Cu/MoO2 Schottky heterojunction derived from a new designed POMOFs in-situ as high efficient electrocatalysts for hydrogen evolution reaction in universal-pH electrolytes and seawater

The design and manufacture of hydrogen evolution reaction (HER) electrocatalysts with excellent activity and stability under both acidic and alkaline conditions, even in seawater, continues to be a critical problem for clean and renewable energy systems. Herein, we have successfully fabricated the heterostructure Cu/MoO2 (NAU9500) hybrid material grown in situ derived from one of the new polyoxometallate-based metal-organic frameworks (POMOFs), that exhibited 2D layer structural CuI-POMOFs of [CuI2(Mo6O19)(bmne)2] (NAU9) containing [Mo6O19]2- clusters. When the material NAU9-500 was used as an electrocatalyst for HER, it showed excellent electrocatalytic hydrogen production performance compared with the original crystal (NAU9). NAU9-500 can drive the hydrogen evolution reaction in 0.5 M H2SO4 and 1 M KOH at a current density of 10 mA cm-2, then only needing 194 mV and 92.4 mV, respectively, which surpasses the majority of non-noble metal HER catalysts for acidic and alkaline medium. Valuably, even NAU9-500 was used in a seawater environment to exhibit excellent electrocatalytic properties and corrosion resistance. Further, the excellent HER performance in various electrolytes and seawater, the high activity and good stability for heterojunction synergistic effect processes have been meticulously researched. The hybrid material with Schottky heterojunction derived from 2D Cu-based POMOFs in situ would provide a new perspective on synthesizing low-cost and superb-performance electrocatalysts to replace noble metal catalysts.