Recent progress in strategies to enhance the photocatalytic oxidation performance of cyclohexane

The photo-oxidation of cyclohexane to produce cyclohexanol and cyclohexanone (a mixture known as KA oil) is one of the important reactions in C-H activation. Cyclohexanol and cyclohexanone are important upstream products of Nylon-6 and Nylon-66 polymers. In this paper, we reviewed the related studies on the preparation of KA oil by cyclohexane photo-oxidation in recent years, and summarized the reaction mechanism of cyclohexane photo-oxidation for the preparation of KA oil. The effects of external conditions such as additives, solvents, reaction atmosphere, irradiation conditions and reaction temperature on the photocatalytic performance of cyclohexane were investigated. Based on the reaction mechanism, the effects of catalyst modification strategies (morphological optimization strategy, support strategy, surface plasmon resonance effect strategy, ion doping strategy and heterojunction engineering strategy) on the conversion of cyclohexane and the selectivity of KA oil were investigated. Finally, some challenges and opportunities for the photo-oxidation of cyclohexane for the preparation of KA oil are summarized.