CdS quantum dots-decorated InOOH: Facile synthesis and excellent photocatalytic activity under visible light

For the first time, CdS quantum dots (QDs)-decorated InOOH (CdS-In for short) was synthesized by a facile photodeposition method. The experiment results showed that CdS-In samples exhibited excellent activity and stability towards photocatalytic reduction of nitro aromatics. The conversion ratio of 4-nitroaniline (4-NA) over CdS-In sample that was prepared with photodeposition time of 120 min (CdS-In-120) reached up to 99.4% under visible light irradiation for 40 min, which was even higher than that achieved over commercial CdS (86.2%). Besides the significant enhancement of visible light absorption, quantum sized CdS were decorated evenly on the surface of InOOH, which was very beneficial for the high activity. Furthermore, the heterogeneous junction formed at the interface of CdS QDs and InOOH can significantly increase the separation efficiency of photogenerated charge carriers. Active species control experiment and electron spin resonance (ESR) technique have proved that photogenerated electrons are the main active species towards photocatalytic reduction of nitro aromatics. It is anticipated that our study would offer meaningful insights for exploring novel InOOH-based visible light photocatalysts towards efficient reduction of nitro aromatics.