Mesoporous In2O3 nanorods/In2S3 nanosheets hierarchical heterojunctions toward highly efficient visible light photocatalysis

Construction heterostructured photocatalysis has been received as a promising approach to address the photocatalytic efficiency issues. Herein, mesoporous In2O3 nanorods/In2S3 nanosheets (In2O3/In2S3) hierarchical heterojunctions have been constructed where In2S3 nanosheets are generated on surfaces of mesoporous In2O3 nanorods through in situ anion exchange. The content of produced In2S3 nanosheets can be regulated by changing the amount of thioacetamide, with the highest specific surface area for In2O3/In2S3 can be up to 129 m2 g−1, compared to that of In2O3 nanorods (90.1 m2 g−1). The well-defined highly-inseparable heterojunctions and light absorption have been verified by the XPS and UV–vis absorption spectra analysis. The photocatalytic activity of In2O3/In2S3 heterojunctions have been firstly investigated by the model reaction (degradation of organic species), where the degradation kinetic constants for RhB and phenol are 0.0468 and 0.0312 min−1, which are approximately 5 and 3 times higher than individual In2O3 nanorods. Further investigation of the photocatalytic performances reveals that the highest H2 evolution rate of the In2O3/In2S3 heterojunctions is 800.4 μmol g−1 h−1, about 4 times higher than that of In2O3 nanorods. The enhanced photocatalytic performance for In2O3/In2S3 photocatalysis are mainly ascribed to the synergistic effect of hierarchically porous nanostructures, improved visible light absorption, enhanced specific surface area and promoted interfacial charge transfer efficiency. This work may provide a promising idea to develop advanced heterojunctions toward photocatalysis for broader applications.