Ru-Doped CuO/MoS2 Nanostructures as Bifunctional Water-Splitting Electrocatalysts in Alkaline Media

Molybdenum-based materials have attracted considerable attention for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) as potential alternatives to noble materials. In view of this, the present work is focused on the synthesis of mixed-phase (2H/1T) molybdenum sulfide (MoS2) using a simple facile hydrothermal method followed by its impregnation with CuO and doping with ruthenium. The nanostructured Ru-doped CuO/MoS2 (MSCR) prepared in this manner has been characterized and studied for HER and OER in an alkaline medium. The MSCR catalyst showed overpotentials of ∼198 mV, 201 mV, and 1.68 V to achieve 10 mA/cm2 current density in HER, OER, and overall water splitting. respectively. Tafel slopes of MSCR in HER (113 mV dec–1) and OER (229 mV dec–1) were found to be comparable enough to those of Pt/C and Ir/C, respectively. Such lower overpotentials and Tafel slopes arise as a consequence of proliferated electrochemical active surface area; different electronic couplings of molybdenum, copper, and ruthenium; abundant vacancies and defects; homogeneous distribution of copper oxide; higher conductivity of the structure; and unique ultrathin 3d flowerlike morphology.