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Universal Descriptor for Large-Scale Screening of High-Performance MXene-Based Materials for Energy Storage and Conversion
Chemistry of Materials ( IF 7.2 ) Pub Date : 2018-03-28 00:00:00 , DOI: 10.1021/acs.chemmater.8b00156
Wei Jiang 1 , Xiaolong Zou 2 , Hongda Du 1 , Lin Gan 1 , Chengjun Xu 1 , Feiyu Kang 1 , Wenhui Duan 3 , Jia Li 1
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Density functional theory calculations are employed to systematically investigate the trend of hydrogen evolution reaction (HER) performance of oxygen-terminated MXenes. By studying 30 transition-metal carbides and 30 transition-metal nitrides, Mn+1CnO2 and Mn+1NnO2 (M = Sc, Cr, Hf, Mo, Nb, Ta, Ti, V, W, Zr; n = 1, 2, 3), the tendency of oxygen desorption after hydrogen adsorption is elucidated to play a key role in HER performance of oxygen-terminated MXenes. On the basis of these observations, we propose a suitable HER descriptor, oxygen vacancy formation energy (Ef), which scales linearly with the adsorption free energy of hydrogen, ΔGH. In addition, this new descriptor is linearly correlated with the lithium binding strength on oxygen-terminated MXenes. Therefore, Ef is a universal descriptor for identifying the trend of adsorption processes where adsorbed species donate electrons to oxygen-terminated MXenes. This work provides a general guideline for large-scale screening of promising MXene-based materials for energy storage and conversion.

中文翻译:

通用描述符,用于大规模筛选基于MXene的高性能储能和转化材料

密度泛函理论计算用于系统研究氧封端的MXenes的析氢反应(HER)性能趋势。通过研究30种过渡金属碳化物和30种过渡金属氮化物,M n +1 C n O 2和M n +1 N n O 2(M = Sc,Cr,Hf,Mo,Nb,Ta,Ti,V, W,Zr; n = 1,2,3),阐明了氢吸附后氧解吸的趋势在氧封端的MXenes的HER性能中起关键作用。基于这些观察,我们提出了一个合适的HER描述子:氧空位形成能(E f),它与氢的吸附自由能ΔG H成线性比例。另外,这个新的描述符与氧封端的MXene上的锂结合强度线性相关。因此,E f是用于确定吸附过程趋势的通用描述符,在该过程中,被吸附物质将电子提供给氧封端的MXene。这项工作为大规模筛选有前途的基于MXene的储能和转化材料提供了一般指导。
更新日期:2018-03-28
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