Nano-control synthesis the porous network of NiCoP and F doped NiCo2Al-LDHs@ZnFeAl-LDHs nanosheets as superior catalyst for efficient overall water splitting

Abstract

Design and development superior electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to future construct a efficient overall water electrolyzer is imperative to relieve energy crisis. Herein, three-dimensional porous network of NiCoP nanosheets being covered by bimetallic phosphides nanoparticles with a ultra-small size of ∼ 7 nm anchored on nickel foam (NF) is synthesized via employing a low-cost hydrothermal and phosphorization reaction, which provides the numerous electrcatalytic active area and reactive sites, benefiting for HER behaviors. Additionally, a top-down structure of F-doped NiCo2Al-LDHs@ZnFeAl-LDHs (F-NC2AL@ZFAL) catalysts supported on NF is also fabricated by a two-step hydrothermal reaction, which could also provide promising OER performances. As expected, the as-prepared HER and OER catalysts manifest the lower overpotential of 58 and 177 mV at 10 mA cm−2 in 1 M KOH solution. Significantly, a overall water electrolyzer assembled by employing the as-prepared HER and OER catalysts displays the various cell voltages of 1.36, 1.55, 1.66, and 1.75 V at the corresponding current densities of 10, 20, 50, and 100 mA cm−2, with the excellent durability for 22 h at 100 mA cm−2. The favorable electrocatalytic behaviors imply the great potential of as-prepared electrocatalysts for overall water splitting.