The effect of in situ nitrogen doping on the oxygen evolution reaction of MXenes

Abstract

The development of non-noble metal electrocatalysts with high performance for the oxygen evolution reaction (OER) is highly desirable but still faces many challenges. Herein, we report a facile and controllable strategy to fabricate N-doped titanium carbide flakes (Ti₃C_1.8N_0.2 and Ti₃C_1.6N_0.4) using an in situ nitrogen solid solution, followed by an etching process. The introduction of nitrogen is beneficial to the Ti₃C_1.6N_0.4 flakes for more exposed active sites, accelerated charge transfer upon an electrochemical reaction, and improved wettability for more accessible sites. As a result, the as-obtained Ti₃C_1.6N_0.4 catalyst exhibits enhanced electrocatalytic properties for OER, which include a small η_onset of 245.8 mV, low Tafel slope of 216.4 mV dec⁻¹, and relatively good catalytic stability. The present work not only deepens the understanding of in situ N-doped MXene electrocatalysts, but also provides a guideline for the preparation of other N-doped MXene-based hybrid materials for other renewable energy applications.