Bismuth titanate modified and immobilized TiO₂ photocatalysts for water purification: broad pollutant scope, ease of re-use and mechanistic studies

Abstract

Bi4Ti3O12–TiO2 on glass beads photodegrades pollutants including consumer-product precursors, pesticides, drugs and explosives.

Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution

“…Also, removal efficiency of metronidazole by photolysis alone was 45% after 90 minutes and increased to 95% in the presence of photocatalyst. The synergy value of removal efficiency of metronidazole was obtained 95% by the photocatalytic degradation indicating that the combination of photolysis and photocatalysis processes can degrade selected pollutants which may be attributed to the UV light with high energy that can easily penetrate to ZnO nanoparticles and generate more hydroxyl through mentioned reactions (34,36,37).…”

“…(7 and 8). At low pH, the high concentration of protons in solution prevents the formation of hydroxyl radicals (7,8,36,39). Actually, the amounts of hydroxyl radicals increase by increasing the reaction time.…”

Sequential ionic layer adsorption reaction formation of LaVO4–TiO2 nanocomposites for photocatalytic water treatment

“…While 4-CP is generally accepted as a good model pollutant, it is worthwhile to note that different pollutants often exhibit different degradation rates under identical conditions. 44 Therefore, while the performance described herein gives a good indication of the activity of the LVO-TiO 2 composite, it should only be construed as such.…”

Field testing of low-cost titania-based photocatalysts for enhanced solar disinfection (SODIS) in rural India

“…In previous studies, we have developed successful photocatalysts based on TiO 2 , including C-TiCl 4 -TiO 2 , 21 BiVO 4 -TiO 2 , 22 BiOI-TiO 2 23 and Bi 4 Ti 3 O 12 -TiO 2 . 24,25 These offer enhanced photocatalytic activity over un-modified titania and, thus far, the most promising of these under laboratory conditions is the Bi 4 Ti 3 O 12 -TiO 2 co-catalyst system (BTO-TiO 2 ), attributed to its good stability and the presence of the heterojunction band architecture, which can reduce the extent of charge recombination. After demonstrating the BTO-TiO 2 co-catalyst system as a layer coated on glass beads, 24 it was imperative that field tests should be conducted.…”

“…We use photocatalyst immobilised on beads, rather than suspended powder, in our studies to ensure the system is appropriate for rural use without the need for complicated separation processes. Rather than a rigorous quantitative analysis of the comparison between TiO 2 and bismuth titanate, which already exists in the literature, 25,26 this study provides an assessment of catalyst performance when used outdoors under natural sunlight to treat contaminated water of practically useful volumes, when coupled with a simple and inexpensive SODIS-type reactor set-up, as well as useful insights into how best to conduct such studies.…”