In Situ Generated Ag–Ni Alloy Assisted Nickel Ferrite Dual Functional Electrodes for Electro- and Photocatalytic Water Splitting

Industrial applications demand dual active photo- and electrocatalysts for the production of sustainable and clean hydrogen via the conventional water splitting process. In this scenario, we developed Ag–NiFe2O4/NiP (AgNF/NiP), an electrode for enhancing both electrocatalytic and photocatalytic performance. The sol–gel method enabled the synthesis of Ag–NiFe2O4, which was then coated with NiP using an electroless deposition process, leading to the in situ generation of a Ag–Ni alloy. The Ag–Ni alloy formation increased the intrinsic electrical conductivity due to the synergic interaction between Ag and Ni, which facilitated the photocatalytic HER and electrocatalytic OER. The developed electrode displayed a reduced charge transfer resistance Rct at OCP of 381 Ω and high electrochemical active surface area of 24.75 cm2, which provided an enormous number of active sites. The OER performance of the AgNF/NiP electrode was evaluated by LSV analysis. The electrode possessed a low overpotential value of 253 mV and low Tafel slope value of 66.8 mV dec–1. Chronoamperometry at different potentials for 4 h confirmed the good stability of the electrode. The photocatalytic water splitting analysis evidenced that the catalytic electrode possessed high water splitting potential even after 5 cycles of continuous operation using natural sunlight, generating 1.96 mmol cm–2 H2 in 5 h.