Defect-engineered MoO3-x coupled with AuAg nanoalloys for efficient photoelectro-oxidation of cyclohexane to KA oil

The selective oxidation of inert C-H bonds in cycloalkanes to high-value KA oil (the mixture of cyclohexanone and cyclohexanol) is a major industrial challenge, primarily due to the inherent trade-off between conversion and selectivity. To address this, we developed a novel photoelectrocatalyst for the oxidation of cyclohexane under ambient conditions. The catalyst was constructed by first synthesizing blue, oxygen-vacancy-rich MoO 3-x nanowires via a hydrothermal method, followed by the in-situ deposition of AuAg alloy nanoparticles with tunable compositions. Comprehensive characterization confirmed the uniform distribution of the alloy nanoparticles and the formation of a Schottky heterojunction with the MoO 3-x support. This design promotes efficient separation of photogenerated charge carriers and enhances visible-light absorption through the localized surface plasmon resonance (LSPR) effect. During photoelectrocatalytic oxidation, the optimized catalyst (MoO 3-x -Au 20 Ag 20 ) exhibited exceptional performance, achieving a cyclohexane conversion of 30.24% with 93.7% selectivity to KA oil under 2.6 V applied bias and 2 h of irradiation. This represents a 1.9-fold increase in conversion compared to pristine MoO 3-x nanowires. This work provides an efficient and selective pathway for alkane oxidation and advances the strategy for designing synergistic photoelectrocatalytic systems.