Construction of Z-scheme tungsten trioxide nanosheets-nitrogen-doped carbon dots composites for the enhanced photothermal synergistic catalytic oxidation of cyclohexane

The novel Z-scheme WO 3 nanosheets-carbon dots (CDs) composites were prepared by assembling carbon dots with different terminal groups of amine groups and carboxylic acid groups on the surface of WO 3 nanosheets. Their microtopography, structural composition, optical and electrochemical properties are further compared. The lower fluorescence intensity and interfacial resistance of WO 3 -N-doped carbon dots (NCDs) composites indicate the efficient electron transfer between the two semiconductors. The WO 3 -NCDs composites show the significantly improved photothermal catalysis activity of cyclohexane oxidation with the highest conversion of 7.88% and selectivity to KA oil of 98.9%. This performance is 1.2 times that of WO 3 -carbon dots with the carboxyl groups (CCDs) composites and 1.5 times that of pure WO 3 nanosheets. The significantly increased catalytic performance was caused by the effective Z-scheme charge transfer between NCDs and WO 3 , and the accelerated chain initiation of cyclohexane oxidation by the photothermal synergistic catalysis.