NiMoSe/Ti3C2Tx MXene @ CC as a highly operative bifunctional electrocatalyst for hydrogen and oxygen evolution reactions in an alkaline medium.

Low-cost and highly efficient cathode and anode materials are required for proton exchange membrane and alkaline water electrolyzers. The present work demonstrates the development of a bifunctional cathode and anode material for hydrogen and oxygen evolution reactions (HER/OER) in an alkaline environment. The bimetallic Ni–Mo selenide is fabricated over the MXene (Ti 3 C 2 T x) grown over the activated carbon fibers by an inexpensive, simple one-step and eco-friendly approach. The electrocatalyst NiMoSe/Ti 3 C 2 T x @CC is developed via a hydrothermal method wherein NiMoSe is observed to grow highly dense nanoporous structure as confirmed by various characterization techniques. Highest activity for HER is observed using NiMoSe/Ti 3 C 2 T x @CC with only overpotential of 203 mV at 10 mA cm−2 with low Tafel slope (45 mV dec−1). The catalyst is also proven to support OER activity with requirement of 320 mV as overpotential at 10 mA cm−2, thus better than commercial IrO 2 (η 10 = 380 mV). The Tafel slope obtained by NiMoSe/Ti 3 C 2 T x @CC for OER is found to be minimum (189 mV dec−1) along with a very low charge transfer resistance (3.04 Ω) and high electrochemical surface area (0.0378 mF cm−2). The NiMoSe/Ti 3 C 2 T x @CC is found to be highly stable for HER/OER with 1000 LSV cycles. The work highlights the development of a cost-effective and efficient Ti 3 C 2 T x (MXene) based bifunctional electrocatalyst for oxygen evolution and hydrogen evolution reactions (OER/HER) in an alkaline medium (1 M KOH). The bimetallic Ni–Mo selenide is fabricated over the MXene on the activated carbon fibers by an inexpensive, simple, one-step hydrothermal method. The highly dense nanoporous structure shows an overpotential of 203 mV at 10 mA cm−2 for HER in alkaline medium. The corresponding overpotential for OER is 320 mV which has been found better than commercial IrO 2 catalyst (η 10 = 380 mV). In addition, NiMoSe/Ti 3 C 2 T x @CC bears a high electrochemically active surface area (0.0378 mF cm−2), low charge transfer resistance (3.04 Ω), and high stability (1000 LSV cycles) for both OER and HER. [Display omitted] • Bifunctional NiMoSe/Ti 3 C 2 T x @CC was synthesized via one step hydrothermal route. • Overpotential (η 10) for HER was found to be 203 mV. • For OER, overpotential (η 10) was found 320 mV, better than commercial IrO 2. • 1000 LSV cycle and 30 h stability was conducted for HER and OER. [ABSTRACT FROM AUTHOR]