enhanced photoelectrochemical water oxidation performance

Bismuth vanadate (BiVO4) is one of the highly promising photoanodes for photoelectrochemical (PEC) water splitting but suffers from severe carrier recombination and undesirable charge transfer at the semiconductor–electrolyte interface. Herein, we employ an effective surface-engineered sulfite treatment to improve the PEC performance of BiVO4 without illumination. This post-synthetic treatment on BiVO4 photoanodes can substantially enhance the interfacial charge transfer efficiency because of decreased charge carrier recombination arising from both surface oxygen vacancies (Ovac) and surface disordered layers. The as-prepared BiVO4 exhibits a photocurrent density of 2.2 mA cm−2 at 1.23 V vs. the reversible hydrogen electrode (RHE) under 1-sun illumination, which is 1.7-times higher than that of pristine BiVO4. By coating the amorphous FeOOH cocatalyst, the photocurrent density can be further improved to 2.8 mA cm−2. We demonstrate that the chemical reaction employing a reducing agent with a mild reduction activity can controllably alter the surface states of BiVO4 photoanodes, providing a facile, efficient, and low-cost strategy to achieve high-performance photoelectrodes.

Chemical reduction-induced surface oxygen vacancies of BiVO4 photoanodes with enhanced photoelectrochemical performance

Suppressing photoinduced charge recombination at the BiVO4||NiOOH junction by sandwiching an oxygen vacancy layer for efficient photoelectrochemical water oxidation.

Yong Peng

Papers

Plasma-implanted Ti-doped hematite photoanodes with enhanced photoelectrochemical water oxidation performance

Chemical reduction-induced surface oxygen vacancies of BiVO4 photoanodes with enhanced photoelectrochemical performance

Suppressing photoinduced charge recombination at the BiVO4||NiOOH junction by sandwiching an oxygen vacancy layer for efficient photoelectrochemical water oxidation.

Recent Progress on Post-Synthetic Treatments of Photoelectrodes for Photoelectrochemical Water Splitting