Construction of ZnAl LDH-Derived Sulfides with Etching Modification to Trigger Photocatalytic H2 Production and Degradation Oxidation

Constructing novel functional photocatalysts represents a promising approach to optimize the energy band structure and facilitate the separation of photogenerated carriers. Layered double hydroxides (LDHs) exhibit notable advantages in photocatalysis due to the exceptional photoelectrochemical properties and elevated number of active surface atoms. However, an unsuitable band gap and limited carrier migration have inhibited their development in photocatalysis. Herein, we propose a novel in situ topological vulcanization strategy for optimizing the photocatalytic activity of ZnAl LDH-derived sulfides (ZnAlS_x). The subsequent etching process via a 1 M NaOH solution was introduced to construct the ZnS_x photocatalysts. Then, the crystallinity of the crystals was enhanced by etching to further improve the catalytic activity and stability of ZnS_x. The as-synthesized ZnS_x shows an excellent photocatalytic hydrogen production rate (11.89 mmol/g/h) and tetracycline degradation efficiency (91.94%) under light illumination, and its hydrogen evolution efficiency is approximately 176 and 2 times greater than that of ZnAl LDH and ZnAlS_x, respectively. The characterization and density functional theory (DFT) analysis confirmed that the surface electronic properties and energy band structure of ZnAl LDH were significantly optimized after experimental treatment, resulting in enhanced carrier separation and photooxidative reduction capacity. Combining in situ topological vulcanization and etching to realize the functional conversion of ZnAl LDH provides promising insights into the construction of high-performance, low-cost photocatalysts.