Highly efficient pH-universal hydrogen evolution reaction catalyzed by rapidly reconstructed bimetallic cobalt-molybdenum alloy cuboids arrays
Daolian Liu, Zi-Hao Wang, Yan Zhang, Haiqing Zhou, Yong Zhang, Dongyang Li, Fang Yu
Abstract
Given the inherent potential of seawater, industrial wastewater, and residential water as inherent feedstocks for hydrogen production through water electrolysis, there is a critical demand for the exploration of robust and stable hydrogen-evolving catalysts that can operate effectively across a diverse range of pH conditions. However, the pursuit of hydrogen-evolving electrocatalysts that demonstrate both good stability and high efficiency over a wide pH range remains a formidable challenge. Here we report the rational design and synthesis of an outstanding nanoporous hybrid electrocatalyst consisting of intermetallic cobalt-molybdenum alloy particles anchoring on MoO2 cuboid arrays, which demands very low overpotentials of 72, 123 and 134 mV to deliver a current density of −100 mA·cm−2 for hydrogen evolution reaction under alkaline, neutral and acidic conditions, respectively. These catalytic activities are superior to most non-precious-metal-based catalysts documented in the literatures, and are even comparable to noble metal catalysts. In particular, this alloy electrocatalyst exhibits excellent stability at 50 or 300 mA·cm−2 without obvious activity degradation, which is further supported by the undetectable changes in the surface chemical valence states on the basis of in-situ X-ray photoelectron spectroscopic studies. This study provides an innovative strategy for the design and synthesis of effective non-noble intermetallic catalysts for pH-universal hydrogen evolution over a wide pH range.