Heterointerface engineering of hierarchically assembling polyoxometalate on zinc/iron layered double hydroxide nanosheet as a remarkable bifunctional electrocatalyst for overall water splitting.

The design of a low-cost, highly efficient and durable electrocatalyst is very important to accelerate the energy conversion efficiency of the electrochemical process. Herein, a simple hydrothermal synthesis of the heterostructure of Wells-Dawson polyoxometalate and zinc iron layered double hydroxide nanosheet is presented for the first time on Ni-foam (ZnFe LDH-P 2 Mo 18 /NF). The electrocatalytic activity of ZnFe LDH-P 2 Mo 18 /NF shows significantly low overpotentials of 275, 330 mV and 273, 367 mV for OER and HER to acquire a current density of 20, 50 mA cm−2 respectively. Additionally, the electrolyzer composed of ZnFe LDH-P 2 Mo 18 /NF cathode and anode shows an attractive voltage of 1.54 V to carry 10 mA cm−2. The better electrochemical performance of the ZnFe LDH-P 2 Mo 18 /NF is ascribed to the variation of electronic and chemical features, growth of electrochemically active surface area/sites because of the construction of heterointerface of Wells-Dawson polyoxometalate and zinc iron LDH. These results further demonstrate the benefits of heterointerface engineering for efficient electrolysis. This study presents a novel hybrid of zinc-iron layered double hydroxide and Dawson polyoxometallate (ZnFe LDH-P 2 Mo 18 /NF) for electrocatalytic water splitting. Notably, ZnFe LDH-P 2 Mo 18 /NF reveals excellent electrocatalytic performance with a large number of electroactive sites, extremely low overpotential, and high durability throughout the water splitting process. [Display omitted] • ZnFe LDH-P 2 Mo 18 hybrid is reported first time for overall water splitting. • ZnFe LDH-P 2 Mo 18 hybrid delivers extraordinary performance for OER and HER. • The high structural integrity and ultralong durability is maintained by the hybrid. [ABSTRACT FROM AUTHOR]