Trimetallic Ni_xCo_yAl_z LDH-Modified g-C₃N₄ with Influential Effects of M²⁺/M³⁺ (Ni/Co) Active Centers for Stimulating Photocatalytic Hydrogen Production

Developing a highly efficient photocatalytic system is a sustainable approach for generating clean hydrogen to address the proliferating consumption of primary energy sources. In this study, trimetallic Ni_xCo_yAl_z LDH with a controlled surface morphology was designed and incorporated with g-C₃N₄ to construct a highly efficient S-scheme electron transfer system. The coeffects of regulating the cationic composition of LDH and the dominance of Ni, Co, and Al as active centers in the LDH framework were investigated. Configuring the cationic composition of Ni_xCo_yAl_z LDH with the M²⁺/M³⁺ interaction results in variations in the band gap value and photonic characteristics, influencing its performance efficiency and light absorption capability. The optimal design of Ni₁Co₁Al₁ LDH exhibited exceptional photochemical efficiency with stable structural formation and enhanced reduction ability, significantly improving photocatalytic hydrogen production. The optimal electronic structures of trimetallic Ni₁Co₁Al₁ LDH enable the efficient construction of an S-scheme system in a binary nanocomposite. The S-scheme charge transfer system offers spatial separation of photogenerated charges and suppresses their recombination, resulting in maximal hydrogen production, reaching up to 338 μmol g^-1 h^-1 in 10-2NiCoAlCN. The photocatalytic activity test over consecutive cycles revealed a stable and gradual hydrogen yield, demonstrating good chemical stability. This study explored the intercorrelation between the cationic effects on the photocatalytic properties of Ni_xCo_yAl_z LDH, which can serve as valuable insight for further research in this field.