Pore‐Confined Bismuth Nanoclusters in a SrTiO ₃ @COF‐TaTp Heterojunction for Efficient H ₂ O ₂ Photosynthesis

ABSTRACT H 2 O 2 production via artificial photosynthesis represents a promising route to green synthesis, but its efficiency is often constrained by insufficient catalytic efficiency and low solar‐to‐chemical conversion. Here, we report a ternary SrTiO 3 @COF‐TaTp (TaTp = terephthalaldehyde)/bismuth nanoclusters (Bi NCs) composite, fabricated through in situ growth of an ultrathin COF‐TaTp shell on SrTiO 3 , followed by the precise confinement of ultrafine Bi NCs within the COF‐TaTp pores. This design leverages the COF‐TaTp to simultaneously broaden visible‐light absorption and establish an S‐scheme heterojunction for efficient charge separation, while the pore‐confined ultrafine Bi nanoclusters act as highly active cocatalysts to accelerate surface reactions. The optimized composite achieves a remarkable H 2 O 2 production rate of 5.76 mmol g − 1 h − 1 in pure water without sacrificial agents, substantially outperforming its individual components (SrTiO 3 : 0.15, COF‐TaTp: 0.68, SrTiO 3 @COF‐TaTp: 1.75 mmol g − 1 h − 1 ) and maintains >98.9% activity over 30 cycles, demonstrating exceptional stability. This work introduces the synergistic integration of perovskite oxides, COFs, and metal nanoclusters, offering new design principles for efficient photocatalytic H 2 O 2 synthesis.