Photocatalytic selective oxidation of benzene to phenol in water over layered double hydroxide: A thermodynamic and kinetic perspective

Catalytic oxidation is one of the most important methods to generate high value-added fine chemicals in industry. However, efficient controlling the selectivity of products and avoiding over-oxidation under mild conditions remain to be challenging. Herein, the selective photocatalytic oxidation of benzene to phenol was used as the model reaction, and through tailoring the band structure for an appropriate thermodynamic driving force, Zn2Ti-layered double hydroxide (Zn2Ti-LDH) photocatalyst showed one-step oxidation of benzene to phenol in water with a high phenol selectivity of 87.18%. Detailed characterization revealed that the formed oxygen vacancies onto the surface of the LDH photocatalyst enhanced the photoinduced charge-carrier separation/transformation efficiency, increased the content of superoxide radicals, thus promoted the photocatalytic oxidation reaction. This work may serve as a guide in designing efficient photocatalysts for selective catalytic oxidation.