FexMo1-xS2/CNT@CC nanosheets as an efficient bifunctional electrocatalyst for overall water splitting

Abstract

The FexMo1-xS2 nanosheets with different Fe doping content x were grown on carbon nanotubes @ carbon cloth (CNT@CC) substrate using a hydrothermal method by varying the molar ratio of FeSO4·7H2O to Na2MoO4·2H2O in the precursor solution. The effect on HER, OER and overall water splitting (OWS) performance of Fe doping content x were studied. The FexMo1-xS2 nanosheets have the optimal HER and OWS performance for x=0.050 and the optimal OER performance for x=0.075. The overpotential at current density of 100 mA/cm2 and Tafel slope are 198 mV and 44.7 mVdec-1 for HER; and they are 279 mV and 24.5 mV/dec for OER in 1 M KOH electrolyte. The electrolytic cell using Fe0.05Mo0.95S2/ CNT@CC as both cathode and anode achieves a voltage of 1.69 V at current density of 100 mAcm-2 . The bifunctional catalytic activities of the FexMo1-xS2/ CNT@CC catalyst come from the synergistic effect between FexMo1-xS2 nanosheets and CNT.