Study on oxidant strengthening photocatalytic degradation of DMF over TiO₂ fiber catalyst

Oxidant strengthening the degradation of DMF aqueous solution was investigated when TiO₂ fiber is used as the photocatalyst. When the UV light was absent, ozone per se could not make DMF degrade, which proves that DMF is a stable substance. But ozone could increase obviously photocatalytic degradation rate of DMF in O₃/TiO₂(F). Under the same reaction condition, photocatalytic degradation rate and speed of DMF in O₃/TiO₂(F) was almost 1.5 times and 2 times higher than that in air/TiO₂(F) and H₂O₂/TiO₂F) respectively. COD analysis showed DMF was almost mineralized completely when the reaction was carried out for 120 min. Through Hinsberg test secondary amine was proved as one of intermediates in the process of DMF photocatalytic degradation. Rise of pH value of reaction solution also showed that amine was produced in the photocatalytic reaction process. Degradation speed of DMA in O₃/TiO₂(F) was higher than that in air/TiO₂(F). The increasing degradation rate and speed of DMF was mainly catsed by fast degradation of secondary amine in the process of DMF photocatalytic degradation in O₃/TiO₂(F).