Highly Active Tungsten Oxide Nanoplate Electrocatalysts for the Hydrogen Evolution Reaction in Acidic and Near Neutral Electrolytes

Abstract

An efficient, cost-effective, and earth-abundant catalyst that could drive the production of hydrogen from water without or with little external energy is the ultimate goal toward hydrogen economy. Herein, nanoplates of tungsten oxide and its hydrates (WO 3 ·H 2 O) as promising electrocatalysts for the hydrogen evolution reaction (HER) are reported. The square-shaped and stacked WO 3 ·H 2 O nanoplates are synthesized at room temperature under air in ethanol only, making it as a promising green synthesis strategy. The repeated electrochemical cyclic voltammetry cycles modified the surface of WO 3 ·H 2 O nanoplates to WO 3 as confirmed by X-ray photoelectron and Auger spectroscopy, which leads to an improved HER activity. Hydrogen evolution is further achieved from distilled water (pH 5.67) producing 1 mA cm –2 at an overpotential of 15 mV versus the reversible hydrogen electrode. Moreover, WO 3 ·H 2 O and WO 3 nanoplates demonstrate excellent durability in acidic and neutral media, which is highly desirable for practical application. Improved hydrogen evolution by WO 3 (200) when compared to that by Pt(111) is further substantiated by the density functional theory calculations.

Highly Porous MIL-100(Fe) for the Hydrogen Evolution Reaction (HER) in Acidic and Basic Media

“… 6 , 7 Therefore, it is of utmost importance to construct a low-cost electrode with high electrocatalytic activity for the HER. 9 Metal–organic frameworks, abbreviated as MOFs, are an important family of porous crystalline solids and have received significant interest in recent years in academia and industry. These materials are constructed by metal ions, and polyfunctional organic ligands possess excellent properties with high surface area, uniform tunable porosity, physicochemical properties, and attractive optical and electrical properties that have made them useful for several potential applications, viz., gas separation, organic molecule adsorption, gas storage, catalysis, biomimetic applications, drug delivery, magnetism, and optical devices.…”

Nanostructured Molybdenum Oxides from Aluminium-Based Intermetallic Compound: Synthesis and Application in Hydrogen Evolution Reaction

“…Active sites for molybdenum oxides are reported in literature to be related to variations in the oxidation states of the material. The possible anion vacancies, which are viewed as the electrochemical active sites, stimulate the HER [ 70 , 71 ], favour the electrochemical kinetics and can also significantly increase the electrical conductivity of the electrode [ 72 ]. A similar behaviour can be inferred for SS_HF and DS_1h samples.…”

Design Principles for Tungsten Oxide Electrocatalysts for Water Splitting

“…Besides, WO 3 nanoflakes with sub‐10 nm thickness are discovered to possess exceptional thickness‐dependent HER performance [59] . The square‐shaped stacked WO 3 nanoplates exhibit an improved HER activity in both acidic and neutral electrolytes [60] . In this regard, WO 3‐x nanosheets keep a stable catalytic activity for 16 h and an overpotential of 294 mV at the current density of 10 mA cm −2 [61]…”

“…[59] The square-shaped stacked WO 3 nanoplates exhibit an improved HER activity in both acidic and neutral electrolytes. [60] In this regard, WO 3-x nanosheets keep a stable catalytic activity for 16 h and an overpotential of 294 mV at the current density of 10 mA cm À 2 . [61] Anisotropic electron transfer with high efficiency generally occurs on the surface of three dimensional (3D) structure (Figure 3i).…”