Novel Bi2S3/Bi2O2CO3 heterojunction photocatalysts with enhanced visible light responsive activity and wastewater treatment

摘要

Novel Bi2S3/Bi2O2CO3 heterojunction photocatalysts were prepared by a simple chemical reaction from commercial Bi2O2CO3. The photocatalytic activities of Bi2S3/Bi2O2CO3 were evaluated by degrading Rhodamine B (RhB) under visible light and sunlight irradiation. Further investigation revealed that the content of loading bismuth sulfide (Bi2S3) had important effects on the photocatalytic activity of the Bi2S3/Bi2O2CO3 heterojunctions, and the 5 mol% Bi2S3/Bi2O2CO3 heterojunction photocatalyst exhibited the best photocatalytic activity (30 min under visible light, λ > 400 nm). The high photocatalytic activity could be attributed to its good visible light absorption, facilitated charge separation of photogenerated electron-hole pairs and efficient charge transfer path in the partly exposed core in the heterojunctions. These benefits are derived from the unique band gap structure of the Bi2S3/Bi2O2CO3 n-n-type heterojunctions and special morphology with the partly exposed core, which was confirmed by photoluminescent spectra, surface photovoltage spectra and photoelectrochemical characterizations.