CoNi-LDH/TiOx type-II heterojunction via atomic layer deposition for enhanced photocatalytic hydrogen evolution

Manipulating internal charge migration pathways by regulating the electron distribution is an effective strategy to enhance photogenerated carriers separation and migration, which is critical for advancing photocatalytic water reduction technology. Using zeolitic imidazolate framework-67 (ZIF-67) as the precursor, chemical etching facilitates the growth of uniform and dense CoNi-layered double hydroxide (CoNi-LDH) nanosheets along the cubic shell, ultimately forming CoNi-LDH hollow nanocages. Additionally, A type-II heterojunction with precisely controlled TiO x thickness, denoted as CoNi-LDH/TiO x , was engineered using atomic layer deposition (ALD). This technique takes the advantage of the unique self-limiting reactions of ALD to achieve atomic-level thickness control, which is crucial for the spatial separation of photogenerated carriers. Consequently, this promotes the migration efficiency of these carriers. The optimized CoNi-LDH/TiO x photocatalyst achieved a hydrogen production rate of 5.239 mmol g −1 h −1 , showing a fourfold increase in efficiency. These results provide valuable insights for future research and development in the field of photocatalytic hydrogen production, particularly when utilizing LDH-based catalysts.