S-scheme heterojunction of hollow corncob-like ZnIn2S4/LaFeO3 for water splitting and tetracycline degradation

Abstract

Reasonable design of heterojunction photocatalysts with high-quality interfacial coupling is an effective way to improve the photocatalytic activity of semiconductors. Herein, we successfully decorated Zinc indium sulfide (ZnIn2S4, ZIS) on perovskite Lanthanum ferrite (LaFeO3, LFO) with more active sites by a pre-hydrothermal combined post-calcination method, and constructed S-scheme heterojunction photocatalyst with a unique hollow corncob-like morphology for efficient photocatalytic hydrogen production and tetracycline (TC) degradation. When the mass ratio of LFO is 35% and 15%, the ZIS/LFO photocatalyst exhibits the best hydrogen evolution rate and TC photodegradation performance, respectively. Notably, the optimum hydrogen production rate is 6 times that of pure ZIS with excellent cycling stability. The enhanced photoactivity can be explained by the hollow corncob-like morphology and the formed S-scheme heterojunction with close interface contact between ZIS and LFO, which significantly improves the spatial separation and migration efficiency of photoexcited carriers, while maintaining a high redox potential. Finally, it provides an effective support for the photocatalytic mechanism through calculation results of density functional theory. This work not only provides a novel construction strategy of photocatalysts for efficient photocatalytic hydrogen evolution and organic pollutant degradation, but also opens up a new insight for perovskite-modified S-scheme heterojunction.