Electrochemical impedance spectroscopy (EIS) studies were conducted to provide insights into the charge transfer kinetics during HER. The Nyquist plots depicted in Figure show that the charge transfer resistance (R ct ) of MoS 2 @NiFeCo-Mo(doped)-LDH (22 Ω cm -2 ) is smaller than that of the other considered catalysts. Under light illumination, the charge transfer resistance decreases to less than 4 Ω cm -2 . These observations imply fast charge transfer kinetics towards HER under both dark and light conditions, and clearly illustrate the pivotal role of MoS 2 QDs in expediting charge transfer under light illumination