Do Gas Nanobubbles Enhance Aqueous Photocatalysis? Experiment and Analysis of Mechanism

The performance of photocatalytic advanced oxidation must be improved in order for the technology to make jump from academic research widespread use. Research is needed on factors that cause photocatalysis become self-limiting. In this study, we introduced, first time, nanobubbles continuously into a running reactor. Synthetic air, O2, and N2 bubbles size range 40 700 nm were added reaction system comprising P25 TiO2 photocatalyst stirred aqueous solution excited by UV-A lamps, with methyl orange as target contaminant. removal was tested under conditions changing pH addition different radical scavengers. Results indicated oxygen air degradation orange—the efficiency increased 58.2 ± 3.5% (N2 aeration) 71.9 0.6% (O2 aeration). Dissolved (DO) 14.93 0.13 mg/L achieved using O2 comparison 8.43 0.34 without aeration. photodegradation decreased 70.8 0.4% 53.9 0.5% 2 10. Experiments scavengers showed O2? main reactive species highly dissolved conditions, which also accounted observation at higher pH. However, photocatalyst, alone did not improve orange, increase only photolysis. These experiments show can act environmentally friendly catalysts boosting water treatment systems.