Efficient photocatalytic epoxidation of styrene over a quantum-sized SnO2 on carbon nitride as a heterostructured catalyst

Styrene oxide is a pivotal organic intermediate in pharmaceuticals and fine chemicals synthesis. However, the current synthesis process relies on the use of peroxy acid or chlorohydrin, which is incompatible with establishing a more sustainable chemical industry. Here, we reported the synthesis of a quantum-sized SnO 2 on 2D graphitic carbon nitride (CN) as a heterostructured catalyst, which displays efficient photocatalytic styrene epoxidation at room temperature using O 2 as a mild oxidant, achieving styrene conversion of 98.1% and styrene oxide yield of 71.8%. Photoelectrochemical analysis demonstrates efficient electron transferring exists from CN to SnO 2 , which enhances charge carriers’ separation and transfer processes. Furthermore, we couple the photocatalytic styrene epoxidation with epoxide ring-opening amination, achieving the synthesis of value-added β-amino alcohol in a cascade reaction fashion. This work may shed light on the heterostructured catalyst design for photocatalytic selective synthesis of valuable chemicals in a sustainable manner. • 0D/2D heterojunction of SnO 2 QDs/CN composite was synthesized via impregnation and calcination methods. • SnO 2 QDs/CN shows superb photocatalytic styrene epoxidation performance. • SnO 2 QDs/CN exhibits substrate universality for cycloalkanes, norbornene and long chain alkenes. • The SnO 2 QDs play an important role in improving the separation and transfer efficiency of photocatalysts. • A two-step reaction to synthesize β-amino alcohols was designed by combining photocatalytic epoxidation of styrene with cascade epoxide ring-opening amination reaction.