Flower-like NiCo2S4 decorated by CdIn2S4 nanoparticles for enhanced photocatalytic hydrogen evolution activity

Abstract

Background

The rapid complexation of photogenerated carriers in sulphides has emerged as a significant challenge in optimizing photocatalytic hydrogen production.

Methods

Flower-like NiCo₂S₄/CdIn₂S₄ (NCSCIS) microspheres were synthesized by hydrothermal treatment and in situ deposition method in this study. CdIn₂S₄ nanoparticles were uniformly decorated on the surface of flower-like NiCo₂S₄ microspheres assembled from nanotubes, forming multi-heterojunctions.

Significant finding

Benefited from the heterostructure, their visible-light photocatalytic activity for hydrogen evolution was notably enhanced compared with that of single CdIn₂S₄. Among them, the hydrogen evolution rate of optimal 15NCSCIS heterojunction composite is 43 times that of independent CdIn₂S₄. Demonstrated by various optical and electrochemical experiments, the heterojunction significantly promoted the separation of photoinduced electron-hole pairs, improved the hydrogen evolution activity, strengthened the visible-light absorption and reduced the electron transfer resistance, thus resulting in the enhancement of photocatalytic activity. The photocatalytic mechanism of Schottky junction was proposed based on their energy band potentials. This work would provide new insights into the design of inexpensive heterojunction photocatalysts with high photocatalytic activity.