Controlling incorporation of TiO2 nanoparticles in the carbonization process: a new strategy to develop a nitrogen-doped carbon-based Mo2C@TiO2 electrocatalyst for electrochemical hydrogen evolution reaction

The rational design of an active and stable electrocatalyst for the hydrogen evolution reaction (HER) is demonstrated as a major challenge for the renewable energy-driven water-splitting process. Herein, a unique structure of nitrogen-doped carbon-based Mo2C@TiO2 (NC/Mo2C@TiO2) was synthesized via controlling incorporation of TiO2 nanoparticles in the carbonization process to achieve promising electrocatalytic activity towards the HER. The electronic structure of Mo2C nanodots was regulated by TiO2 and nitrogen-doped carbon, thus exposing abundant active sites for the HER. Electrochemical measurement shows that the NC/Mo2C@TiO2 electrocatalyst has a low overpotential of 167 mV at 10 mA cm−2 with a Tafel slope of 158 mV dec−1 in 1 M KOH. The electrocatalyst shows excellent stability with a slightly declined current density of 92.88% after 35 h of operation because of the involvement of TiO2. Moreover, the design concept can be extended to developing other transition metal carbide electrocatalysts.