Conducting polymer-templated and nonnoble metal doped MoSe2 hybrids as bifunctional electrocatalysts for overall water splitting

Abstract

Transition metal dichalcogenides (TMDs) are potential candidates for electrocatalytic applications due to their unique structures and intrinsic properties. In this work, the systematic synthesis of conducting polymer-templated and nonnoble metal-doped MoSe₂ hybrids was carried out using a facile hydrothermal method. Integrating conductive polyaniline, as a conductive polymer, with MoSe₂ nanosheets (MoSe₂@PANI) as well as transition metal (Co, Ni or Fe) doping provided more active sites for both H⁺ and OH^– adsorption, resulting in enhanced hydrogen and oxygen evolution performance. The Co-doped MoSe₂@PANI hybrid catalyst exhibited enhanced bifunctional electrocatalytic activity for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in alkaline electrolytes, where Co-doping as well as polyaniline addition played key roles in boosting the HER/OER activity. As a result, the Co-doped MoSe₂@PANI catalyst exhibited overpotentials of 196 mV and 385 mV at a current density of 10 mA cm⁻² for the HER and OER, respectively. When Co-doped MoSe₂@PANI was applied as a bifunctional electrocatalyst for overall water splitting, a potential of 1.82 V was needed to achieve a current density of 10 mA cm⁻². Moreover, the Co-doped MoSe₂@PANI catalyst displayed good stability for long-term cycling. This work provides new insight into the design of metal-doped TMD/conducting polymer-based materials for electrocatalytic applications, including water electrolysis.