Synthesis of Self‐Assembled Porous Naphtalene Dianhydride‐TiO₂ Composites for Photocatalytic Hydrogen Production

Abstract Conversion of solar energy to clean energy via naphthalenetetracarboxylic dianhydride (ND)‐based organic semiconductors represents a topic of research. Nonetheless, efforts in this area are challenging due to the rapid recombination of photogenerated electron‐hole (e‐h) pairs arising from over‐accumulation. Herein, various n‐type hybrid photocatalysts, ND‐TiO₂ (x:y) (x and y represent the ratios of ND and TiO₂, respectively), featuring excellent visible‐light responsiveness, fast separation and migration ability of charge carriers, and permanent porosity, are constructed via a sol–gel self‐assembly approach. The rational assembly of ND with TiO₂ not only effectively inhibits the problematic overgrowth of ND but also enables the composites with excellent visible‐light responsiveness, and facilitates the separation and migration of charge carriers, thus resulting in greatly improved photocatalytic H₂ evolution performance. The optimized composite ND‐TiO₂(1:10) with 0.38 wt% Pt nanoparticle loading presents a maximum hydrogen‐evolution rate of 3.23 mmol·g⁻¹·h⁻¹, with extraordinary TON (2446) and TOF (163.1 h⁻¹), which are much higher than ND (0.031 mmol·g⁻¹·h⁻¹) and TiO₂‐Colloid (0.027 mmol·g⁻¹·h⁻¹) counterparts. In addition, the underlying photocatalytic mechanism is well established through comprehensive experiments and computational studies.