Cobalt phosphate co-catalysts and boron-doped ZnIn2S4 nanosheets for efficient photocatalytic hydrogen conversion

• Main Authors: Liu, Wen, Ye, Furong, Zhao, Yahao, Liu, Peng, Han, Changcun, Luoshan, Meng-Dai, Tian, Jiayi, Cheng, Zhengwang, Huang, Yizhong
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2024
• Subjects: Engineering; Boron doping; Cobalt phosphate
• Online Access: https://hdl.handle.net/10356/180762
• Institution: Nanyang Technological University

In the quest for effective photocatalysts for hydrogen production via photocatalytic water splitting, ZnIn2S4 has garnered considerable attention due to its high photocatalytic hydrogen evolution capability. In this study, boron-doped ZnIn2S4 was successfully synthesized via a hydrothermal method, with a small amount of cobalt phosphate (Co-Pi) decorated on its surface. The hydrogen evolution rate of boron-doped ZnIn2S4 was determined to be 5.2 mmol g−1 h−1, surpassing that of pure ZnIn2S4 by 1.68 times. Moreover, with the addition of Co-Pi to boron-doped ZnIn2S4, the hydrogen production rate escalated to 29.7 mmol g−1 h−1, which is 9.58 times higher compared to pure ZnIn2S4. UV–vis analysis revealed that boron doping introduced new energy levels into ZnIn2S4, effectively narrowing the bandgap and enhancing light absorption wavelength range. Furthermore, PL and XPS analyses indicate that Co-Pi effectively captures photogenerated holes (h+) in ZnIn2S4, retaining photogenerated electrons and overcoming the disadvantage of electron-hole pair recombination in ZnIn2S4. The doping and loading of Co-Pi as a cocatalyst ultimately contribute to enhancing hydrogen production efficiency, thereby significantly improving the photocatalytic hydrogen evolution capability of ZnIn2S4. This study provides a scalable idea for designing composite catalysts in which doping and co-catalysts work together.