Density Functional Theory Approximations and Experimental Investigations on Co_1–xMo_xTe₂ Alloy Electrocatalysts Tuning the Overall Water Splitting Reactions

Abstract

Understanding the relationship between electronic structure, surface characteristic, and reaction process of a catalyst helps to architect proficient electrodes for sustainable energy development. The highly active and stable catalysts made of earth-abundant materials provide a great endeavor toward green hydrogen production. Herein, we assembled the Co1–x Mo x Te (x = 0–1) nanoarray structures into a bifunctional electrocatalyst to achieve high-performance hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) kinetics under alkaline conditions. The designed Co0.75Mo0.25Te and Co0.50Mo0.50 electrocatalysts require minimum overpotential and Tafel slope for high-efficacy HER and OER, respectively. Furthermore, we constructed a Co0.50Mo0.50Te2∥Co0.50Mo0.50Te2 device for overall water splitting with an overpotential of 1.39 V to achieve a current density of 10 mA cm–2, which is superior to noble electrocatalyst performance, with stable reaction throughout the 50 h continuous process. Density functional theory approximations and Gibbs free energy calculations validate the enhanced water splitting reaction catalyzed by the Co0.50Mo0.50Te2 nanoarrays. The partial replacement of Co atoms with Mo atoms in the Co0.50Mo0.50Te2 structure substantially enhances the water electrolysis kinetics through the synergistic effects between the combined metal atoms and the bonded chalcogen.

Electronically modulated bimetallic telluride nanodendrites atop 2D nanosheets using a vanadium dopant enabling a bifunctional electrocatalyst for overall water splitting

“…A cutoff energy of 400 eV was set for the plane wave, while the convergence criteria for energy and force were established at 10 −2 eV Å −1 and 10 −5 eV, respectively. 27…”

“…24,25 Studies indicate that the performance of solo TMT is far from satisfactory, and can be increased by integrating different TMTs in a single platform. 26,27 TMT catalysts with multiple metals exhibit better catalytic properties than solo materials such as CoTe 2 and MoTe 2 because of the combined effects of multiple metallic active sites. Redistribution of electrons at the heterojunction influences the adsorption capacity of reactive species, enhancing catalytic performance over individual components.…”

Sonication-Induced Boladipeptide-Based Metallogel as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

“…Hydrogen, which is a sustainable and clean energy source, holds the most significant potential to replace fossil fuels. Electrochemical water splitting is viewed as a green approach for producing high-quality and affordable hydrogen energy. , This process involves two half-reactions: the cathodic hydrogen evolution reaction and the anodic oxygen evolution reaction (OER). However, the OER, which serves as a rate-determining step, has sluggish kinetics and requires a theoretical overpotential of 1.23 V. This is due to the multiple proton-coupled electron transfer process, which affects the efficiency of overall water splitting. − To overcome this problem and boost the effectiveness of water splitting, it is vital to develop materials that are highly efficient and affordable, have fast kinetics, and have long-term durability.…”