Decatungstate synergizing with K+/cyano-functionalized carbon nitride for selective photooxidation of cyclohexane to KA oil

Merely 1.2 wt% KCCN elevates cyclohexane conversion to 64.47%, 2.5-fold that of pure QA-DT. • QA-DT performs HAT cleavage, while KCCN activate O 2 , enabling an efficient catalytic cycle. • The system achieves high ketone/alcohol selectivity (K/A ratio ∼5) and total selectivity > 95%. • The nanosheet-cluster interface boosts visible light absorption and stabilizes the catalyst. The selective oxidation of cyclohexane to KA oil holds significant importance in both fundamental research and industrial applications, with the formation of cyclohexyl hydroperoxide serving as a crucial rate-determining step. In this study, a hybrid material designated as QA-DT@KCCN was constructed through the in-situ composition of potassium/cyano-comodified carbon nitride nanosheets (KCCN) and quaternary ammonium-decatungstate (QA-DT), aiming to enhance the mass transfer efficiency of O 2 and improve the utilization efficiency of hydrogen atom transfer products. The results demonstrate that a minimal KCCN doping of 1.2 wt% significantly enhanced the photocatalytic oxidation performance. Under light irradiation in acetonitrile for 2 h, a cyclohexane conversion rate of 64.47% was achieved (compared to 25.18% with pure QA-DT), with a ketone/alcohol ratio of 5.02 and overall selectivity exceeding 95%. Radical quenching and trapping experiments confirmed that superoxide anion radicals (•O 2 - ) and holes (h + ) are the key active species in this photocatalytic system. The unique nanosheet-cluster interfacial coupling effect in the hybrid material not only facilitates directional electron transfer but also enhances visible light absorption and stabilizes the ionic structure of decatungstate. This study provides a novel strategy for designing high-efficiency decatungstate catalysts, offering valuable insights to advance the technology of selective inert hydrocarbon oxidation. Download: Download high-res image (208KB) Download: Download full-size image