Boosting the Electrocatalysis of MXenes by Plasmon‐Induced Thermalization and Hot‐Electron Injection

The MXenes attract great interest in catalytic and energy applications but suffer from inferior redox activity. An efficient strategy is presented to boost the intrinsic electrochemical activity of MXenes for electrocatalysis in various chemical environments by utilizing their plasmonic response to electromagnetic waves. The resulting significant thermoplasmonic effect lowers the endothermic enthalpy and potential barrier to the hydrogen evolution reaction (HER) in the Vis/near‐IR region. Simultaneous hot‐electron injection in a prolonged sub‐femtosecond to picosecond timescale also remarkably facilitates interfacial charge transfer and decreases the activation energy of the reaction. Both effects boost the HER activity of various types of MXenes over fivefold with improved kinetics and Faradaic efficiency over a broad pH range. The electrocatalytic activity of MXenes can be boosted by utilizing their plasmonic response to electromagnetic waves. The resulting intense photothermal effect and hot‐electron injection reduces the endothermic enthalpy, activation energy, and interfacial charge transfer resistance of the hydrogen evolution reaction on various types of MXenes over a broad pH range.