Fabrication of novel noble-metal-free ZnIn2S4/WC Schottky junction heterojunction photocatalyst: Efficient charge separation, increased active sites and low hydrogen production overpotential for boosting visible-light H2 evolution

• Published in: Journal of alloys and compounds Vol. 901; p. 163709
• Main Authors: Ma, Xiaohui, Li, Wenjun, Ren, Chaojun, Li, Hongda, Li, Xinyang, Dong, Mei, Gao, Ying, Wang, Tianyu, Zhou, Hualei, Li, Yanyan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.04.2022; Elsevier BV
• Subjects: Catalytic activity; Heterojunctions; Hydrogen; Hydrogen evolution; Hydrogen production; Hydrogen production overpotential; Nanoparticles; Noble metal-free; Noble metals; Photocatalysis; Photocatalysts; Photocatalytic hydrogen production; Reaction mechanisms; Schottky junction heterojunction; Separation; ZnIn2S4/WC; ZnIn2S4/WC; Hydrogen production overpotential; Photocatalytic hydrogen production; Noble metal-free; Schottky junction heterojunction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.163709

•A novel noble metal-free ZnIn2S4/WC heterojunction was synthesized based on the combination of semiconductor and metal-like.•The optimal ZnIn2S4/WC photocatalysts have a lower overpotential for hydrogen evolution than pristine ZnIn2S4.•The H2 production ability of the optimal ZnIn2S4/WC was about 9.2 times than that of ZnIn2S4-1% Pt.•A feasible Schottky junction reaction mechanism of intensive photocatalytic activity was discussed. [Display omitted] Herein, we report the synthesis of ZnIn2S4 nanoparticles on bulk WC by a facile hydrothermal process to construct novel and highly efficient noble metal-free Schottky junction heterojunction photocatalysts. Morphology characterization revealed that the ZnIn2S4 nanoparticles were deposited on the surface of the WC. Meanwhile, the combination of the ZnIn2S4 and the metal-like WC formed the Schottky energy barrier, which greatly promoted the migration and separation of photo-generated carriers. Especially, the optimal ZnIn2S4/WC photocatalysts have a lower overpotential for hydrogen evolution (−0.35 V) than pristine ZnIn2S4 (−0.49 V). The hydrogen production ability of the optimal ZnIn2S4/WC photocatalyst (2400.3 μmol·h−1·g−1) was approximately 9.2 times higher than that of ZnIn2S4-1% Pt (260.1 μmol·h−1·g−1). Photocatalytic experiments demonstrated that metal-like WC plays an important role in replacing precious metal to increase the active site of ZnIn2S4. Moreover, a feasible Schottky junction reaction mechanism of intensive photocatalytic activity was discussed. This study proves that it is a very fascinating strategy to combine the advantages of ZnIn2S4 and metal-like to construct Schottky heterojunction for photocatalytic hydrogen production.