Micro-sized TiO2 catalyst in powder form and as coating on porcelain grès tile for the photodegradation of phenol as model pollutant for water phase

Abstract

In presence of TiO2 and irradiation, phenol can be degraded by hydroxyl radicals or directly via photogenerated carriers, as occurs in photocalytic processes. In this work a commercial micro-sized TiO2 sample in powder form and industrially coated on porcelain grès tiles were tested in water remediation with phenol as model molecule. Firstly, we investigated the behaviour of the commercial micro-sized TiO2 comparing the results with reference nano-sized catalyst in the phenol photodegradation process, widely studied in the last decades. Following the phenol concentration as well as the main intermediates formation over time by HPLC analysis, and the mineralization by TOC analysis, we presented results about the photocatalytic behaviour in terms of adsorption, by-products formation, and reaction rate at different phenol starting concentrations. In particular, with the photocatalytic tiles, phenol photodegradation percentage is almost the same at 15 ad 25 ppm (78% and 73% respectively), and much lower at 50 ppm (46%) after 6 hours of test. Correspondence to: Claudia L. Bianchi, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy, E-mail: claudia. bianchi@unimi.it Benedetta Sacchi, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy, E-mail: benedetta.sacchi@unimi.it Giuseppina Cerrato, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy, E-mail: giuseppina.cerrato@unito.it