Zang Xiaobei, Qin Yijiang, Wang Teng, Li Fashun, Shao Qingguo, Cao Ning
School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, P. R. China.
ACS Appl Mater Interfaces. 2020 Dec 16;12(50):55884-55893. doi: 10.1021/acsami.0c16537. Epub 2020 Dec 1.
Molybdenum disulfide (MoS) has become one of the most promising non-platinum-based electrocatalysts for the hydrogen evolution reaction (HER) because of its unique layered structure. However, the catalytic performance of the thermodynamically stable MoS is hindered by its poor conductivity and scarce active sites. We developed a 3D porous N-doped graphene derivative-integrated metal-semiconductor (1T-2H) mixed phase MoS (MNG) using urea as a doping reagent. The highly exposed active sites were achieved by inducing the phase transition of MoS from 2H phase to 1T phase and the inclusion of highly N-incorporated reduced graphene oxide, both of which were simultaneously realized by optimizing the concentration of the doping reagent. Moreover, the charge/proton transfer was enhanced by the well-designed porous architecture and hydrophilic 1T-MoS. With these advantages, the optimized MNG-40 catalyst has a small overpotential of 157 mV at a cathodic current density of 10 mA cm, a relatively low Tafel slope of 45.8 mV dec, and an excellent stability. This work represents a new strategy to design higher-performance HER catalysts and provides new insights into the structural regulation of metal composite transitions.
二硫化钼（MoS）因其独特的层状结构，已成为析氢反应（HER）中最具潜力的非铂基电催化剂之一。然而，热力学稳定的MoS的催化性能受到其低导电性和稀少活性位点的阻碍。我们使用尿素作为掺杂剂，开发了一种三维多孔氮掺杂石墨烯衍生物集成的金属 - 半导体（1T - 2H）混合相MoS（MNG）。通过诱导MoS从2H相转变为1T相以及包含高度氮掺杂的还原氧化石墨烯来实现高度暴露的活性位点，这两者都是通过优化掺杂剂浓度同时实现的。此外，精心设计的多孔结构和亲水性的1T - MoS增强了电荷/质子转移。凭借这些优势，优化后的MNG - 40催化剂在阴极电流密度为10 mA cm时具有157 mV的小过电位、45.8 mV dec的相对低塔菲尔斜率以及出色的稳定性。这项工作代表了一种设计高性能HER催化剂的新策略，并为金属复合转变的结构调控提供了新的见解。
