Solar-Driven Selective Benzyl Alcohol Oxidation in Pickering Emulsion Stabilized by CNTs/GCN Hybrids Photocatalyst

Herein, a bi-functional composite photocatalyst was synthesized by integrating carbon nanotubes (CNTs) and graphitic carbon nitride (GCN) via a facile electrostatic self-assembly strategy. The resulting CNTs/GCN composite served dual roles as both a solid emulsifier and a photocatalyst, enabling highly efficient photocatalytic benzyl alcohol oxidation within a Pickering emulsion system. The relationship between emulsion droplet size and solid emulsifier dosage was investigated and optimized. The enhanced photocatalytic function was supported by an improved photocurrent response and reduced charge-transfer resistance, attributed to superior charge separation efficiency. Consequently, the benzyl alcohol conversion efficiency achieved in the Pickering emulsion system (58.9%) was three-fold of that observed in a traditional oil–water non-emulsion system (19.0%). Key active species were identified as photoholes, and an interfacial reaction mechanism was proposed. This work provides a new approach for extending photocatalytic applications in aqueous environments to diverse organic conversion reactions through the construction of multifunctional photocatalysts.