Enhanced Electrocatalytic Hydrogen Evolution from Large-Scale, Facile-Prepared, Highly Crystalline WTe₂ Nanoribbons with Weyl Semimetallic Phase

Abstract

Tungsten ditellurium (WTe) is one of most important layered transition metal dichalcogenides (TMDs) and exhibits various prominent physical properties. All the present methods for WTe preparation need strict conditions such as high temperature or cannot be applied in large scale, which limits its practical applications. In addition, most studies on WTe focus on its physical properties, whereas its electrochemical properties are still illusive with little investigation. Here, we develop a facile and scalable two-step method to synthesize high-quality WTe nanoribbon crystals with 1T' Weyl semimetal phase for the first time. Highly crystalline 1T'-WTe nanoribbons can be obtained on a large scale through this two-step method. In addition, the electrochemical tests show that WTe nanoribbons exhibit smaller overpotential and much better hydrogen evolution reaction catalytic performance than other tungsten-based sulfide and selenide (WS, WSe) nanoribbons of same morphology and under same preparation conditions. WTe nanoribbons show a Tafel slope of 57 mV/dec, which is one of best values for TMD catalysts and about 2 and 4 times smaller than that for 2H-WS nanoribbons (135 mV/dec) and 2H-WSe nanoribbons (213 mV/dec), respectively. 1T'-WTe nanoribbons also show ultrahigh stability in 5000 cycles and 20 h at 10 mA/cm. The better performance is attributed to high conductivity of semimetallic 1T'-phase-stable WTe nanoribbons with one or two order higher charge-transfer rate than normally semiconducting 2H-stable WS and WSe nanoribbons. These results open the door for electrochemical applications of Weyl semimetallic TMDs.

Synthesis of tungsten ditelluride thin films and highly crystalline nanobelts from pre-deposited reactants

“…Other works have examined WTe 2 for use in applications such as nanoscale electrical interconnects [23], electrocatalysis [24,25] and as an anode material for Na-ion batteries [26]. Additionally, WTe 2 has been touted as a promising candidate for large-gap quantum spin Hall insulators [5,21,22].…”

“…Additionally, WTe 2 has been touted as a promising candidate for large-gap quantum spin Hall insulators [5,21,22]. Lastly, through electrochemical investigations, the possibility of using WTe 2 as a catalyst for the hydrogen evolution reaction (HER) has been examined [24,[27][28][29][30].…”

Macrocycles containing 1,1′-ferrocenyldiselenolato ligands on group 4 metallocenes

“…All five complexes 1-5 form similar macrocyclic tetranuclear complexes in which the alternating Fe(C 5 H 4 Se) 2 and Scheme 1 General synthesis of 1-5. Table S1.…”

“…Compounds 4 and 5 were purified by column chromatography performed under air-excluded conditions using a stationary phase of aluminum oxide and a mixture of n-hexane : dichloromethane (1 : 2) as the eluent, with a very significant decrease in yield. Only small amounts of complexes 4 and 5 were used to record their 77 (2). A bright red polycrystal-…”

“…Transition metal dichalcogenides (TMDs) have been widely studied over the years due to their ability to intercalate species with apparent implications in catalytic and biological processes [1][2][3] and biosensors. 4 Due to their ability to intercalate species with substantial alteration of their electronic structure but minimum changes in their crystal structure, they became widely used as a new generation of semiconductors [5][6][7] and battery systems.…”