The exploration of low cost electrocatalyst with comparable catalytic activity and kinetics to the expensive noble metal catalysts for hydrogen evolution reaction (HER) is still the most urgent challenge. Herein, a facile strategy to synthesize Ti3C2Tx MXene by ultrasonication with controlled N-doping is reported. The surface modification of MXene can be achieved by the formation of Ti-N chemical bonds at an optimized ultrasonic temperature, which will further enhance the HER activity. Specifically, at the ultrasonic temperature of 35 degrees C, the N-doped MXene (N-MXene-35) exhibits the highest concentration of Ti-N bond, delivering an extraordinary HER activity with an overpotential of 162 mV (vs. the reversible hydrogen electrode, RHE) at the current density of 10 mA cm(-2) in acid media, which is 3.5 times lower than that of the pristine MXene (578 mV vs. RHE). As expected, the obtained N-MXene-35 affords the best HER electrocatalytic performance among the MXene or N-doped MXene electrode as so far reported. (C) 2020 Elsevier Inc. All rights reserved.