Molecular oxygen activation (MOA) plays a crucial function in various oxidation reactions. Nonetheless, facile, continuous and efficient MOA remains challenging. Herein, we have successfully constructed recyclable CuⅠ-Ov-Mn sites (Ov: oxygen vacancy) for MOA by incorporating Cu single atoms in MnO2 matrix. The localized photogenerated electron at CuⅡ site drives the generation of electron-rich CuⅠ species and an adjacent photoinduced Ov, which possesses stronger O2 affinity and affords a durable O2 activation site. The CuⅡ/CuⅠ cycle accelerates the separation of charge carriers to supply adequate photogenerated electrons and assures the renewability of photoinduced Ov, thus realizing rapid and sustained O2 activation and generating abundant monatomic oxygen ions (O-). Consequently, Cu-MnO2 catalyst performed extraordinarily high activity in O2-involved reactions. For instance, in toluene oxidation, toluene conversion reached as high as 96 %, comparable to that on the state-of-the-art supported Pt catalysts. This work will bring more possibilities for modulating the O2-involved oxidative reactions.