Engineering Selenium Vacancies on CoSe₂ Nanoarrays for Alkaline Hydrogen Evolution

Abstract

The development of highly efficient nonnoble metals toward hydrogen evolution reaction (HER) electrocatalysts is significant for producing hydrogen via water electrolysis. Selenides are becoming increasingly attractive owing to their excellent HER activity. Herein, CoSe2 nanorods were successfully manufactured on a carbon cloth (CC) and selenium vacancies were obtained using a plasma cleaner (CoSe2-VSe/CC) to enhance their intrinsic catalytic activity. The synthetic catalyst exhibited a lower overpotential of 88 mV at 10 mA cm–2 in 1 M KOH and high durability over 100 h at 100 mA cm–2, which can be ascribed to the increased electrochemical surface area and rapid electron transfer. In addition, density functional theory (DFT) calculations showed that introducing Se vacancies optimized the hydrogen adsorption energy on the Se site and reduced the transition-state energy barrier of water dissociation. This study laid a firm foundation for preparing high-performance and stable electrocatalysts via anion defect engineering.

Tailored Two‐Dimensional Transition Metal Dichalcogenides for Water Electrolysis: Doping, Defect, Phase, and Heterostructure

“…Pan et al demonstrated that the HER of CoSe 2 nanorods could be promoted by the introduction of Se-vacancy. [68] The CoSe 2 nanorods with an abundance of vacancies were synthesized through subjecting CoSe 2 supported on carbon cloth (CC) to plasma treatment for varying treatment time (CoSe 2 -V se /CC-x, x: plasma treatment time). Figure 9a displays SEM images of CoSe 2 nanorods covering the surface of CC.…”

Electron transfer at the heterojunction interface of CoP/MoS2 for efficient electrocatalytic hydrogen evolution reaction

“…Transition metal sulfides, 18–21 selenides, 22–24 phosphates, 25–27 carbides 28–30 and other compounds with high activity and conductivity have drawn a lot of attention in the field of hydrogen evolution catalysts. CoP is a promising catalyst for hydrogen evolution among transition metal compounds due to its high HER activity, excellent stability and excellent conductivity.…”

Electrolyte modification method induced atomic arrangement in FeOx/NF nanosheets for efficient overall water splitting

“…Nevertheless, the high price and scarcity of these noble metals seriously impede their application. 6 Thus, it is crucial to exploit alternative, inexpensive, and highly active noble-metal-free electrocatalysts, such as transition metal (TM)-based materials. However, the performance of the TM-based electrocatalysts usually suffers from their sluggish kinetics with larger overpotential.…”