Immobilized TiO 2 was prepared by adding a small composition of polyethylene glycol (PEG) as a binder, and this paper reported for the very first time the formation of C=O from oxidized PEG, which acted as an electron injector in enhancing photoactivity. Water-based TiO 2 with PEG formulation was deposited by using a brush technique onto double-sided adhesive tape (DSAT) as a support binder to increase the adhesiveness of immobilized TiO 2 . The photocatalytic activity of immobilized TiO 2 -PEG was measured by photodegradation of 12 mg·L −1 methylene blue (MB) dye. The optimum condition of immobilized TiO 2 -PEG was observed at TiO 2 /PEG-2 (TP2) with 10:0.1 for the TiO 2 /PEG ratio, which resulted in a 1.8-times higher photodegradation rate as compared to the suspension mode of pristine TiO 2 . The high photodegradation rate was due to the formation of the active C=O bond from oxidized PEG binder in immobilized TiO 2 -PEG as observed by Fourier transform infrared and X-ray photoelectron spectroscopy analyses. The presence of C=O has escalated the photoactivity by forming an electron injector to a conduction band of TiO 2 as proven by higher photoluminescence intensity obtained for TP2 as compared to pristine TiO 2 . The TP2 sample has also increased its adhesiveness when DSAT is applied as a support binder where it can be recycled up to eight times and comparable to recent photocatalysis cycle developments.

Abstract:Immobilized TiO 2 and immobilized TiO 2 -polyethylene glycol (TiO 2 /PEG) films have been prepared via brush coating method. The formulation of immobilized TiO 2 film was prepared by mixing distilled water with P25, while the formulation containing P25 combined with 8% PEG in distilled water was used in preparing immobilized TiO 2 /PEG. A double sided adhesive tape (DSAT) was stacked onto a glass surface prior to coating with the formulations and annealing by a thermal treatment at 100 • C for 15 min. The photocatalytic activity of immobilized photocatalysts was evaluated under photodegradation of methylene blue (MB). It was observed that immobilized TiO 2 /PEG has showed a higher rate of photocatalytic activity compared to immobilize TiO 2 . The X-ray photoelectron spectroscopy and Fourier transform infrared (FT-IR) spectra of immobilized TiO 2 /PEG sample proved that the existence of C=O led to enhanced photoactivity efficiency under normal light and visible light irradiations. The photocatalytic activity performance of immobilized TiO 2 /PEG was the highest at 75 mL·min −1 aeration rate and pH 11 of MB dye. The correlation between of all these parameters was investigated in this study.

A new immobilized TiO2technique was prepared by coating TiO2solution onto double-sided adhesive tape (DSAT) as a thin layer binder without adding any organic additives. Glass plate was used as support material to immobilized TiO2/DSAT. Two different charges of dyes were applied, namely, anionic reactive red 4 (RR4) and cationic methylene blue (MB) dyes. Photocatalytic degradation of RR4 and MB dyes was observed under immobilized TiO2/DSAT with the degradation rate slightly lower and higher, respectively, compared with TiO2in suspension mode. It was observed that DSAT is able to provide a very strong intact between glass and TiO2layers thus making the reusability of immobilized TiO2/DSAT be up to 30 cycles. In fact, a better photodegradation activity was observed by number of cycles due to increasing formation of pores on TiO2surface observed by SEM analysis.

Abstract. Novel photocatalysts of TiO2 and TiO2/PEG were immobilized using new technique which is double sided adhesive tape (DSAT) as a thin layer binder onto glass plate. The photocatalytic activity study of immobilized/TiO2 and immobilized/TiO2/PEG were carried out by irradiating of 36 mg L -1 MB dye in the presence of normal and visible light with rate of decolourization was estimated from aliquot concentration spectrophotometrically. The high photocatalytic activity from immobilized/TiO2/PEG was observed with the rate constants of ca 0.06 and 0.02 min -1 under normal and visible light irradiation respectively. An active photocatalytic activity was observed for immobilized/TiO2/PEG sample while no photocatalytic activity detected under immobilized/TiO2. The high photoactivity was also detected under normal light for immobilized/TiO2/PEG sample. This might be due to the presence of electron conjugate in PEG that acted as electron donor for TiO2 thus increase the photocatalysis process. Moreover, this electron donor is reported to be able to become active under low energy visible light hence the immobilized/TiO2/PEG can perfomed its photoactivity under visible light irradiation.