Hierarchical Co-Mo-S nanoflowers as efficient electrocatalyst for hydrogen evolution reaction in neutral media

The development of hydrogen evolution reaction (HER) catalysts composed of inexpensive and abundant elements is an effective strategy to realize the hydrogen economy, particularly in neutral media. Herein, we report the design and synthesis of a series of hierarchical Co-Mo-S nanoarchitectures by a facile and efficient hydrothermal method in a water-ethylene glycol mixed solvent system. Such as-synthesized bimetallic sulfide samples as HER electrocatalysts exhibit good performance in phosphate buffer solution (1 M PBS), especially Co-Mo-0.4-S nanocomposite (0.4 is the molar number of Na2MoO4.2H(2)O adding in the experimental section) shows the highest activity for HER. Co-Mo-0.4-S only requires an over potential of 213 mV to reach 10 mA cm(-2) with 94 mV dec(-1) of Tafel slope, which outperforms those of Co-S (455 mV) and Mo-S (>500 mV). The excellent HER performance of Co-Mo-0.4-S electrocatalyst can be attributed to the strong electronic interactions of Co-S and Mo-S, the improvement electrical conductivity and the high specific surface. In addition, such a Co-Mo-0.4-S nanoflower may be employed as a promising non-precious electrocatalyst for HER to substitute the Pt/C material in neutral media. (C) 2020 Elsevier B.V. All rights reserved.