Simultaneously Enhancing Activity and Stability of Perovskite by Grafting Dodecylphosphonic Acid for Selective Photooxidation of C(sp 3 )–H

Perovskite halides, a promising class of photocatalysts for the selective oxidation of C(sp 3 )H bonds, face critical challenges for practical implementation. Their inherent chemical instability under illumination and humid conditions, primarily driven by halide ion migration, remains a major obstacle to real‐world application. In this work, dodecylphosphonic acid (DDPA)‐grafted Cs 3 SbBiBr 9 (CSBB) photocatalysts were achieved as an efficient and stable aerobic oxidation photocatalyst. The formation of strong MOP bonds between DDPA and CSBB directs charge transfer and suppress Br – migration. Concurrently, the long alkyl chain (C 12 ) creates a hydrophobic surface, enhancing toluene adsorption while effectively repelling water and preventing perovskite hydrolysis. Remarkable toluene conversion rate of 21.648 mmol g −1 and 85% selectivity towards benzaldehyde is realized, which is 3.8 times that of pristine CSBB. Moreover, the stability of CSBB was significantly enhanced after DDPA modification.