Facile Tuning Oxygen Vacancies and Ti 3+ Level of MIL‐125(Ti)‐Derived Pd/TiO 2 ‐C for Photocatalytic Suzuki Reaction

ABSTRACT The application of titanium dioxide (TiO 2 ) in photocatalysis is restricted by issues such as its wide band gap, inability to absorb visible light, and easy recombination of photogenerated carriers. To enhance the photocatalytic activity of TiO 2 , the formation of an [O v ·Ti 3+ ] + impurity level through Ti 3+ ‐doping is an effective strategy. In this study, a highly efficient photocatalyst Pd/TiO 2 ‐C Act250 , featuring high concentrations of oxygen vacancies and Ti 3+ level, was successfully synthesized by the initial activation of MIL‐125(Ti) at 250°C, followed by wet impregnation with Pd (NO 3 ) 2 and subsequent pyrolysis. The activation temperatures significantly affected the content of oxygen vacancies and Ti 3+ /Ti 4+ ratios in the catalyst. The activated catalysts Pd/TiO 2 ‐C Act showed increased oxygen vacancies and Ti 3+ /Ti 4+ ratios, reaching the highest values upon activation at 250°C. The high oxygen vacancy concentration and Ti 3+ /Ti 4+ ratio broadened the light‐absorption range and promoted the efficient separation of electron–hole pairs, ultimately resulting in superior photocatalytic performance, with a catalyst in low Pd concentration (0.008 mol%), for the Suzuki–Miyaura reaction.