Fabrication of a TiO₂ Inverse Opal Film-Modified Photocatalytic Microreactor for Highly Efficient Degradation of Dyes

Two TiO₂ inverse opal films (F-TiO₂-IOF and CO-TiO₂-IOF) were synthesized on glass substrates by a limited planar rapid evaporation method, which was time- and reagent-saving, and it was easy to control their shape. The CO-TiO₂-IOF displayed a smoother mophology and better photocatalytic efficiency and stability than F-TiO₂-IOF. Over 95% of 5 mg L^-1 rhodamine B (RhB) was degraded within 120 s in the IOF-modified microreactors. A higher photocatalytic efficiency could be achieved with the synergistic catalysis of H₂O₂ and CO-TiO₂-IOF, based on which the online monitoring of RhB was realized within 2 min in the IOF-modified photocatalytic microreactor integrated with the flow cell of a UV-vis spectrophotometer. Other nitrogen-containing dyes like tartrazine and indigo carmine were also degraded in CO-TiO₂-IOF-modified microreactors with degradation rates of 83-95%.