Synthesis, Characterization and Electrocatalytic Activity for Hydrogen Evolution Reaction of Ternary Transition Metal Borides

Abstract

Recently, as the concerns on the global warming and the depletion of fossil fuels, the most immediate scientific challenge is developing clean and renewable energy. Hydrogen has focused as one of the promising alternatives to carbon-based fuels because hydrogen is eco-friendly energy. There are lots of methods to produce hydrogen. One easy and simple way to produce extremely pure hydrogen is water electrolysis, through hydrogen evolution reaction (HER). Currently, noble metals such as platinum are generally regarded as the state-of-the-art electrocatalysts for improving the kinetics and efficiency of HER. However, their prohibitive price and scarcity limit their application industrially. It is therefore highly desirable to discover highly active and stable HER electrocatalysts composed of inexpensive and earth abundant elements. In the last few years, boron based materials have been proposed as low-cost alternative electrocatalysts for HER. Recently, binary molybdenum borides (MoB, Mo 2 B, MoB 2 and Mo 2 B 4 ), iron boride (FeB 2 ) and amorphous cobalt boride (Co 2 B) were reported to have outstanding catalytic activities for the HER. In this work, we have synthesized molybdenum-tungsten diborides using solid solution synthesis. We substituted tungsten for molybdenum. The synthesized materials were characterized by X-ray power diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray analysis (EDX) and scanning electron microscope (SEM). Linear sweep voltammetry (LSV) was performed to determine the electrochemical properties by using a three electrodes system, and cyclic voltammetry (CV) was conducted to measure stability.