Constructing Novel Ternary Heterostructure of CeP5O14/WP/WS2 to Enhance Catalytic Activity for Hydrogen Evolution in a Full pH Range

Abstract

Tungsten sulfide (WS2), as a typical 2D layered material, is a promising electrocatalyst for the hydrogen evolution reaction (HER), while its low electrical conductivity, limited number of active sites, and inadequate intrinsic activity restrict its HER performance. Herein, the reasonable construction of cerium phosphate‐modified tungsten phosphide/tungsten sulfide composite nanosheets with ternary heterostructure on carbon cloth (CeP5O14/WP/WS2/CC) as an efficient self‐supported electrode for the HER is reported. Experimental results and theoretical analysis show that the CeP5O14 can promote the formation of WP to create rich WP/WS2 heterostructures and increase the number of oxygen vacancies in CeP5O14/WP/WS2/CC. Meanwhile, the 3D monolithic construction with more open spaces endows the CeP5O14/WP/WS2/CC with good conductivity, more exposed active sites, and high mass/electron transfer efficiency. More importantly, the synergy of CeP5O14, WP, and WS2 can efficiently tune the electronic state of the WP/WS2 heterostructure, thus optimizing the hydrogen adsorption Gibbs free energy and lowering the d‐band center of the CeP5O14/WP/WS2/CC. As a result, the optimized CeP5O14/WP/WS2/CC electrode exhibits low overpotentials of 105, 154, and 119 mV at 10 mA cm−2 with small Tafel slopes of 52, 78, and 93 mV dec−1 in acidic, alkaline, and neutral electrolytes, respectively, surpassing most of the reported WS2‐based HER electrocatalysts.

Keywords

• CeP5O14/WP/WS2 heterostructures
• electrocatalysis
• hydrogen evolution reaction
• oxygen vacancies
• self-supported electrodes