File Name : figure s1.tif Caption : figure s1: schematic (a) photocatalytic (pc) and photo-fenton (pf) process setup and (b) sampling methodologies for evaluating the degradation of ps mps after the pc and pf processes. File Name : figure s2.tif Caption : figure s2: (a) xrd pattern of two-step annealed tiap and bet adsorption-desorption isotherm of tiap, all concentrations of fe-modified tiap, and two-step annealed tiap, respectively. File Name : figure s3.tif Caption : figure s3: photocatalytic (pc) and photo-fenton (pf) processes-based degradation extent of caffeine using tiap and fe-modified tiap (photocatalyst: 0.2 mg/ml, volume: 30 ml, caffeine: 20 ppm, ph 3 and pf process: ph 3, 0.1 mm h2o2, irradiation time: 2 h). File Name : figure s4.tif Caption : figure s4: (a) changes in atr-ir spectra before (0 min) and after (480 min) the photocatalytic (pc) process for the tiap and different concentrations of iron-modified tiap. on the right side, zoomed-in spectra of the peroxyl group (b), carbonyl group (c), and reference group (d), respectively. File Name : figure s5.tif Caption : figure s5: (a) changes in atr-ir spectra before (0 min) and after (480 min) the photo-fenton (pf) process for the tiap and different concentrations of iron-modified tiap. on the right side, zoomed-in spectra of the peroxyl group (b), carbonyl group (c), and reference group (d), respectively. File Name : figure s6.tif Caption : figure s6: relative changes in the ci and pi value after the photo-fenton (pf)-based process for tiap0.1fe and homogenous pf process using fe2+ at different ph ranges. File Name : figure s7.tif Caption : figure s7: (a) 1h nmr spectra of non-modified tiap after 480 min and 24 h of photocatalytic (pc) process. solvent peaks are marked with an asterisk (*). (b) toc taken after 24 h of pc degradation of ps mps using non-modified tiap. File Name : figure s8.tif Caption : figure s8: representative hr-sem images of samples with a lower change in ci value after photo-induced treatment processes File Name : figure s9.tif Caption : figure s9: tga/dsc-ms curves of non-modified tiap before (a) and after (b) the addition of h2o2 for the degradation of ps mps. File Name : figure s10.tif Caption : figure s10: tga/dta-ms curves of tiap0.1fe before (a) and after the photocatalytic (pc) (b) and photo-fenton (pf)-based (c) degradation of ps mps. File Name : figure s11.tif Caption : figure s11: tga/dsc-ms curves of tiap0.01fe before (a) and after (b) the photo-fenton (pf)-based degradation of ps mps. File Name : figure s12.tif Caption : figure s12: (a) zeta potential measurements of tiap, tiap0.1fe, caffeine, and ps mps at near neutral ph and acidic ph (~3), respectively. (b) methylene blue (mb) degradation using tiap0.1fe after the photocatalytic (pc) and photo-fenton (pf) process (photocatalyst: 0.2 mg/ml, reaction volume: 30 ml, mb: 20 ppm, ph 3 and pf process: ph 3, 0.1 mm h2o2, irradiation time: 2 h). File Name : figure s13.tif Caption : figure s13: (a) 1h nmr spectra of homogenous photo-fenton (pf) process using fe2+ salts and (b) the zoomed-in spectra between 0.8-1.3 ppm. solvent peaks are marked with an asterisk (*). File Name : figure s14.tif Caption : figure s14: hplc chromatogram of blank vs ps mps and tiap_with h2o2 at the wavelength of 220 nm. File Name : figure s15.tif Caption : figure s15: hplc chromatogram of blank vs ps mps and tiap_with h2o2 at the wavelength of 280 nm. File Name : figure s16.tif Caption : figure s16: based on the hplc-hrms data, possible intermediates formed during polystyrene degradation were identified. structures were predicted through https://www.chemspider.com/search. marvin was used to draw the chemical structures of ps and their intermediates, marvin 17.21.0, chemaxon (https://www.chemaxon.com). File Name : figure s17.tif Caption : figure s17: (a) relative changes in the ci and pi and (b) 1h nmr spectra after the photocatalytic (pc) and photo-fenton (pf)-based process for tiap0.1fe with the addition of isopropyl alcohol (500 mm) and p-benzoquinone (5 mm) as a scavenger. (c) the zoomed-in 1h nmr spectra between 0.8-1.3 ppm. solvent peaks are marked with an asterisk (*). File Name : figure s18.tif Caption : figure s18: mechanism of photo-fenton process in degrading ps mps using tiap0.1fe.