Hierarchical Core-shell Heterostructures of ZnInS Nanosheets on Electrospun InO Nanofibers with Highly Enhanced Photocatalytic Activity

Well-designed heterostructure semiconductor photocatalysts can improve the activity of photocatalytic reactions. In this work, we constructed a series of hierarchical ZnInS/InO heterostructures by growing ultrathin two-dimensional ZnInS nanosheets onto one-dimensional InO electrospun nanofibers and used them as photocatalysts for the efficient photoreduction of toxic Cr(VI). This structural design increased the specific surface area, promoted the separation of photogenerated electrons and holes, and provided more active sites for the catalytic reactions. Under visible light irradiation, the optimized ZnInS/InO photocatalyst showed the highest photocatalytic performance with 100% reduction efficiency for Cr(VI) (50 mg/L) within 90 min, which is much higher than pure InO and ZnInS. Additionally, the recycling tests and X-ray diffraction (XRD) characterization indicated the stability of the ZnInS/InO photocatalyst, making it a promising candidate for environmental remediation applications. Finally, the two active species (e and ·O) participating in the photoreduction process were determined via trapping experiments and electron spin resonance (ESR) spectroscopy. Finally, a possible mechanism for the ZnInS/InO heterojunction photocatalytic system was carefully determined.