Enhanced photocatalytic degradation of tetracycline using α-Fe2O3@TiO2- impregnated Mxene photocatalyst: Mechanism and optimization of process via RSM and ANN

Abstract

This study involves the synthesis, characterization, and optimization of a remarkably effective α-Fe2O3@TiO2@MXene ternary photocatalyst, which was synthesized by employing an expeditious and controllable ultrasonic-assisted technique. The tetracycline (TC) photocatalytic decomposition was investigated under visible-light, an effective and eco-friendly approach. Impact of different factors on the synthesis process, including α-Fe2O3@TiO2 content (2−32 wt%) and calcination temperature (300–600°C), were examined via Response Surface Methodology- Central Composite Design (RSM-CCD) for the first time. Based on degradation test results, the optimum conditions were determined to be 18.91 % and 441°C, respectively. Additionally, the operational parameters for TC degradation were explored within dosage of catalyst (0.2−1.5 g.L−1), tetracycline concentration (5−65 ppm), irradiation time (20−160 min), and pH (2−10) by RSM and Artificial Neural Network (ANN) methods. Optimal operating conditions for aforementioned variables were found to be 0.54 g.L−1, 39.37 ppm, 124 min, and pH of 4.83, respectively, with degradation efficiency of 98.36 % and 96.22 % according to RSM-CCD and ANN analysis. Considering the trapping test, •O2- and •OH- radicals are the primary species responsible for the degradation of TC. The PL analysis indicated that the rate of photogenerated recombination diminished following the impregnation of Fe2O3/TiO2 particles onto the MXene. Furthermore, the experimental evidence demonstrated that the Fe2O3@TiO2@MXene heterojunction photocatalyst effectively decomposed TC with 84.65 % Chemical oxygen demand (COD) removal. The stability of the Fe2O3@TiO2@MXene catalyst was exceptional throughout the photocatalysis process with negligible leaching of Fe2O3@TiO2 over four cycles.