CoP porous hexagonal nanoplates in situ grown on RGO as active and durable electrocatalyst for hydrogen evolution

The development of efficient and low-cost hydrogen evolution reaction (HER) catalysts is critical for energy storage and conversion devices. Herein, we develop a facile method to fabricate a novel hybrid by in situ growing CoP porous nanoplates on reduced graphene oxide (RGO). The hybrid shows excellent HER performance in acid media with a low Tafel slope of 57 mV dec−1, small onset overpotential of 76 mV and long-term durability with 86.3% current density retention after 10 h electrocatalysis. The superb HER activity can be ascribed to the unique structure of porous hexagonal nanoplates. On the one hand, the porous structure provides abundant active sites for HER. On the other hand, hexagonal nanoplates provide large contact with RGO, enhancing the charge transfer ability. In addition, the hybrid with such structure shows good stability under ambient atmosphere and can maintain the initial HER activity even after six months of storage. This work demonstrates that large contact between active component and conductive support is not only beneficial to the HER activity and durability, but also beneficial to the stability of material itself.