Defect-rich CoMoS nanosheets on PANI nanowires as excellent hybrid electrocatalyst for water splitting

Developing economic, efficient, and stable bifunctional electrocatalysts for producing oxygen and hydrogen simultaneously remains challenging. Here, we design and fabricate vertically aligned cobalt molybdenum sulfide (CoMoS) nanosheets on a conductive polyaniline (PANI) nanowire on nickel foam (NF) by a one-step solvothermal synthesis. The hybrid CoMoS-PANI array demonstrates low overpotentials of 250 and 98 mV, to achieve a current density of 10 mA cm(-2) in an alkaline solution, for the oxygen and hydrogen evolution reactions, respectively. As an electrolyzer for overall water splitting, CoMoS-PANI/NF, as both the anode and the cathode, exhibits a current density of 10 mA cm(-2) at a low cell voltage, 1.58 V. Furthermore, good stability for 50 h at a current density of 20 mA cm(-2) during overall splitting suggests that CoMoS-PANI can be promoted as a highly efficient and stable bifunctional catalyst. The upgraded electrocatalytic activity of CoMoS-PANI can be ascribed to its defect-rich structure, the exhibition of the PANI nanowire to effective electron transfer, and the ample of active catalytic sites provided by the synergistic effect of the hybrid structures. This work is a promising step towards the design and exploration of hybrid materials as excellent electrocatalysts for renewable energy generation. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, vertically aligned cobalt molybdenum sulfide (CoMoS) nanosheets were synthesized on a conductive polyaniline (PANI) nanowire to fabricate a CoMoS-PANI nanosheet array. The nanosheet array showed low overpotentials for oxygen and hydrogen evolution reactions in an alkaline solution, achieving high current densities. As an electrolyzer for water splitting, the CoMoS-PANI nanosheet array exhibited good stability and high efficiency. The improved electrocatalytic activity of CoMoS-PANI was attributed to its defect-rich structure, effective electron transfer through the PANI nanowire, and the abundant catalytic sites provided by the hybrid structure.