Polyoxometalates (POMs), renowned for their robust multielectron transfer capabilities, are utilized as photocatalysts. A Cu&POM based complex comprising H₃PMo₁₂O₄₀ (PMo₁₂) and 1,10-phenanthroline has been structured into a supramolecular framework through hydrogen bonding and π–π interactions. This complex demonstrates exceptional photocatalytic efficacy in the oxidation of toluene and the photodegradation of metronidazole. The oxidation of toluene with Cu-PMo₁₂ achieved a yield and selectivity of 100% under low energy conditions, producing unprecedented results and demonstrating outstanding stability in cycling tests. Photodegradation of metronidazole using Cu-PMo₁₂ achieved a degradation rate of 0.178. This work could facilitate the design and synthesis of novel Cu&POM based complexes with superior photocatalytic activities.