Oxygen vacancies induced by charge compensation tailoring Ni-doped Co3O4 nanoflakes for efficient hydrogen evolution

作者：Zhong, Wenda; Yang, Chenfan; Wu, Jing; Xu, Wenli; Zhao, Rong; Xiang, Hui; Shen, Ke^*; Zhang, Qin^*; Li, Xuanke^*

来源：Chemical Engineering Journal, 2022, 436: 134813.

DOI：10.1016/j.cej.2022.134813

• Hydrogen evolution
• Oxygen vacancies
• Charge compensation
• Co3O4
• Electronic modulation

The electronic structure modulation of the catalysts shows great significance towards hydrogen evolution re-action (HER). A charge compensation was realized by doping octahedral Ni2+ ions into the Co3O4 lattice, where the oxygen vacancies generate to maintain the electric neutrality. The oxygen vacancies lead to the local lattice distortion of Co3O4 , trigger the concomitant electron redistribution, as well as optimize the d-band center of Ni-Co3O4 . Then, the accelerated charge transfer and matter conversion boost the HER kinetics of Ni-Co3O4 . As expected, the obtained Ni-Co3O4 catalyst exhibits the brilliant HER catalytic performance with a low over-potential of only 47 mV at 10 mA cm(-2), and a Tafel slope of 46 mV dec(-1). The density function theory calcu-lations verify that this charge compensation strategy could efficiently promote the water dissociation and hydrogen transformation kinetics. Our work paves an effective avenue for rationally contriving high-efficiency catalysts towards HER.

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