In-Situ and controllable construction of Mo2N embedded Mo2C nanobelts as robust electrocatalyst for superior pH-universal hydrogen evolution reaction

Abstract

The development of high active and cost-effective transition metal based catalysts as alternatives to Pt-based electrocatalysts for pH-universal hydrogen evolution reaction (HER) is highly desirable. Herein, we proposed a novel strategy to construct Mo2N uniformly embedded Mo2C nanobelt arrays electrocatalyst on N doped carbon framework (Mo2N-Mo2C/NC NBAs) by nitridation of MoOx/C hybrid precursors and subsequent annealing. The effect of N content towards the composition ratio of Mo2N to Mo2C and the structural evolution were studied. The in-situ formed Mo2N reduces the sintering of Mo2C phase and creates amounts of compact Mo2N-Mo2C interfaces and mesopores. Because of these high active interfaces, mesopores structure and self-supported architecture, the resultant Mo2N-Mo2C/NC catalyst exhibits remarkable HER performance and durability over a wide pH range, as exemplified by a small overpotentials of 75, 93, and 114 mV at 10 mA cm−2, and Tafel slopes of 43, 58, and 62 mV dec−1 in the alkaline, neutral and acidic media. The results reveal a new avenue to design highly efficient electrocatalysts with tailored hetero/microstructures, which could be extended to fabricate other high-performance electrocatalyst and electrode materials for electrochemical energy conversion.