Self-standing Co2P2O7@N-doped carbon/carbon foams for hydrogen evolution reaction in alkaline medium

Developing an efficient non-noble metal catalyst for water splitting is very important for large-scale production of green hydrogen, but it is still a challenge due to the slow kinetics of hydrogen evolution in alkaline media. Herein, the self-standing Co2P2O7 encapsulated N doped carbon anchoring onto the skeletons of carbon foams (Co2P2O7@NC/CF) was synthesized via the phosphating and carbonization of zeolitic imidazolate framework cross-shaped nanosheets at different temperatures. Co2P2O7@NC/CF-700 showed the highest HER activity, with an overpotential of 145.7 mV and a Tafel slope of 92.6 mV dec−1 at a current density of 10 mA cm−2. Such an excellent performance is attributed to the three-dimensional interconnected, conductive carbon foams (CF) and uniformly distributed cross-shaped Co2P2O7@NC nanosheets, resulting in exposing more active sites and facilitating the mass and electron transfer.