Boosting Photocatalytic Dissolution of Platinum Group Metals via a BiOCl/TiO 2 Heterojunction

The recovery of platinum group metals (PGMs) from secondary resources is essential for resource sustainability, yet their dissolution remains heavily dependent on harsh reagents such as aqua regia owing to extreme chemical inertness. Photocatalytic oxidation under ambient conditions offers a green and mild alternative, but conventional TiO 2 photocatalysts suffer from severe charge recombination, leading to sluggish kinetics for the most inert PGMs. Herein, we construct a BiOCl‐modified TiO 2 (BiOCl/TiO 2 ) composite by integrating bulk BiOCl with TiO 2 nanoparticles at a Bi:Ti molar ratio of 10:100. Under UV light, the platinum (Pt) dissolution rate of the BiOCl/TiO 2 catalyst was 33.5 times that of bare TiO 2 , while the dissolution rates of rhodium (Rh) and palladium (Pd) were also substantially enhanced. Photoelectrochemical measurements and radical trapping experiments confirmed that the heterojunction suppresses electron‐hole recombination and promotes the generation of superoxide (O 2 •− ) and chlorine (Cl • ) radicals, thereby overcoming the kinetic barrier for PGMs’ dissolution. This work not only presents a highly efficient photocatalytic system for mild PGMs leaching but also broadens the application of BiOCl‐based heterostructures to sustainable metal recovery.