Heterogeneous interface-triggered electronic reconfiguration of cobalt-based sulfide electrocatalysts modified by coupling CeO2 for H2 production

Abstract

It is pivotal but difficult to formulate bifunctional catalysts for electrochemical water splitting that are earth-abundant. Coupling CeO2 can not only improve the sluggish intrinsic OER activity of Co3S4 but also ameliorate the overall catalytic activity. Herein, vertically hierarchical amorphous Co3S4-CeO2 (Co3S4 and CeO2 were used as the main components, so it’s named Co3S4-CeO2) porous nanorods arrays were prepared via relatively facile anion intercalation enhanced electrodeposition on nickel foams (NFs) and following high-temperature vulcanization. Moreover, several characterization techniques, including XRD, were used to demonstrate that the Co3S4-CeO2 heterostructure was successfully synthesized. In both HER and OER, the Co3S4-CeO2 electrode showed remarkable electrochemical performance in alkaline solutions, only 120 mV overpotential and 280 mV drive are needed for the current densities of 10 mA•cm−2 in HER and 50 mA•cm−2 in OER, respectively. The Co3S4-CeO2 electrodes used as the anode and cathode in the double electrode alkaline electrolytic cell enable a value of 1.55 V at 10 mA•cm−2, also the electrolytic cell can sustain for at least 40 h without obvious attenuation. This work offers a straightforward technique for generating heterogeneous nanostructures as well as strong proof that CeO2 can be efficaciously coupled.