Enhanced photocatalytic hydrogen evolution by piezoelectric effects based on MoSe2/Se-decorated CdS nanowire edge-on heterostructure.

Se decorated CdS nanowires with few-layer MoSe 2 nanosheets are fabricated for efficient H 2 production. The piezoelectric field of MoSe 2 nanosheets promotes the separation of free charges. Compared with the photocatalysis, the piezo-photocatalysis yields a superior H 2 evolution rate of 59.1 mmol/h g−1 (124.9% that of photocatalysis). [Display omitted] The build-in electric field by the construction of heterojunction is one of the most promising strategies to suppress the recombination of photogenerated carriers. Here, we reported a piezo-photocatalytic system composed of Se-decorated CdS nanowires and few-layered edge-on MoSe 2 nanosheets for efficient H 2 generation by two-pot hydrothermal synthesis. The few-layered MoSe 2 exposed abundant edge sites for hydrogen evolution reaction (HER). The activity of 20-MoSe 2 /CdS 0.95 Se 0.05 (20-MS/CSS, with 20 mol% of MoSe 2 loading) nanocomposite casted a remarkable photocatalytic HER performance, with a rate of 47.3 mmol h−1 g−1. Moreover, MoSe 2 nanosheets deformed to generate the piezoelectric polarization field under magnetic stirring, which rendered efficient separation of photogenerated carriers, resulting in a piezo-photocatalytic synergistic effect. As a result, the HER of 20-MS/CSS at 900 rpm for piezo-photocatalysis was 59.1 mmol h−1 g−1, which was 1.25 times that of 20-MS/CSS for photocatalysis. Meanwhile, the photoelectrochemical measurements further visualized the piezo-photoelectric synergy. This study exposes a new way for utilizing mechanical energy to improve photocatalytic performance, and achieving high piezo-photocatalysis. [ABSTRACT FROM AUTHOR]