Interfacial Heterojunction Electronic Modulation on RuSe2@NiFeLDH Heterostructures for Water Splitting

It is challenging to create an electrocatalyst for water electrolysis that is long-lasting, highly efficient, and inexpensive for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this work, we have synthesized an ordered NiFe-layered double hydroxide (LDH)/RuSe2 heterostructure for electrochemical water splitting reaction. The synthesized heterostructure electrode NiFeLDH/RuSe2 exhibits exceptional HER and OER performance as it produces a current density of 10 mA cm–2 at 60 and 268 mV overpotential, respectively. Very low Tafel slope values of 70 and 69 mV dec–1 for the HER and OER, respectively, imply a fast charge transfer process. Additionally, for the HER and OER processes, even after 40 h, the synthesized NiFeLDH/RuSe2 heterostructure electrodes demonstrate long-term endurance. Insights into interfacial electron transfer are provided by Mott–Schottky experiments, which signifies the creation of the p–n junction in NiFeLDH/RuSe2, which helps in the transition of electrons from n-type NiFeLDH to p-type RuSe2. The formation of the heterojunction enhances the active sites to adsorb H+ and OH– ions, and hence better OER and HER processes are achieved. Transmission electron microscopy clearly depicts the formation of different interfaces at multiple points that was assigned to the interplanar distance of NiFeLDH and RuSe2.