One-step synthesis of Bi2O2CO3/Bi2S3 S-scheme heterostructure with enhanced photoactivity towards dibutyl phthalate degradation under visible light

Bi2O2CO3/Bi2S3 heterojunction was prepared by one-step hydrothermal method, where Bi(NO3)3 was employed as Bi source, Na2S was used as a sulfur source, and CO(NH2)2 was adopted as C source. The load of Bi2S3 was adjusted by changing the content of Na2S. The prepared Bi2O2CO3/Bi2S3 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 Bi2O2CO3 and Bi2S3, respectively. In addition, the mechanism for the enhanced photoactivity was investigated. After combined with Bi2S3, 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 Bi2O2CO3/Bi2S3 was consistent with the S-scheme heterojunction model. The S-scheme heterojunction allowed the Bi2O2CO3/Bi2S3 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 Bi2O2CO3/Bi2S3, and also provides a good platform for the degradation of DBP.