In-situ construction of tubular core–shell noble-metal-free CMT@TiO2/ZnIn2S4 S-scheme heterojunction for superior photothermal-photocatalytic hydrogen evolution
摘要
Developing efficient and stable photocatalysts for hydrogen generation still remains a huge challenge. Herein, we adopted Cynanchum fibers as a carbon source and substrate to construct a ternary hollow core–shell carbon microtubes@TiO2/ZnIn2S4 (denoted as CMT@TiO2/ZnIn2S4) for photothermal-assisted photocatalytic hydrogen evolution (PHE). For the catalyst system, ZnIn2S4 is the main visible light absorber, TiO2 is introduced to form a heterojunction with ZnIn2S4 to facilitate the separation of photogenerated carriers, and hollow CMT derived from Cynanchum fibers serves as a conductive scaffold and a photothermal core to elevate the surface temperature of the localized reaction system. Benefiting from the rationally designed multicomponents and microstructures, the photocatalyst proposed enhanced PHE activity of 9.71 mmol·g−1·h−1, which was 30.3, 2.7 and 1.5 times higher than those of binary CMT@TiO2, pristine ZnIn2S4 and TiO2/ZnIn2S4 composite, respectively. The outperformed PHE activity of CMT@TiO2/ZnIn2S4 could be ascribed to the synergy of the formation of intimate heterointerface, the CMT-induced photothermal effect and the hierarchical core–shell architecture. This work provides a promising approach for constructing efficient and durable photocatalysts for H2 evolution.
Graphical abstract