In-situ growth of hierarchically porous FeNi2S4/Ti3C2Tx nanosheets arrays on Ni-Fe foam for overall water splitting

Ti 3 C 2 T x nanosheets arrays sandwiched with FeNi 2 S 4 nanoparticles are in-situ grown on Ni-Fe foam (FeNi 2 S 4 -Ti 3 C 2 T x @NFF) via a facile one-pot hydrothermal route. The as-prepared FeNi 2 S 4 -Ti 3 C 2 T x @NFF exhibits simultaneously excellent catalytic activity towards oxygen and hydrogen evolution reactions with low overpotentials (136 and 97 mV at 10 mA cm -2 , respectively) and superior stability. Moreover, a symmetrical electrolyzer utilizing FeNi 2 S 4 -Ti 3 C 2 T x @NFF as the anode and cathode only requires 1.51 V for overall water splitting to reach 10 mA cm -2 , and can continuously operate at 20 mA cm -2 for 100 h. The outstanding catalytic performance of the catalyst can be attributed to increased active sites in the well-dispersed FeNi 2 S 4 nanoparticles, enhanced electronic conductivity due to introduction of Ti 3 C 2 T x nanosheets, strong electronic coupling between Ti 3 C 2 T x and FeNi 2 S 4 , improved mass transfer through the hierarchically porous structures and robust self-supporting configuration.