Zhiwei Chen

Bio: Zhiwei Chen is an academic researcher from South Central University for Nationalities. The author has contributed to research in topics: Adsorption & Bismuth selenide. The author has an hindex of 3, co-authored 3 publications receiving 30 citations.

Crucial Effect of Halogen on the Photocatalytic Hydrogen Evolution for Bi19X3S27 (X = Cl, Br) Nanomaterials

Abstract: Halogen has a significant effect on the photocatalytic performance of bismuth chalcohalide (Bi19X3S27, X = Cl, Br), which is a class of unique material that holds a bright future and is used in hyd...

(Invited) Contributions of Phase, Sulfur Vacancies, and Edges to the Hydrogen Evolution Reaction Catalytic Activity of Porous Molybdenum Disulfide Nanosheets

Abstract: Molybdenum disulfide (MoS2) is a promising nonprecious catalyst for the hydrogen evolution reaction (HER) that has been extensively studied due to its excellent performance, but the lack of understanding of the factors that impact its catalytic activity hinders further design and enhancement of MoS2-based electrocatalysts. Here, by using novel porous (holey) metallic 1T phase MoS2 nanosheets synthesized by a liquid-ammonia-assisted lithiation route, we systematically investigated the contributions of crystal structure (phase), edges, and sulfur vacancies (S-vacancies) to the catalytic activity toward HER from five representative MoS2 nanosheet samples, including 2H and 1T phase, porous 2H and 1T phase, and sulfur-compensated porous 2H phase. Superior HER catalytic activity was achieved in the porous 1T phase MoS2 nanosheets that have even more edges and S-vacancies than conventional 1T phase MoS2. A comparative study revealed that the phase serves as the key role in determining the HER performance, as 1T phase MoS2 always outperforms the corresponding 2H phase MoS2 samples, and that both edges and S-vacancies also contribute significantly to the catalytic activity in porous MoS2 samples. Then, using combined defect characterization techniques of electron spin resonance spectroscopy and positron annihilation lifetime spectroscopy to quantify the S-vacancies, the contributions of each factor were individually elucidated. This study presents new insights and opens up new avenues for designing electrocatalysts based on MoS2 or other layered materials with enhanced HER performance.

Bismuth-based photocatalysts for solar energy conversion

Abstract: Semiconductor photocatalysis is a promising technology for solar fuel production and environmental remediation. However, the solar energy conversion efficiency is far from satisfactory, which restricts its practical application. The development of semiconductor materials is crucial to promote the solar energy conversion efficiency in photocatalytic systems. Owing to the Bi 6s and O 2p hybrid orbitals in the valence band, most of the bismuth-based photocatalysts possess a narrow bandgap for visible light utilization, which has attracted increasing attention. In the past few years, a rich family of bismuth-based photocatalysts have been developed, which are yet to be comprehensively reviewed. In this review article, the recent progress of bismuth-based nanomaterials for photocatalysis including pollutant degradation, water splitting, CO2 reduction, N2 fixation, and organic synthesis is critically reviewed. In particular, promising strategies for promoting the photocatalytic activity of each material system is discussed and the key challenges and prospects of bismuth-based materials for photocatalysis are presented, which are believed to promote the development of this important research field.

Interfacial Engineering of Bi19Br3S27 Nanowires Promotes Metallic Photocatalytic CO2 Reduction Activity under Near-Infrared Light Irradiation.

Abstract: Developing highly efficient photocatalysts to utilize solar radiation for converting CO2 into solar fuels is of great importance for energy sustainability and carbon neutralization. Herein, through an alkali-etching-introduced interface reconstruction strategy, a nanowire photocatalyst denoted as V-Bi19Br3S27, with rich Br and S dual-vacancies and surface Bi-O bonding introduced significant near-infrared (NIR) light response, has been developed. The as-obtained V-Bi19Br3S27 nanowires exhibit a highly efficient metallic photocatalytic reduction property for converting CO2 into CH3OH when excited solely under NIR light irradiation. Free of any cocatalyst and sacrificial agent, metallic defective V-Bi19Br3S27 shows 2.3-fold higher CH3OH generation than Bi19Br3S27 nanowires. The detailed interfacial structure evolution and reaction mechanism have been carefully illustrated down to the atomic scale. This work provides a unique interfacial engineering strategy for developing high-performance sulfur-based NIR photocatalysts for photon reducing CO2 into alcohol for achieving high-value solar fuel chemicals, which paves the way for efficiently using the solar radiation energy extending to the NIR range to achieve the carbon neutralization goal.