A tetraphenylporphyrin/WO3/exfoliated graphite nanocomposite for the photocatalytic degradation of an acid dye under visible light irradiation

Abstract

Visible light photocatalysis has gained attention as a green chemistry protocol for mineralizing organic pollutants. In this contribution, a series of photocatalysts were prepared via a wet-impregnation method using meso-tetraphenylporphyrin (TPP; 0–1 mol%), tungsten(VI) oxide, WO₃ and exfoliated graphite (EG) to degrade Acid Blue 25 (AB-25) dye under visible light irradiation. SEM/EDS, Raman spectroscopy, XRD, FTIR spectroscopy, BET analysis, DR-UV-vis spectroscopy and photoluminescence spectroscopy were used for the characterization of the catalysts. The results confirmed the effects of structural changes, morphological changes and the optical properties of WO₃. Moreover, the visible light-activated photocatalytic performance of WO₃ was improved by EG and TPP and the efficiency of the optimal as-prepared photocatalyst was 99% at pH 5 after 180 minutes of irradiation. The enhanced photocatalytic performance was confirmed by the reduction in the recombination of photogenerated electron–hole pairs. The photocatalyst may be used for the treatment of textile wastewater.