Developing a novel photothermal catalyst for efficient mineralization of volatile organic compounds (VOCs) is of great significance to control air pollution. Herein, for the first-time, a spinel Cu_1.5Mn_1.5O₄ nanomaterial with enhanced surface lattice oxygen activation was successfully obtained by a novel light-driven in situ reconstruction strategy from its precursor (CuMnO₂) for efficient toluene mineralization. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) analyses confirm that the CuMnO₂ phase was converted into spinel Cu_1.5Mn_1.5O₄ phase under full spectrum light irradiation. Ultraviolet–visible–near infrared ray (UV–vis–NIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) analysis, and density functional theory (DFT) calculations determine that the strong near-infrared absorption ability and low dissociation energy of oxygen bond in Cu_1.5Mn_1.5O₄ are beneficial to its surface lattice oxygen activation. Furthermore, O₂-temperature programmed desorption (TPD) and in situ diffuse reflectance infrared transform spectroscopy (DRIFTS) further indicate that the surface lattice oxygen of the Cu_1.5Mn_1.5O₄ is easily activated under light irradiation, which can promote ring opening of toluene. This research endows a new design of photothermal nanomaterial with enhanced lattice oxygen activation for deep oxidation of VOCs.