Photocatalytic degradation of 2-(4-methylphenoxy)ethanol over TiO2 spheres

Abstract

The photocatalytic TiO2-assisted decomposition of 2-(4-methylphenoxy)ethanol (MPET) in aqueous solu-tion has been studied for the first time. The intermediate compounds of MPET photodegradation havebeen also determined. A toxic p-cresol is formed in significant quantities during the photocatalytic reac-tion. A solvent-exchange approach for a template-free preparation of spherical TiO2particles has beendescribed, which is based solely on precipitation of hydrous titania from aqueous titanium peroxo com-plex by using organic solvents. The proposed method favours the formation of spherical titania particleswith a mean size varying from 50 to 260 nm depending on the choice of solvent. The procedure for con-verting nonporous titania spheres into mesoporous material maintaining the same spherical morphologyhas been developed. The synthesized TiO2spheres demonstrate a degree of MPET photo-degradationclose to that of the commercial titania Aeroxide P25, besides being successfully recovered and reused forfour reaction cycles without loss of photocatalytic activity. The effectiveness of the commercial AeroxideP25 in MPET photodegradation, on the other hand, suffers 10-time drop during the third reaction cycle,which is attributed to its poor recoverability because the photocatalyst is composed of small particles of20 nm size.