Insights into the evaluation of photocatalytic quenching experimental results by degrading a dye.

In this study, Bi2Ti2O7−TiO2 was synthesized in a single step via the sol–gel method, after which its photocatalytic properties and mechanisms were investigated. Moreover, our study proposed and evaluated the use of salicylic acid (SA) and basic magenta (BM) as model contaminants in quenching experiments. When SA was used as the model pollutant, the reaction rates showed negative values. Therefore, the experimental results failed to truly and effectively reflect the actual photocatalytic performance of Bi2Ti2O7−TiO2. However, when BM was used as the model pollutant, the reaction rates were all positive and the experimental results were far more descriptive. Hydroxyl radicals (·OH), superoxide radicals (·O2−), and photogenerated holes (h+) all contribute to the photocatalytic activity of Bi2Ti2O7-TiO2, with ·OH making the largest contribution. Collectively, our findings can serve as a basis to improve the accuracy and efficiency of future photocatalytic mechanism experiments, which could bring great economic benefits. [ABSTRACT FROM AUTHOR]