Experimental and theoretical insights into LDH based on iron for photoelectrochemical water splitting

Abstract

Abstract This study presents a novel layered double hydroxide (LDH) composite consisting of Mg/Fe and Ca/Fe-LDH layers, synthesized via a co-precipitation method, aimed at enhancing hydrogen production from solar energy. The composites have bandgaps of 2.01 eV and 2.81 eV, respectively, making them ideal for photoelectrochemical (PEC) water splitting. The study demonstrates that using Mg/Fe-LDH can significantly increase the rate of hydrogen generation, achieving a catalytic H2 production rate of 2542.36 mmol/h·cm2 and a catalytic efficiency of 56.39% at 460 nm and 59.85% at 490 nm. ABPE achieves maximum peaks of 5.75% at 0.92 V and 5.33% at 0.4 V, setting new standards for LDH-based photocatalysts. The research also examines the effects of temperature and monochromatic light on PEC performance, thermodynamic parameters, electrochemical surface area, Tafel slopes, and hydrogen evolution kinetics. The LDH photoelectrode’s stability and reusability reveals its long-term application potential, providing fresh insights on improving PEC methods for industrial-scale water splitting in sunlight. Also, this is further corroborated by Density Functional Theory (DFT). This distinctive methodology was selected for the design of LDH nanomaterials for hydrogen-generation applications.