The Customization of Phosphorus Terminal for MXene Materials by Photothermal Effect Toward High‐Performance Zn‐Ion Hybrid Supercapacitors

ABSTRACT MXene materials exhibit outstanding pseudocapacitive performance, holding great potential for application in zinc‐ion hybrid supercapacitors (Zn‐HSCs). Exploring the effect of the surface terminal regulation on the performance of MXene is crucial yet challenging. In this study, the phosphorus‐terminal groups (P─C and P─O) with a P concentration of 2.71 at% are successfully tailored and interlayer spacing is enhanced during the ultraviolet light irradiation process of Ti 3 C 2 T x MXene, which is the first report of photoinduced P‐doped MXene modification. Density functional theory calculations show that P doping is more likely to be adsorbed by ─O groups than to replace Ti vacancy, and the stability of the MXene electrode can be improved by the introduction of a phosphorus terminal. The resulting P‐doped Ti 3 C 2 T x MXene shows a significant increased pseudocapacitance performance, achieving superior results compared with traditional resistance furnace heating methods. The specific capacitance achieves 500.5 F g −1 , due to the ─P functional group and Ti atom double reoxidation sites. Furthermore, a Zn‐HSC device of P‐doped Ti 3 C 2 T x exhibits a specific capacitance of 207.4 F g −1 and energy densities of 56.5 Wh kg −1 . This study also provides valuable insights and a reference for the realization of phosphorus doping in other MXene materials.