School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China.
School of Chemical Engineering, Sichuan University , Chengdu, Sichuan 610065, China.
ACS Appl Mater Interfaces. 2017 Sep 13;9(36):30591-30598. doi: 10.1021/acsami.7b06613. Epub 2017 Sep 1.
Few-layered tungsten disulfide (WS) with a controlled-phase ratio (the highest trigonal-phase ratio being 67%) was exfoliated via lithium insertion. The exfoliated WS nanosheets were then anchored onto three-dimensional (3D) graphite foam (GF) to fabricate free-standing binder-free electrodes. The 3D GF can increase the interfacial contact between the WS nanosheets and the electrolyte and facilitate ion transfer. Without the nonconductive binder, an intimate contact between the WS and GF interface can be created, leading to the improvement of electrical conductivity. In comparison to the pure WS nanosheets, the overpotential for a hydrogen evolution reaction is significantly decreased from 350 mV to 190 mV at 10 mA/cm, and no deactivation occurs after 1000 cycles. The density functional theory computations reveal that the efficient catalytic activity of the trigonal-phase WS/GF electrode is attributed to the lower Gibbs free energy for H* adsorption and higher electrical conductivity.
通过锂插层剥离出具有可控相比例（最高三方相比例为 67%）的少层二硫化钨。剥离的 WS 纳米片随后锚定在三维（3D）石墨泡沫（GF）上，以制造独立的无粘结剂电极。3D GF 可以增加 WS 纳米片与电解质之间的界面接触，并促进离子转移。没有不导电的粘结剂，可以在 WS 和 GF 界面之间形成紧密接触，从而提高电导率。与纯 WS 纳米片相比，在 10 mA/cm 时析氢反应的过电位从 350 mV 显著降低到 190 mV，并且在 1000 次循环后没有失活。密度泛函理论计算表明，三方相 WS/GF 电极的高效催化活性归因于 H*吸附的较低吉布斯自由能和较高的电导率。
