In-situ construction of InO/InS-CdInS Z-scheme heterojunction nanotubes for enhanced photocatalytic hydrogen production.

Semiconductor photocatalysis was considered as an ideal solution to energy shortages. Herein, a novel ternary InO/InS-CdInS (IOSC) nanotube (NTs) photocatalyst was successfully constructed via in situ growth of InS and CdInS nanosheets onto InO skeleton. It was used for the efficient and stable photo-production of hydrogen from water splitting. The rationally designed IOSC NTs displayed significantly enhanced photocatalytic H production under visible light irradiation (≥420 nm), with the highest H yield determined to be 2892 μmol·g, which is much higher than that of pristine InS and InO/InS (IOS) NTs. Cyclic testing has shown that the IOSC2 product remains stable after four cycles of repeated use. The enhanced photocatalytic activity was contributed by its tightly bound tube-nanosheets heterogeneous structure and superior light absorption. Photoelectrons transfer in IOSC2 follows a Z-scheme mechanism, which greatly facilitates its utilization of photogenerated electrons and prevents CdInS from undergoing photo-corrosion affecting material stability. This work demonstrates the key role of in situ growth in the interface design of ternary heterostructures.