▎ 摘 要
A facile low temperature approach was used to synthesize gamma-MnO2 on the surface of graphene oxide (GO) through a simple wet precipitation method using MnSO4 as a precursor. X-ray diffraction analysis and Raman spectroscopy confirmed the formation of gamma-phase MnO2 in the MnO2/GO nanocomposites. Transmission electron microscopy studies showed that gamma-MnO2 exists as flower and needle structures in GO with an average size of approximately 15 nm. Inductively coupled plasma atomic emission spectroscopy studies confirmed a 62.5 wt% loading of gamma-MnO2 in the GO nanocomposites. The gamma-MnO2/GO catalyst shows good activity for the selective aerobic oxidation of benzyl alcohols to corresponding carbonyl compounds even when present in sub-stoichiometric amounts giving 91% yield over 3 h under mild reaction conditions. The catalyst showed high activity even after three cycles indicating good recyclability.