Exploring Flower‐Structured Bifunctional VCu Layered Double Hydroxide and its Nanohybrid with g‐C3N4 for Electrochemical and Photoelectrochemical Seawater Electrolysis

Abstract Seawater electrolysis holds great promise for sustainable green hydrogen generation, but its implementation is hindered by high energy consumption and electrode degradation. Two dimensional (2D) layered double hydroxide (LDH) exhibits remarkable stability, high catalytic activity, and excellent corrosion resistance in the harsh electrolytic environment. The synergistic effect between LDH and seawater ions enhances the oxygen evolution reaction, enabling efficient and sustainable green hydrogen generation. Here, we report a synthesis of low cost, novel 2D Vanadium Copper (VCu) LDH first time in the series of LDH's as a highly efficient bifunctional electrocatalyst. The electrochemical (EC) and photoelectrochemical (PEC) study of VCu LDH and VCu LDH/Graphite Carbon Nitride (g‐C 3 N 4 ) nanohybrid was performed in 0.5 M H 2 SO 4 (acidic), 1 M KOH (basic), 0.5 M NaCl (artificial seawater), 0.5 M NaCl+1 M KOH (artificial alkaline seawater), real seawater and 1 M KOH+real seawater (alkaline real seawater) electrolyte medium. It was found that VCu LDH shows a remarkable lower overpotential of 72 mV hydrogen evolution reaction (HER) and 254 mV oxygen evolution reaction (OER) at current density of 10 mA/cm 2 under alkaline real seawater electrolysis exhibiting bifunctional activity and also showing better stability.