Hierarchical Ni Modified PW12 Clusters In Situ Integrated on Ni Foam for Efficient Alkaline Hydrogen Evolution.

Polyoxometalates (POMs) with small-sized, high specific surface area, high negative charges, tunable chemical composition and unique geometrical structure, as well as self-assembly behavior have been widely employed as the transferable building block to construct target catalyst. However, there is lack of effective strategy to display their intrinsic activity for electrochemical hydrogen evolution reaction in alkaline condition. Herein, presented is Ni modified PW12 clusters in situ integrated on Ni foam with unique hierarchical structure (Ni-WO/NF), prepared from the Ni modified Keggin-type phosphotungstic acid (H3PW12O40) through the facile hydrothermal method by optimizing the volume ratio of ethanol and deionized water. The as-synthesized Ni-WO/NF possessed abundant active sites, unique micro-nanostructure, and fast charge-transfer ability at interface. Benefiting from these advantages, the optimized Ni-WO/NF exhibited superior hydrogen evolution reaction. (HER) performance with lower overpotential of 75 mV at 10 cm−2 in 1 M KOH, accompanying with a Tafel slope of 86 mV dec−1. Our discovery offers an approach to prepare heteroatom modified materials with hierarchical structure at the cost-effective HER catalysts. [ABSTRACT FROM AUTHOR]