▎ 摘　　要

Manganese oxide nanorods were decorated on graphene oxide using a single-step reduction of manganese salt in a one-pot reflux-assisted chemical reaction. Modified Hummer's method was employed to synthesize graphene oxide, and pristine manganese oxide nanorods were produced using a similar reflux-assisted chemical method as that of the nanocomposites. The synthesis of MnO2-GO nanocomposites was validated by several characterization techniques, including XRD, RAMAN, FTIR, FESEM, TEM, BET surface analyzer and UV-Visible spectroscopy. The average crystallite sizes of samples were estimated to be less than 10 nm with pure phases of alpha-MnO2 along with a signature (001) plane of GO. The FTIR and Raman spectra, which show the peaks of Mn-O stretching vi-brations and Raman bands of both components respectively, also support the formation of MnO2 embedded on GO sheets. The MnO2 nanorods, which are 150-225 nm long and 7-15nm thick, adhered to the GO surfaces as demonstrated by FESEM are well supported by TEM analysis. The photocatalytic performances of prepared samples were also investigated by degrading organic dyes such as methylene blue (MB) and brilliant green (BG) under visible irradiation and natural sunlight. The decolouration efficiencies of MnO2-GO nanocomposites (visible -87 % MB and -94 % BG; natural sunlight -89 % MB and -95 % BG) are much higher than that of bare MnO2 nanorods (visible -44 % MB and -79 % BG; natural sunlight -47 % MB and -78 % BG). Both dyes' reaction kinetics fit the pseudo-first-order model well, and nanocomposite removal rates were substantially faster than those of bare manganese oxide nanorods. Large specific surface area (196.5 m2g- 1), high oxygen func-tionality, and efficient adsorption sites with reduced electron-hole-pair recombination rates resulted in improved absorption of light radiation and an enhancement in the ability of MnO2-GO nanocomposites to photodegrade materials. Furthermore, the nanocomposites have a high degree of recyclability, indicating the potential of nanocomposites in practical dye pollutant removal from water.