Cu dendrites induced by the Anderson-type polyoxometalate NiMo6O24 as a promising electrocatalyst for enhanced hydrogen evolution

The design and synthesis of specific functional complex materials as desired catalysts for improved energy conversion and storage are of great importance and with grand challenges. Here, a facile synthesis strategy of Anderson POMs supported Cu dendrites toward electrochemical hydrogen evolution reaction with dramatically decreased overpotential under acidic aqueous condition is established in this work. We present the preparation of well crystallized Cu dendrites through co-electrodeposition on TiO2 array with Anderson-type POM NiMo6O24. Structural and state of valence investigation of the as-obtained electrocatalyst (NiMo6O24@Cu/TNA) evidence the specific morphology tunability and modification of Cu dendrites surfaces. During HER course, NiMo6O24 can improve the H+ transfer and further help the H atom absorption which remedies the weakness of insufficient H atom absorption ability of Cu along with its strong electron transfer lowering overpotential upon HER. Therefore, HER with NiMo6O24@Cu/TNA is considerably enhanced by decreasing related overpotential of 130 mV compared to porous Cu foam. The modification of NiMo6O24 endowed catalysts strong corrosion resistance assuring long term stability. Hence, the proposed strategy possesses improved activity and long term stability upon HER with NiMo6O24@Cu/TNA as electrocatalyst. Depending on the diversity of POMs, the current feasible and reliable heterogeneous electrocatalysts design with POMs would inspire more effective, low-cost strategies for energy conversion and open the pathway for large scale production.