Enhanced Electrocatalytic Hydrogen Evolution from Large-Scale,Facile-Prepared, Highly Crystalline WTe2 Nanoribbons with WeylSemimetallic Phase
Enhanced Electrocatalytic Hydrogen Evolution from Large-Scale,Facile-Prepared, Highly Crystalline WTe2 Nanoribbons with WeylSemimetallic Phase
复制标题
具有 Weyl 半金属相的大规模、易于制备、高度结晶的 WTe2 纳米带增强电催化析氢
DOI：
10.1021/acsami.7b13387
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发表时间：
2018
影响因子：
9.5
通讯作者：
Haixin Chang
中科院分区：
文献类型：
--
作者：
Jie Li;Meiling Hong;Leijie Sun;Wenfeng Zhang;Haibo Shu;Haixin Chang
二碲化钨（WTe 2）是一种重要的层状过渡金属二硫属化合物（TMD），具有多种优异的物理性能。目前制备WTe 2的方法都需要高温等苛刻的条件，或者不能大规模应用，限制了其实际应用。此外，对WTe 2的研究主要集中在其物理性质上，而对其电化学性质的研究还不多。在这里，我们开发了一个简单的和可扩展的两步法合成高品质的WTe 2纳米晶体与1 T ′ Weyl半金属相的第一次。通过这两步方法可以大规模地获得高度结晶的1 T ′-WTe 2纳米带。电化学测试结果表明，在相同的制备条件下，WTe 2纳米带的析氢反应过电位明显低于相同形貌的其他钨基硫化物和硒化物（WS 2，WSe 2）纳米带。WTe 2纳米带显示出57 mV/dec的塔菲尔斜率，这是TMD催化剂的最佳值之一，并且分别比2 H-WS 2纳米带（135 mV/dec）和2 H-WSe 2纳米带（213 mV/dec）小约2倍和4倍。1 T ′-WTe 2纳米带在10 mA/cm 2电流密度下循环5000次、20 h后仍保持稳定性。这是由于半金属1 T ′相稳定WTe 2纳米带的高导电性，其电荷转移速率比正常半导体2 H相稳定的WS 2和WSe 2纳米带高一个或两个数量级。这些结果为外尔半金属TMD的电化学应用打开了大门。
Tungsten ditellurium (WTe2) is one of most important layered transition metal dichalcogenides (TMDs) and exhibits various prominent physical properties. All the present methods for WTe2 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 WTe2 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 WTe2 nanoribbon crystals with 1T′ Weyl semimetal phase for the first time. Highly crystalline 1T′-WTe2 nanoribbons can be obtained on a large scale through this two-step method. In addition, the electrochemical tests show that WTe2 nanoribbons exhibit smaller overpotential and much better hydrogen evolution reaction catalytic performance than other tungsten-based sulfide and selenide (WS2, WSe2) nanoribbons of same morphology and under same preparation conditions. WTe2 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-WS2 nanoribbons (135 mV/dec) and 2H-WSe2.nanoribbons (213 mV/dec), respectively. 1T′-WTe2 nanoribbons also show ultrahigh stability in 5000 cycles and 20 h at 10 mA/cm2. The better performance is attributed to high conductivity of semimetallic 1T′-phase-stable WTe2 nanoribbons with one or two order higher charge-transfer rate than normally semiconducting 2H-stable WS2 and WSe2 nanoribbons. These results open the door for electrochemical applications of Weyl semimetallic TMDs.