High-active nanoplates of nitrogen-doped carbon@Mo2C as efficient catalysts in water splitting

Carbon doped metallic compounds have attracted a great deal of interest due to their new synergistic properties and enhanced catalytic performance from the doped-element induced defects. In this paper, polyaniline (PANI) is used as the carbon source to dope molybdenum carbide, which is annealed at 1000 °C to be nitrogen-doped carbon coupled with Mo2C ([email protected]2C). Through the XRD, SEM and TEM methods the prepared [email protected]2C composite is thoroughly characterized. The [email protected]2C composite illustrates two-dimensional nanoplate morphology, and shows low overpotential in hydrogen evolution reaction (HER, 0.04 V) and oxygen evolution reaction (OER, 0.13 V) in 1 M KOH solution. Tafel slopes of [email protected]2C for HER and OER are 100 mV decade−1 and 99 mV decade−1, respectively, rather lower than pure Mo2C (HER: 130 mV decade−1 and OER: 126 mV decade−1). The Raman and XPS results show that it is the structural defects of Mo2C derived from NC doping that activate the reaction. Meanwhile, the NC doping and resulted defects enhance the conductivity of Mo2C, as well as endow [email protected]2C nanoplates high electrochemical active surface area, facilitating the ion transfer, water absorption and gas desorption. The results of our work open up a new chance to design efficient non-noble metal-based catalysts for water electrolysis.