非现建制知识库

In this paper, a new photocatalyst, ZnFe₂O₄ spinel powder without any noble metal loading, was studied in a dispersion system irradiated with visible light and under different conditions. The typical results were that the hydrogen generation rate was 0.025 ml h⁻¹ (mg catalyst)⁻¹ in 25 ml of 0.1 M sulfide solution containing 25 mg ZnFe₂O₄ powder at pH 12. The u.v.—vis and XRD spectra show that the ZnFe₂O₄ powder absorbs visible light and has a spinel structure. The dependences of H₂ production rate on pH and concentration of sulfide were also studied. ZnFe₂O₄ spinel powder has a good performance for H₂ S photodecomposition at pH 8–12. The photocatalytic activity of ZnFe₂O₄ is much higher than that of ZnS-CdS under the same conditions.