Incorporation of polyaniline and cobalt deposition to tune electrochemical performances of MoSe2 catalysts for overall electrochemical water splitting

The development of affordable and plentiful electrocatalysts for electrochemical water splitting process has received considerable interest in recent years. Two-dimensional transition metal dichalcogenide (TMD)-based materials are highly promising catalysts for electrochemical water splitting because of their tunable physical and electrical properties. This study presents molybdenum diselenide (MoSe2) hybrid nanostructures prepared via a hydrothermal method in the presence of polyaniline (PANI) conductive supports with different morphologies. Different PANI supports were prepared via oxidative chemical polymerization in the presence of different surfactants. The MoSe2@PANI nanostructures obtained were also modified with cobalt by electrodeposition approach to enhance the electrocatalytic performance of the resulting catalysts. The resulting cobalt-modified MoSe2@PANI-sodium dodecyl sulphate (SDS) (Co–MoSe2@PANI-SDS) catalyst exhibited low overpotentials 339 mV and 134 mV at a current density of 10 mA cm−2 with low Tafel slopes 51 mV dec−1 and 110 mV dec−1 for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. The improved performance of Co–MoSe2@PANI-SDS can be attributed to the incorporation of PANI-SDS as an ideal conducting support and cobalt interactions with both the MoSe2 and the conducting polymer. This work would be insightful in developing new electrocatalysts with bifunctional activities for efficient production of hydrogen through water splitting. •Incorporation of a surfactant into the polyaniline enhanced its efficiency as a conductive support for the MoSe2 catalyst.•Cobalt-modification of MoSe2@PANI-SDS nanostructure enhanced the active sites of MoSe2 for electrochemical water splitting.•Co-modified MoSe2@PANI-SDS was demonstrated to be used as bifunctional catalyst in electrochemical water splitting.•Co-modified MoSe2@PANI-SDS catalyst exhibited overpotentials of 134 and 339 mV at 10 mA cm−2 for HER and OER, respectively.