Polyoxometalate Compound-Derived MoP-Based Electrocatalyst with N-Doped Mesoporous Carbon as Matrix, a Cathode Material for Zn-H+ Battery.

H2 is confirmed as a perfect substitute for traditional fossil energy, which can be obtained through hydrogen evolution reaction (HER) after electrocatalytic H2O decomposition. High-performance electrocatalysts play a significant role in HER. Here, with coordination complex-modified Standberg-type polyoxometalate and peach juice as precursors, MoP-based electrocatalysts with N-doped mesoporous carbon as a matrix (MoP@NMC) were obtained. Remarkably, during synthesis, the extremely poisonous PH3 and highly explosive H2 were avoided. MoP@NMC exhibits very excellent electrocatalytic activity in acidic electrolytes. To get 10 mA·cm-2 current, MoP@NMC only requires 92 mV overpotential with Tafel slope 56 mV·dec-1. It also possesses perfect long time stability and durability in HER. More importantly, with MoP@NMC as the cathode and the Zn plate serving as the anode, a new type of battery, Zn-H+ battery, is assembled. In this Zn-H+ battery, Zn provides electrons, which pass through an external circuit and reach the cathode. Under the catalysis of MoP@NMC, the H+ ions are reduced by these electrons and form H2. The open circuit voltage of the Zn-H+ battery is 1.19 V. Its peak power density is 89.7 mW·cm-2. The energy density of this Zn-H+ battery arrives at 809 W h·kg-1 at 10 mA·cm-2. This work establishes a new piece of research field for HER.