Environmentally‐Friendly Exfoliate and Active Site Self‐Assembly: Thin 2D/2D Heterostructure Amorphous Nickel–Iron Alloy on 2D Materials for Efficient Oxygen Evolution Reaction

Abstract

A class of 2D layered materials exhibits substantial potential for high‐performance electrocatalysts due to high specific surface area, tunable electronic properties, and open 2D channels for fast ion transport. However, liquid‐phase exfoliation always utilizes organic solvents that are harmful to the environment, and the active sites are limited to edge sites. Here, an environmentally friendly exfoliator in aqueous solution is presented without utilizing any toxic or hazardous substance and active site self‐assembly on the inert base of 2D materials. Benefiting from thin 2D/2D heterostructure and strong interfacial coupling, the resultant highly disordered amorphous NiFe/2D materials (Ti3C2 MXene, graphene and MoS2) thin nanosheets exhibit extraordinary electrocatalytic performance toward oxygen evolution reaction (OER) in alkaline media. DFT results further verify the experimental results. The study emphasizes a viable idea to probe efficient electrocatalysts by means of the synergistic effect of environmentally friendly exfoliator in aqueous solution and active site self‐assembly on the inert base of 2D materials which forms the unique thin 2D/2D heterostructure in‐suit. This new type of heterostructure opens up a novel avenue for the rational design of highly efficient 2D materials for electrocatalysis.

Ruthenium Nanoparticles on Cobalt‐Doped 1T′ Phase MoS2 Nanosheets for Overall Water Splitting

“…Lately, many researchers have tried to develop TMDs as stable and highly active OER catalysts for overall water splitting. [ 22–39 ] To impart such bifunctional catalytic activity, first transition metals such as Co and Ni are frequently incorporated in various approaches, including doping in the ionic form. Yet, there have been only a few studies on the bifunctional catalytic activity of the 1T (or 1T′) phase MoS 2 .…”

Strategies to improve electrocatalytic and photocatalytic performance of two-dimensional materials for hydrogen evolution reaction

“…Theoretical calculations demonstrated that the presence of NiFe increases the stability of MoS2. Specifically, by constructing the adsorption diagram, the binding energy of the Ni atom in the plane was found to be larger [201]. Yang et al [202] reported that nickel foam can not only act as a carrier, but also provide a source of Ni (Figs.…”

Recent Progress on NiFe‐Based Electrocatalysts for the Oxygen Evolution Reaction

“…For example, Gao and co‐workers fabricated highly disordered amorphous NiFe/2D‐material (Ti 3 C 2 MXene, graphene, and MoS 2 ) heteronanosheets, which exhibited an excellent electrocatalytic performance toward the OER in alkaline media. [ 180 ] The extraordinary electrocatalytic characteristics of the NiFe/MoS 2 sheet heterostructure can be attributed to the following factors: 1) a strong interfacial coupling that contributes to fast electron transfer, 2) the nanoconfinement effect that suppresses the aggregation of active‐site NiFe nanosheets and uniformly exposes the active sites, and 3) synergism between the in situ generated gas and the ultrasonic, which solves the problem of weak van der Waals interactions between the two lamellar structures and favors the assembly of thin metal/MoS 2 ‐heterostructured hybrid nanosheets. DFT calculations further confirmed the experimental results.…”