Key Laboratory of Advanced Textile Materials and Manufacturing Technology and Engineering Research Center for Eco-Dyeing & Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University , Hangzhou 310018, People's Republic of China.
College of Physics and Electronic Information, Gannan Normal University , Ganzhou, Jiangxi 341000, People's Republic of China.
ACS Appl Mater Interfaces. 2017 Sep 6;9(35):29660-29668. doi: 10.1021/acsami.7b06377. Epub 2017 Aug 22.
A facile and effective strategy for fabricating a three-dimensionally (3D) structured nanocomposite catalyst based on nonprecious metals for water splitting in alkaline electrolyzers is reported in this paper. This nanocomposite catalyst consists of the CdS quantum dots (QDs) decorated NiS nanosheet flowers deposited on the plasma-treated nickel foam (PNF). The NiO formed during the plasma treatment is shown to play an important role for pushing the hydrogen and oxygen evolution reactions (HER and OER) in alkaline media. The enhanced exposure of active sites on the nanopetalages results in superior catalytic performance for promoting HER and OER in alkaline electrolyzers. Specifically, a current density of 10 mA cm can be achieved for the HER with a 121 mV overpotential when the working electrode based on the 1 mM CdS/NiS/PNF catalyst is employed in 1 M KOH. The corresponding Tafel slope is 110 mV/decade. For the OER, the onset potential can be as low as 1.25 V vs reversible hydrogen electrode (RHE) reference electrode, which is substantially lower than the commercial IrO catalyst (∼1.47 V). This nanostructured catalyst has excellent long-term stability, and the linear scan voltammetry (LSV) curves of the HER and OER in 1 M KOH solution show negligible decay after undergoing 10 cycles of cyclic voltammogram. The nanocomposite material developed in this study is an ideal candidate as a catalyst for splitting water in alkaline media with relatively low overpotentials at reasonably high current densities (≥100 mA cm).
本文报道了一种在碱性电解槽中用于水分解的基于非贵金属的三维（3D）结构化纳米复合材料催化剂的简便有效策略。该纳米复合材料催化剂由CdS 量子点（QD）修饰的 NiS 纳米片花组成，沉积在等离子体处理的泡沫镍（PNF）上。研究表明，等离子体处理过程中形成的 NiO 对推动碱性介质中的析氢和析氧反应（HER 和 OER）起着重要作用。纳米花瓣上活性位的增强暴露导致在碱性电解质中促进 HER 和 OER 的催化性能得到提高。具体而言，当在 1 M KOH 中使用基于 1 mM CdS/NiS/PNF 催化剂的工作电极时，HER 的电流密度为 10 mA cm 时，过电位为 121 mV。相应的塔菲尔斜率为 110 mV/decade。对于 OER，起始电位可以低至 1.25 V 相对于可逆氢电极（RHE）参考电极，这明显低于商用 IrO 催化剂（约 1.47 V）。这种纳米结构的催化剂具有优异的长期稳定性，在 1 M KOH 溶液中的 HER 和 OER 的线性扫描伏安（LSV）曲线在经历 10 个循环伏安循环后几乎没有衰减。本研究开发的纳米复合材料是一种理想的催化剂，用于在相对较低的过电位和较高的电流密度（≥100 mA cm）下在碱性介质中分解水。
