SiC Substrate/Pt Nanoparticle/Graphene Nanosheet Composite Photocatalysts for Hydrogen Generation

• Published in: ACS applied nano materials 2024-04, Vol.7 (8), p.8958-8968
• Main Authors: Chen, Yun, Lai, Shengbao, Wu, Wenxuan, Zhong, Yiming, Guo, Yuanhui, Yu, Pengfei, Hou, Maoxiang, Liu, Huilong, Jiang, Lelun, Chen, Xin, Gao, Jian, Wong, Ching-Ping
• Format: Article
• Language: English
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.4c00443

As a widely known semiconductor material, SiC is expected to be used as a photocatalyst for hydrolysis to produce hydrogen. However, the fast recombination of light-induced carriers restricts its photocatalytic activity. To address this issue, SiC/Pt/graphene composite photocatalysts were prepared using a flash joule heating (FJH) method in seconds, and its efficiency of visible-light photoinduced hydrolysis for hydrogen production was significantly improved. The SiC/Pt/graphene photocatalyst achieved optimal performance with 2.8 wt % graphene and 4.0 wt % Pt loading. The highest hydrogen production rate was 2980 μmol·g–1·h–1, which is 175 times higher than that of pristine SiC, setting a record for SiC-based photocatalysts. The increased photocatalytic efficiency was due to the in situ formation of stable heterojunctions among β-SiC, graphene and noble metal platinum (Pt) during the FJH process. The TEM clearly observed the heterojunction interface, and the XPS confirmed a 16% increase in the Si–C bond content. The heterojunctions and Si–C bond can accelerate the transfer of photocatalytically produced carriers, inhibiting the fast recombination. Furthermore, the SiC/Pt/graphene composite photocatalysts maintained 80% of the original performance after three test cycles with a total duration of 12 h, showing remarkable stability. The proposed FJH method will provide more selections for preparing highly efficient and stable composite photocatalysts.