One-step synthesis of BiOCO/BiS S-scheme heterostructure with enhanced photoactivity towards dibutyl phthalate degradation under visible light.

BiOCO/BiS heterojunction was prepared by one-step hydrothermal method, where Bi(NO) was employed as Bi source, NaS was used as a sulfur source, and CO(NH) was adopted as C source. The load of BiS was adjusted by changing the content of NaS. The prepared BiOCO/BiS illustrated strong photocatalytic activity towards dibutyl phthalate (DBP) degradation. The degradation rate was 73.6% under the irradiation of visible light for 3 h, which were 3.5 and 1.87 times for BiOCO and BiS, respectively. In addition, the mechanism for the enhanced photoactivity was investigated. After combined with BiS, the formed heterojunction structure inhibited the recombination of photogenerated electron-hole pair, improved the visible light adsorption, and accelerated the migration rate of the photogenerated electron. As a result, analysis of the radical formation and the energy band structure revealed that BiOCO/BiS was consistent with the S-scheme heterojunction model. The S-scheme heterojunction allowed the BiOCO/BiS to possess high photocatalytic activity. The prepared photocatalyst presented acceptable cycle application stability. This work not only develops a facile one-step synthesis technique for BiOCO/BiS, and also provides a good platform for the degradation of DBP.