A stable visible light-driven metallogel-based photocatalyst for dye removal

A metallogel containing Cr3+ ions has been prepared by means of the solvothermal method. This metallogel is observed to be stable on standing at room temperature at least for 3 months and possesses excellent chemical stability in aqueous solutions with pH scale ranging from 1 to 10. The value of the band gap for this xerogel obtained is 1.72 eV, and this gel is suitable for photocatalytic measurements. Interestingly, this metallogel possesses high catalytic activities toward the degradation of dyes under LED and natural light at room temperature, indicating this metallogel is active for the photodegradation of dyes. Furthermore, this xerogel can be reused at least four times without obviously decreasing in catalytic activity. To the best of our knowledge, this would be the first method where these dyes are degraded by the gel-based material. A stable metallogel can firstly act as an excellent dye degradation agent by the gel-based material under visible light.