Iodic acid

The chemicals used in this study are as follows: Tungsten oxide (WO₃, nanopowder, Sigma-Aldrich), titanium dioxide (TiO₂, P25, nanopowder, Evonik), bismuth vanadate (BiVO₄, nanopowder, Alfa Aesar), PA (HIO₄·2H₂O, ≥99.0%, Sigma-Aldrich), iodic acid (HIO₃, ≥99.5%, Sigma-Aldrich), sodium periodate (NaIO₄, ≥99.8%, Sigma-Aldrich), sodium iodate (NaIO₃, 99%, Sigma-Aldrich), sodium iodide (NaI, ≥99.0%, Sigma-Aldrich), chloroplatinic acid (H₂PtCl₆·xH₂O, ≥99.9%, Sigma-Aldrich), MeOH (CH₃OH, 99.9%, Samchun Chemicals), IPA ((CH₃)₂CHOH, 99.5%, Sigma-Aldrich), AT (CH₃COCH₃, 99.98%, Burdick Jackson), DCM (CH₂Cl₂, ≥99.8%, Sigma-Aldrich), C5 (CH₃(CH₂)₃CH₃, ≥99.0, Sigma-Aldrich), ClC₃ (CH₃CH₂CH₂Cl, 99%, Alfa Aesar), 5,5-dimethyl-1-pyrroline-N-oxide (DMPO, ≥ 98.0, Sigma-Aldrich). Tol (300 ppmv, N₂ balance), AA (1000 ppmv, N₂ balance), FA (100 ppmv, N₂ balance), high-purity synthetic air (79% N₂/21% O₂) were purchased from Deokyang Company. All chemicals were of reagent grade and used as received without further purification. Ultrapure deionized water (18 MΩ cm) prepared using a Millipore system was used.

Figure 3 shows the molecular structure of the 27 ILs used in this study (Figure 3 and Table S3). [C₂–C₆mim][Cl] and [C₄mim][MeSO₄, DCA, SCN and TCM] were provided by Merck KGaA (Darmstadt, Germany). [TMC₈A][Cl], [DODMA][Cl], [C₁mim][Cl], [C₄mim][I and TCA] were synthesized using the CBILS^® (is a registered trademark of Proionic GmbH) route [60 ,61 (link)] as previously described by Fister et al. [62 (link)]. The precusor ILs used for synthesis of ([TMC₈A] and [C₄mim][MC]) were provided by Proionic GmbH (Grambach, Austria). Hydrochloric acid and trichloroacetic acid were obtained from Merck KGaA (Darmstadt, Germany), iodic acid was purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany). [C₁₂–C₁₆mim][Cl] and [C₁₀C₁₀im][Cl] were purchased from Iolitec (Ionic Liquid Technologies, Heilbronn, Germany). All other ILs were provided by Proionic GmbH (Grambach, Austria). IL-solutions were prepared at concentration of 100,000 mg/L, 50,000 mg/L, 20,000 mg/L and 2000 mg/L, 200 mg/L, 20 mg/L and 2 mg/L (w/v in water).

Titania organic precursor: titanium(IV) butoxide (99+%) was provided by Alfa Aesar (Haverhill, MA, USA). Iodic acid (99.5%), nitric acid (68%), and hydrogen peroxide (30%) were purchased from Sigma (Poznan, Poland) and were used for TiO₂ structure modification. Acetonitrile and orthophosphoric acid (85%) for HPLC mobile phase preparation were provided by Merck (Darmstadt, Germany) and VWR (Gdansk, Poland), respectively. Phenol, used as a model organic recalcitrant pollutant in photocatalytic activity measurements, was purchased from VWR. All reagents were used without further purification.