Improving the Catalytic Performance of M-Tio2@Cds Via Response Surface Methodology to Accommodate Light-Saturated and Non-Light-Saturated Reactions

Abstract

The traditional catalyst performance evaluation is conducted under high light intensity, and the differences in e--h+ pair recombination rates under different light intensities may result in the preferred catalyst being unable to be extended to other light sources of varying intensities. We used response surface methodology (RSM) to compare the performance catalysts under two optimization processes with tetracycline degradation rate and photon fluence as responses. The m-TiO2@CdS was evaluated by XRD, SEM, TEM, XPS, and UV-Vis-DRS. The preparation process of m-TiO2@CdS was optimized by RSM (precursor ratio, hydrothermal time and temperature). The proposed tetracycline degradation rate and photon fluence optimization model showed satisfactory correlation between predicted and experimental results. The tetracycline degradation rates under the two optimal preparation processes were almost identical, at 61.87% and 61.18%, respectively. Comparison of the kinetics of TCH degradation under different light conditions (light saturation & non-saturation) for the two optimized m-TiO2@CdS samples, reveals that the optimization model based on photon fluence response exhibits a wider range of light intensity adaptability. The repeatability of m-TiO2@CdS under the best preparation process was examined, and a reasonable mechanism for the photocatalytic degradation of tetracycline by m-TiO2@CdS was elucidated.

Keywords: Photocatalysis, antibiotics, m-TiO2@CdS, Response surface methodology, Photon fluence