Lu Jiaxin, Hao Wenke, Wu Xiaodong, Shen Xiaodong, Cui Sheng, Shi Wenyan
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China.
Department of Electromechanical inspection, Product Quality Supervising and Inspecting Institute of Taizhou, Taizhou 225300, China.
Gels. 2023 Feb 28;9(3):190. doi: 10.3390/gels9030190.
It remains a big challenge to develop non-precious metal catalysts for oxygen evolution reaction (OER) in energy storage and conversion systems. Herein, a facile and cost-effective strategy is employed to in situ prepare the Ni/Fe oxyhydroxide anchored on nitrogen-doped carbon aerogel (NiFeO(OH)@NCA) for OER electrocatalysis. The as-prepared electrocatalyst displays a typical aerogel porous structure composed of interconnected nanoparticles with a large BET specific surface area of 231.16 m·g. In addition, the resulting NiFeO(OH)@NCA exhibits excellent OER performance with a low overpotential of 304 mV at 10 mA·cm, a small Tafel slope of 72 mV·dec, and excellent stability after 2000 CV cycles, which is superior to the commercial RuO catalyst. The much enhanced OER performance is mainly derived from the abundant active sites, the high electrical conductivity of the Ni/Fe oxyhydroxide, and the efficient electronic transfer of the NCA structure. Density functional theory (DFT) calculations reveal that the introduction of the NCA regulates the surface electronic structure of Ni/Fe oxyhydroxide and increases the binding energy of intermediates as indicated by the d-band center theory. This work provides a new method for the construction of advanced aerogel-based materials for energy conversion and storage.
在储能和转换系统中开发用于析氧反应（OER）的非贵金属催化剂仍然是一个巨大的挑战。在此，采用一种简便且经济高效的策略原位制备了锚定在氮掺杂碳气凝胶上的氢氧化镍铁（NiFeO(OH)@NCA）用于OER电催化。所制备的电催化剂呈现出典型的气凝胶多孔结构，由相互连接的纳米颗粒组成，具有231.16 m²·g的大BET比表面积。此外，所得的NiFeO(OH)@NCA表现出优异的OER性能，在10 mA·cm²时过电位低至304 mV，塔菲尔斜率小至72 mV·dec⁻¹，并且在2000次循环伏安循环后具有出色的稳定性，优于商业RuO₂催化剂。OER性能的显著提高主要源于丰富的活性位点、氢氧化镍铁的高电导率以及NCA结构的高效电子转移。密度泛函理论（DFT）计算表明，NCA的引入调节了氢氧化镍铁的表面电子结构，并根据d带中心理论增加了中间体的结合能。这项工作为构建用于能量转换和存储的先进气凝胶基材料提供了一种新方法。
