MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China.
College of Materials Science and Engineering , Hunan University , Changsha 410082 , Hunan , People's Republic of China.
ACS Appl Mater Interfaces. 2019 Feb 6;11(5):5152-5158. doi: 10.1021/acsami.8b20717. Epub 2019 Jan 29.
Cobalt nitride electrocatalysts have been investigated and proven to show excellent oxygen evolution reaction activity owing to their excellent metallic properties, but their hydrogen evolution reaction (HER) properties are rarely reported because of their unsatisfactory molecular energy level, especially the d-orbital. Herein, taking CoN as a case study, we tune the d-orbital of metallic CoN nanowires via rapid formation of iron oxyhydroxide (FeOOH). Experimental analyses show that FeOOH@CoN/SSM exhibits excellent HER catalytic activity with considerable low onset overpotential (22 mV), small Tafel slope (34 mV dec), and excellent stability at current densities ranging from 20 to 100 mA cm. Additionally, theoretical assessments display that the hybridization of CoN with FeOOH is beneficiary for optimizing and promoting the free energy of H adsorption due to the tuning of d-orbital. An overall water-splitting device assembled based on bifunctional FeOOH@CoN/SSM delivers an onset potential of 1.48 V with excellent stability up to 4 days. This shows a new strategy for designing a high-performance water-splitting device based on cobalt-based electrocatalysts.
氮化钴电催化剂因其优异的金属性质而被证明具有优异的氧气析出反应活性，但由于其分子能级不理想，特别是 d 轨道，其析氢反应 (HER) 性能很少被报道。在此，以 CoN 为例，我们通过快速形成氧化铁 (FeOOH) 来调节金属 CoN 纳米线的 d 轨道。实验分析表明，FeOOH@CoN/SSM 表现出优异的 HER 催化活性，具有相当低的起始过电势 (22 mV)、小的塔菲尔斜率 (34 mV dec) 和在 20 至 100 mA cm 的电流密度范围内的优异稳定性。此外，理论评估显示，由于 d 轨道的调谐，CoN 与 FeOOH 的杂化有利于优化和促进 H 吸附的自由能。基于双功能 FeOOH@CoN/SSM 组装的整体水分解装置的起始电位为 1.48 V，具有长达 4 天的优异稳定性。这为设计基于钴基电催化剂的高性能水分解装置提供了一种新策略。
