Department of Chemistry and Chemical Engineering, Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, Guangzhou University , Guangzhou 510006, P. R. China.
National Engineering Center for Colloid Materials, Shandong University , Jinan 250100, P. R. China.
ACS Appl Mater Interfaces. 2017 Nov 22;9(46):40162-40170. doi: 10.1021/acsami.7b09634. Epub 2017 Nov 7.
A large surface area of catalytic sites and low electric resistance are desirable properties for electrocatalysts that lower the overpotential required for electrochemical reactions, such as the hydrogen evolution reaction (HER), in this study. In the presence of polyoxometalate (POM) and triblock copolymer pluronic (P123) as a hybrid soft template, the hydrothermal sulfurization of nickel foam leads to the formation of a hollow microsphere, assembled from the NiS motif. Sonication for preparing POM+P123 hybrids, while adjusting the POM content, is an effective strategy for synthesizing a Pt-like electrocatalyst with excellent hydrogen evolution efficiency. The reason is that both sonication and optimal POM content can simultaneously enhance the electroactive surface area and electron transfer of the NiS electrocatalyst. Adopting the optimal conditions, the three-dimensional porous network, composed of NiS hollow microspheres on the nickel foam, shows that the HER in an alkaline medium requires only 77 mV overpotential for a current density of 10 mA cm, with a robust long-term stability during a 25 h test. The performance at a large current density outperforms the current benchmark electrocatalyst (Pt) for HER.
对于降低电化学析氢反应（HER）等所需过电位的电催化剂而言，具有大的催化活性面积和低电阻是理想的特性。在多金属氧酸盐（POM）和三嵌段共聚物 Pluronic（P123）作为混合软模板存在的情况下，水热硫化镍泡沫导致 NiS 基元组成的空心微球的形成。为了制备 POM+P123 杂化物，通过超声处理并调整 POM 含量，是一种合成具有优异析氢效率的类 Pt 电催化剂的有效策略。其原因是超声处理和最佳的 POM 含量可以同时增强 NiS 电催化剂的电化学活性表面积和电子转移。采用最佳条件，镍泡沫上 NiS 空心微球组成的三维多孔网络表明，碱性介质中的 HER 仅需 77 mV 的过电位即可达到 10 mA cm 的电流密度，在 25 h 的测试中具有稳定的长期稳定性。在大电流密度下的性能优于当前 HER 的基准电催化剂（Pt）。
