This study investigates the photocatalytic oxidation of toluene using Ni-doped monolayer Bi₂WO₆ (Ni/BWO) as a photocatalyst. The introduction of Ni dopants creates cascaded active units (CAUs) consisting of unsaturated W atoms and frustrated Lewis pairs (FLPs) composed of spatially separated Bi and O atoms. Experimental characterizations and density functional theory (DFT) calculations reveal that these CAUs facilitate the efficient and controllable oxidation of C–H bonds. The catalyst with a 1.8% Ni mass fraction exhibits excellent toluene conversion rates and high selectivity towards benzaldehyde. The CAUs enable the activation of O₂ molecules and the transfer of activated oxygen species to the FLP sites, promoting the oxidation of C–H bonds. This work presents a novel strategy for enhancing the photocatalytic performance of toluene oxidation through the design of efficient CAUs.This study investigates the photocatalytic oxidation of toluene using Ni-doped monolayer Bi₂WO₆ (Ni/BWO) as a photocatalyst. The introduction of Ni dopants creates cascaded active units (CAUs) consisting of unsaturated W atoms and frustrated Lewis pairs (FLPs) composed of spatially separated Bi and O atoms. Experimental characterizations and density functional theory (DFT) calculations reveal that these CAUs facilitate the efficient and controllable oxidation of C–H bonds. The catalyst with a 1.8% Ni mass fraction exhibits excellent toluene conversion rates and high selectivity towards benzaldehyde. The CAUs enable the activation of O₂ molecules and the transfer of activated oxygen species to the FLP sites, promoting the oxidation of C–H bonds. This work presents a novel strategy for enhancing the photocatalytic performance of toluene oxidation through the design of efficient CAUs.