Interfacing perovskite strontium molybdate to molybdenum disulfide nanoplatelts for boosting HER from water

Due to low hydrogen adsorption free energy at the edges of 2D-MoS2 layered sheets, nanostructured MoS2 materials recently are assigned to prospective electrocatalysts for hydrogen evolution reaction (HER) from water. However, the efficiency and stability of HER onto the MoS2 designed on the conductive substrates are poor. To significantly increase the number of active sites and achieve a long-time working stability, the design of hybrid-type electrodes is crucial. Here, we report the synthesis of a new hybrid material composed of molybdenum disulfide and molybdenum oxides heterostructured with strontium molybdate. For this, a facile one-pot hydrothermal process was developed directly onto the TiO2 nanotube carpet substrate. The interfacing of strontium molybdate at the electrode substrate verified by X-ray photoelectron spectroscopy and Time of flight secondary ions mass spectrometry (ToF SIMS) techniques. Considerable higher catalytic activity at the surface of this hybrid film, with the onset potential of 190 mV vs RHE and a Tafel slope of 66 mV dec−1 attaining ~80 mA cm−2 at 0.35 V overvoltage was ascertained. Exciting HER stability in comparison with the pure synthetic MoS2 was verified by a prolonged potential cycling from 0.05 to −0.35 V versus RHE potential and 45 h continuous HER processing at a constant current density.