Facile fabrication of 2D/2D step-scheme In2S3/Bi2O2CO3 heterojunction towards enhanced photocatalytic activity

To fabricate step scheme (S-scheme) heterojunction is one of the newly effective approaches to promote the photocatalytic performance of coupled semiconductors. Herein, a two-dimension (2D)/2D In2S3/Bi2O2CO3 S-scheme heterojunction photocatalyst was designed and fabricated through a facile two-step precipitation method. The as-synthetized composite presented in face-to-face hierarchical structure with enhanced photocatalytic performance towards the degradation of Rhodamine B (RhB) and tetracycline (TC) under light irradiation. The 2D/2D In2S3/Bi2O2CO3 heterojunction not only enlarges the light utilization region but also effectively restrains the recombination of useful photogenerated electron-hole pairs, which was demonstrated by diffuse reflection spectra (DRS), photoluminescence spectra (PLS) and active species trapping experiments. Particularly, the optimal performance was achieved using 10% In2S3/Bi2O2CO3 heterojunction with 91% degradation capacity towards RhB in 60 min, which was about 5 and 3 times higher than that of pure Bi2O2CO3 and In2S3, respectively. Moreover, the cycling performance of the photocatalysts further confirmed the excellent stability of the heterojunction. Based upon the characterization and experimental results, the mechanism of S-scheme heterojunction was employed to illustrate the effectively enhanced photocatalytic performance of the 2D/2D In2S3/Bi2O2CO3 heterojunction.