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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]

It has been partially shown that salicylic acid (SA) as an imprinting molecule can produce better photocatalytic effect, while the contribution of SA as a molecular imprinting and degradation substrate is not clear. Herein, SA-TiO2 was prepared by a one-step molecular imprinting method using SA as the imprinting molecule and tetra-n-butyl titanate as the precursor, which was analyzed by XRD, UV–Vis, SEM, TEM-EDS, XPS, PL, FT-IR, EIS, and photocurrent response. The results shown that 1.5SA-TiO2 had the best electrochemical properties and therefore the best photoelectric effect. Moreover, the decolorization rates of SA within 30 min were 49.25% and 62.69% for TiO2 and SA-TiO2, respectively, indicating that the synthesized SA-TiO2 had better photocatalytic performance and could be applied in future scenarios for the efficient degradation of SA wastewater. [ABSTRACT FROM AUTHOR]

There is an enlightening phenomenon in nature where mussels can purify water following swallowing microorganisms, debris, gravel, etc. Inspired by this phenomenon, we simulated the shell-pearl structure of a clam, and developed a unique method to synthesize Bi 2 O 3 intercalated bismuth titanate and molecularly imprinted TiO 2 microbead composites. Salicylic acid (SA) as an organic molecule (also target pollutant) plays a key role in the protection and formation of Bi 2 O 3 , which is key to obtaining the structure of mussel shell. The open shell-pearl bionic structure enables efficient transport of excited electrons across a variety of surface interfaces, while suppressing the complexity of photogenerated carrier that drives photocatalytic efficiency. Results show that the synthesized shell-pearl type catalyst achieved 92.54% degradation efficiency of salicylic acid under 30 min UV irradiation, which is 1.97 times higher than that of TiO 2. The high degradation efficiency indicate that pearl type catalyst has promising applications in future environmental purification as well as human health. [Display omitted] • Successful synthesis of open shell-pearl structure photocatalyst. • The synthesized catalyst achieved 92.54% degradation efficiency of salicylic acid. • Imprinted molecules proved to have a protective effect. • The new structure-activity relationship has been fully demonstrated. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) photocatalysis is a popular and promising technology in water treatment, but the performance evaluation usually depends on expensive equipment. In this study, using a smartphone for colorimetric detection, a self-invented method based on paper and microtubes (PMTs) is proposed to test the photocatalytic performance of TiO2. Firstly, the study has identified that PMTs achieved a correlation coefficient of above 0.9 between the greyscale values and concentrations during the physical process of different color dyes (i.e., rhodamine B (RhB), reactive yellow (RY), methylene blue (MB), and mixtures of the two or three dyes). The results indicate that when the principle of solution color follows the CMYK (Cyan, Magenta, Yellow, Black) color model, its photo color on white paper background conforms to the RGB (Red, Green, Blue) color model. Compared to the results obtained from the absorbance method, the PMTs method showed high reliabilities up to 99.36% on the monitoring of the photocatalytic process of the different dye solutions. Interestingly, the colorless solution of salicylic acid (SA) could also be analyzed by the PMTs after complexed with Fe(III) ion to develop a purple solution. These results suggest that the PMTs could be an alternative analysis method to evaluating physical and chemical reaction processes when the high-tech analysis equipment is unviable. [ABSTRACT FROM AUTHOR]