Fine-tune d-band center of cobalt vanadium oxide nanosheets by N-doping as a robust overall water splitting electrocatalyst

Zuyang Luo; Qimin Peng; Zhiyang Huang; Lixia Wang; Yuting Yang; Jiaxin Dong; Tayirjan Taylor Isimjan; Xiulin Yang

doi:10.1016/j.jcis.2022.09.069

Fine-tune d-band center of cobalt vanadium oxide nanosheets by N-doping as a robust overall water splitting electrocatalyst

J Colloid Interface Sci. 2023 Jan;629(Pt B):111-120. doi: 10.1016/j.jcis.2022.09.069. Epub 2022 Sep 16.

Authors

Zuyang Luo¹, Qimin Peng¹, Zhiyang Huang¹, Lixia Wang¹, Yuting Yang¹, Jiaxin Dong², Tayirjan Taylor Isimjan³, Xiulin Yang⁴

Affiliations

¹ Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, Guangxi, China.
² Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, Guangxi, China. Electronic address: chemdjx@gxnu.edu.cn.
³ Saudi Arabia Basic Industries Corporation (SABIC) at King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia. Electronic address: isimjant@sabic.com.
⁴ Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, Guangxi, China. Electronic address: xlyang@gxnu.edu.cn.

PMID: 36152569
DOI: 10.1016/j.jcis.2022.09.069

Abstract

Developing high-activity, long-durability, and noble metal-free oxygen evolution (OER) and hydrogen evolution (HER) cocatalysts are the bottlenecks for efficient overall water splitting (OWS). Here, novel cobalt vanadium oxides doped by nitrogen were synthesized by nitriding Co₂V₂O₇@NF precursor at 300-450 °C for OER and HER reactions. N-Co₂V₂O₇@NF (350 °C) and N-Co₂VO₄/VO₂@NF (400 °C) show remarkable OER and HER performance with overpotentials of 310 mV and 224 mV at high current density (100 mA cm^-2). Besides, they also revealed long-term solid stability even after 170 h and 700 h of continuous performance. Furthermore, the N-Co₂V₂O₇@NF⁽⁺⁾||N-Co₂VO₄/VO₂@NF^(-) OWS device possesses a cell voltage of 1.93 V at 500 mA cm^-2 better than RuO₂@NF⁽⁺⁾||Pt/C@NF^(-) (2.02 V) and can operate for 60 h with almost no degradation. This extraordinary performance can be attributed to the nanosheet structure, which can maximize the exposure of active sites and accelerate the mass transfer. Moreover, density functional theory (DFT) calculations suggest that N-doping can fine-tune the d-band center and band gap to facilitate intermediate adsorption and electron motion. The method presented here can be applied in other novel N-doped electrocatalysts for the energy field.

Keywords: Cobalt vanadium oxides; Conductivity; N-doping nanosheet; Overall water splitting; Theoretical calculation.