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

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 (Ti3C1.8N0.2 and Ti3C1.6N0.4) using an in situ nitrogen solid solution, followed by an etching process. The introduction of nitrogen is beneficial to the Ti3C1.6N0.4 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 Ti3C1.6N0.4 catalyst exhibits enhanced electrocatalytic properties for OER, which include a small ηonset 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.