Djurleite Copper Sulfide-Coupled Cobalt Sulfide Interface for a Stable and Efficient Electrocatalyst

Abstract

Transition metal sulfides (TMS) exhibit proliferated edge sites, facile electrode kinetics, and improved intrinsic electrical conductivity, which demand low potential requirements for total water splitting application. Here, we have propounded copper sulfide-coupled cobalt sulfide nanosheets grown on 3D nickel as an electrocatalyst for hydrogen (HER) and oxygen evolution (OER) reactions. The formation of djurleite copper sulfide with a Cu vacancy enables faster H+ ion transport and shows improved HER activity with a remarkably lower overpotential of 164 mV at 10 mA/cm2, whereas cobalt-incorporated copper sulfide undergoes cation exchange during synthesis and shows elevated OER activity with a lower overpotential of 240 mV at 10 mA/cm2 for the OER. Moreover, Cu2–x S/Co is said to have a hybrid CoS–CoS2 interface and provide Co2+ active sites on the surface and enable the fast adsorption of intermediate species (OH*, O*, and OOH*), which lowers the potential requirement. The copper vacancy and cation exchange with a hybrid CoS–CoS2 structure are helpful in supplying more surface reactive species and faster ion transport for the HER and OER, respectively. The full-cell electrolyzer requires a very low potential of 1.58 V to attain a current density of 10 mA/cm2, and it shows excellent stability for 50 h at 100 mA/cm2 as confirmed by the chronopotentiometry test.

Rational Assembly of the NiMoP/NiCoZn Heterostructure Electrocatalyst for the Hydrogen Evolution Reaction at High Current Densities

“…Recently, tremendous collaborative efforts have been undertaken to identify efficient non-noble metal-based electrocatalysts. Currently, transition-metal elements, such as molybdenum, nickel, , copper, , iron, chromium, , tungsten, , cobalt, , and manganese, and their corresponding nitrides, , phosphides, , sulfides, , carbides, oxides/hydroxides, , and borides are regarded as leading candidates for the HER owing to their subtle electron properties and satisfactory electrocatalytic activities. Although efficiencies at low current density have rapidly increased, functional electrodes for high-speed water splitting remain limited .…”

Thermal and electrical properties of nanocrystalline superionic NaxCu1.75S (x=0.1, 0.15, 0.2, 25) compounds

“…Nanocrystalline copper sulfides and selenides have a wide range of applications due to their interesting and varied physical properties: for example, solar cells [1,2], nanosized switches [3], photoluminescence sensors of barely visible impact damage [4], photoluminescence gas and humidity sensors [5], sensors of vapors of some organic compounds [6], plasmonic applications in synergistic therapies of near-infrared rays and magnetic resonance imaging [7], catalysts [8,9], materials for photothermal therapy [10] and cetera. The most attractive, in our opinion, are the thermoelectric and electrochemical applies [11,12].…”

CoO–Co Heterojunction Covered with Carbon Enables Highly Efficient Integration of Hydrogen Evolution and 5-Hydroxymethylfurfural Oxidation

“…Renewable-energy-driven electrochemical water splitting for hydrogen production is a promising avenue for synchronously weakening our dependence on conventional fossil fuels and mitigating the associated environmental issues by providing affordable clean energy [ 1 , 2 , 3 , 4 ]. For electrolytic water splitting, relative of hydrogen evolution reaction (HER), oxygen evolution reaction (OER) at the anode generally accounts for most of the energy consumption of the system, by virtue of its high-barrier thermodynamics and the sluggish reaction kinetics [ 3 , 5 , 6 , 7 , 8 , 9 ]. Moreover, the low-value product, O 2 , limits the economy considerably [ 10 , 11 , 12 ].…”