Directly Electrodeposited Cobalt Sulfide Nanosheets as Advanced Catalyst for Oxygen Evolution Reaction

Abstract

CoS, a low cost and efficient electrocatalyst for oxygen evolution reaction (OER), has attract great research interest but its electrosynthesis to delicately tune the nanostructures has not been carried out. Herein, for the first time by the use of potassium thiocyanate (KSCN) as sulfur source, CoS nanosheets are time‐controlled electrosynthesized and further evolved to a 3D flower‐like nanostructure, in which KSCN plays a critical role. With a deposition time of 1200s, the catalyst shows excellent catalytic activity toward OER, achieving a small Tafel slope of 55 mV dec−1 and only requires an overpotential of 310 mV to deliver a current density of 10 mA cm−2, better than the benchmark IrO2 and other electrodeposited cobalt sulfide catalysts. The enhancement mechanism is attributed to the unique nanostructure offering a large electroactive surface while allowing reactants accessing the reaction surface and the produced oxygen bubble escaping out for a fast electrode kinetics toward OER.

Cathodic Electrodeposition of Stoichiometric Cobalt Chalcogenide Thin Films

“…Note that bulk cobalt sulfate formation can be neglected owing to the high solubility of this compound. 29 The two-step approach could be extended to another Cochalcogenide, CoSe. A linear sweep voltammogram was obtained using a Se-modified electrode in a 0.1 M Na 2 SO 4 blank electrolyte to examine whether a two-step approach could be applied to the formation of CoSe films (Fig.…”

A Review of Transition Metal Boride, Carbide, Pnictide, and Chalcogenide Water Oxidation Electrocatalysts

“…Moreover, the shorter diffusion pathways in these 2D nanostructures can accelerate the electron charge transfer, making them promising materials for energy storage and conversion technologies . Among the different types of 2D nanostructured sulfides that have been investigated for the electrocatalysis of the OER, nanosheets (refs , , , , , , , , , , , , , , , , and ), nanoplates, , nanoneedles, ,, and nanobelts are the most reported in the literature. In addition, there are also reports that directly studied the effect of 2D vs 1D nanostructured sulfides on OER performance.…”

One-step potentiostatic electrodeposition of NiS–NiS2 on sludge-based biochar and its application for a non-enzymatic glucose sensor

“…Nickel suldes were in situ electrodeposited on the surface of sludge-based biochar due to electrodeposition having signicant advantages of relatively low cost, easy operation, and well condition controlling. 21,22 Consequently, the NiS-NiS 2 /sludge-based biochar/GCE was constructed (Scheme 1). This proposed sensor was low-cost, eco-friendly, sensitive and convenient.…”