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 SnO₂ on 2D graphitic carbon nitride (CN) as a heterostructured catalyst, which displays efficient photocatalytic styrene epoxidation at room temperature using O₂ 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 SnO₂, 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.