One-Step Synthesis of Bi2S3/BiOX and Bi2S3/( BiO)2CO3 Heterojunction Photocatalysts by Using Aqueous Thiourea Solution as Both Solvent and Sulfur Source

Bi2S3/BiOX (X = Cl and Br; respectively denoted as BS-BC and BSBB) and Bi2S3/(BiO)(2)CO3 (denoted as BS-BOC) heterojunction photocatalysts were easily synthesized by one-step method. In the reaction system, Bi(NO3)(3).5H(2)O could be completely dissolved in aqueous thiourea solution, which homogeneously reacted with KCl, KBr and Na2CO3 to form into uniformly mixed BS-BC, BS-BB and BS-BOC composites, respectively. The Bi2S3 content in the heterojunctions could be controlled by changing the reaction temperature, reaction time, thiourea amount and molar ratio of X/Bi or CO3/Bi. The as-prepared photocatalysts exhibited enhanced photocatalytic activity for rhodamine B (RhB) degradation under visible light irradiation in contrast with the corresponding single compounds or the composites prepared via two-step route. Excellent photocatalytic performance of the heterojunctions could be attributed to the increased visible light response, effective charge transfer from the modified band position and close interfacial contact due to well-mixed heterojunction structures. Furthermore, unique flower-like hierarchical BS-BB presented the most significant increase in photodegradation efficiency for RhB and crystal violet (CV) among three composites.