Hard-templated preparation of mesoporous cobalt phosphide as an oxygen evolution electrocatalyst

Herein, we examine the application of mesoporous cobalt phosphide (meso-CoP) prepared by a hard-templating method as a novel non-precious electrocatalyst for the oxygen evolution reaction (OER). The obtained meso-CoP exhibits a relatively low overpotential (0.30 V at 10 mA cm−2), a decent Tafel slope (81 mV dec−1), and good long-term stability, performing better than its bulk counterpart and many state-of-the-art Co-based OER electrocatalysts. The high electrocatalytic performance of the meso-CoP toward OER is attributed to two key factors: (1) a large accessible active surface which endows the meso-CoP with numerous active sites for water oxidation; (2) a well-organized mesoporous structure which expedites the electron/ion transfer and mass transport, thereby significantly enhancing the OER kinetics. This work will provide guidance for designing inexpensive high-performance electrocatalysts with exquisite mesostructures for potential applications in commercial water-splitting technology. •The hard-templated synthesis of mesoporous cobalt phosphide (meso-CoP) is presented.•High density of exposed active sites of well-developed meso-CoP architectures•The obtained meso-CoP catalyst displays a relatively low overpotential of 300 mV at 10 mA cm−2.•The as-prepared meso-CoP catalyst exhibits negligible OER activity loss up to 2000 cycles.