▎ 摘 要
It was shown that pyrolysis (900 degrees C, 3 h) of a precursor based on poly-5-aminoindole, 12-phosphomolybdic acid (PMo12), and reduced graphene oxide (rGO) leads to composite of N,P-doped rGO containing both Mo2C (predominantly) and Mo2N nanoparticles (Mo2C,Mo2N/N,P-rGO). The composition and structure of the obtained composite were studied by scanning and transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Due to the presence of various active sites in the carbonized composite (Mo2C, Mo2N, C/N-x, etc.) and their possible joint catalytic action (synergistic effect), Mo2C,Mo2N/N,P-rGO exhibits high electrocatalytic activity in the hydrogen evolution reaction (HER) in a wide pH range. The low Tafel slopes of 60 and 57 mV/dec and overpotential of 195 and 115 mV at 10 mA cm(-2) take place on Mo2C,Mo2N/N,P-rGO in 0.5 M H2SO4 and 1.0 M KOH, respectively. The electrocatalytic properties of Mo2C,Mo2N/N,P-rGO were compared with that of composites formed under the same conditions, but either using other molybdenum-containing Keggin acid-12-silicomolybdic acid, or with PMo12, but in the absence of rGO. It was found that significant differences in the chemical and phase composition of such composites, in comparison with Mo2C,Mo2N/N,P-rGO, determine their lower activity in HER in both acidic and alkaline electrolytes.