当前位置: X-MOL 学术Small Methods › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
In Situ Construction of Flexible V?Ni Redox Centers over Ni-Based MOF Nanosheet Arrays for Electrochemical Water Oxidation
Small Methods ( IF 10.7 ) Pub Date : 2021-09-05 , DOI: 10.1002/smtd.202100573
Xuan Sun 1 , Xiuxiu Zhang 1 , Yuanli Li 1, 2 , Yanzhi Xu 1 , Hui Su 1 , Wei Che 1 , Jingfu He 3 , Hui Zhang 1 , Meihuan Liu 1 , Wanlin Zhou 1 , Weiren Cheng 1 , Qinghua Liu 1
Affiliation  

Atomic-level design and construction of synergistic active centers are central to develop advanced oxygen electrocatalysts toward efficient energy conversion. Herein, an in situ construction strategy to introduce flexible redox sites of VNi centers onto Ni-based metal–organic framework (MOF) nanosheet arrays (NiV-MOF NAs) as a promising oxygen electrocatalyst is developed. The abundant redox VNi centers with flexible metal valence states of V+3/+4/+5 and Ni+3/+2 enable NiV-MOF NAs excellent oxygen evolution reaction (OER) activity and a long-term stability under high current densities, achieving current densities of 10 and 100 mA cm−2 at recorded overpotentials of 189 and 290 mV, respectively, and showing ignorable decay of initial activity at 100 mA cm−2 after 100 h OER operation. Operando synchrotron radiation Fourier transform infrared combined with quasi in situ X-ray absorption fine structure spectroscopies reveal at atomic level that the flexible V sites can continuously accept electrons from adjacent active Ni sites to accelerate OER kinetics for NiV-MOF NAs during the reaction process, accompanied by a self-optimized structural distortion of VO6 octahedron for promoting the electrochemical stability.

中文翻译:

用于电化学水氧化的镍基 MOF 纳米片阵列上柔性 V?Ni 氧化还原中心的原位构建

协同活性中心的原子级设计和构建是开发先进氧电催化剂以实现高效能量转换的核心。在此,开发了一种原位构建策略,将 V Ni 中心的灵活氧化还原位点引入Ni基金属-有机骨架(MOF)纳米片阵列(NiV-MOF NAs)作为一种有前景的氧电催化剂。丰富的氧化还原 V Ni 中心具有灵活的金属价态 V +3/+4/+5和 Ni +3/+2使 NiV-MOF NAs 具有优异的析氧反应 (OER) 活性和高压下的长期稳定性。电流密度,实现 10 和 100 mA cm -2 的电流密度在记录的过电位分别为 189 和 290 mV,并且在 100 小时 OER 操作后在 100 mA cm -2处显示出可忽略的初始活性衰减。原位同步辐射傅里叶变换红外结合准原位X射线吸收精细结构光谱在原子水平上揭示,柔性V位点可以连续接受来自相邻活性Ni位点的电子,以加速NiV-MOF NA在反应过程中的OER动力学,伴随着VO 6八面体的自我优化结构畸变,以提高电化学稳定性。
更新日期:2021-10-28
down
wechat
bug