We herein report the synthesis and photoredox catalysis of a mononuclear zinc-introduced lacunary disilicoicosatungstate TBA₇[{Zn(CH₃CN)}(γ-SiW₁₀O₃₄){γ-SiW₁₀O₃₂(CH₃CONH)}(μ-O)₂] (II, TBA = tetra-n-butylammonium). POM II showed efficient photocatalytic activity in the selective deoxygenation of pyridine N-oxides under visible light irradiation (λ > 400 nm).