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

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.