Oxygen vacancy optimization of the titanium carbide MXene surface for enhanced electrochemical nitrogen reduction

• Published in: Applied surface science 2024-08, Vol.663, p.160140, Article 160140
• Main Authors: Tao, Leiming, Guo, Zhe, Pang, Kui, Zeng, Zhanqiang, Wang, Chen, Huang, Liming, Zhu, Guanhua, Duan, Linhai, Yang, Jianjun, Li, Qiuye
• Format: Article
• Language: English
• Subjects: Density functional theory; Electrocatalysis; MXenes; N2 reduction; Oxygen vacancy
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2024.160140

[Display omitted] •This research rationally integrates defect engineering to create oxygen vacancy-rich Ti3C2-MXene (K-Ti3C2-400).•The K-Ti3C2-400 achieves NH3 yields of 32.25 ± 0.8 μg·h−1·mg−1cat. at −0.55 V and FE values of 12.85% ± 0.26% at −0.45 V (vs. RHE).•The oxygen vacancies generate on the surface of Ti3C2 significantly enhance its electron transfer ability and NRR performance.•Oxygen vacancies can prevent the HER by delaying H adsorption, thereby activating absorbed N2 and encouraging *N2H synthesis. Electrochemical N2 reduction reaction (NRR) provides a hopeful way for sustainable NH3 production. It is the key to realize efficient NRR reaction to optimize the structure and electronic configuration of catalyst materials. Increasing the number of active centers in Ti3C2Tx MXene allows for the development of effective NRR electrocatalysts. Herein, we rationally integrated defect engineering to create oxygen vacancy-rich Ti3C2-MXene (K-Ti3C2-400) as an efficient NRR catalyst with an NH3 yield of 32.25 ± 0.8 μg·h−1·mg−1cat. at − 0.55 V and a Faradaic efficiency of 12.85 % ± 0.26 % at −0.45 V versus reversible hydrogen electrode. According to the density functional theory, oxygen vacancies can prevent the hydrogen evolution reaction by delaying H adsorption, thereby activating absorbed N2 and encouraging *N2H synthesis. This research opens up new possibilities for creating MXene-based catalysts with surface reactivity and selectivity for electrochemical N2 fixation.