Visible Light‐Driven Photocatalytic Transformation of Thiols to Disulfides in Water Catalyzed by Bi₂S₃

Selective coupling of thiols to produce disulfides is one very important and classic type of coupling reactions. Herein, an environmentally friendly and practical photocatalytic system for oxidative coupling of thiols to disulfides is developed. With no sacrificial agent, no additional additive, just sole water as solvent, performed in air at room temperature, excellent conversions of thiols and excellent selectivities of disulfides are obtained using a cheap and simple semiconductor material of bismuth sulfide (Bi₂S₃) under blue LED illumination. Excellent conversions and selectivities for coupling of thiols to produce disulfides are obtained, and the system is reusable. The as‐prepared photocatalyst is adequately characterized and the mechanism of photocatalytic reaction is discussed deeply.