Synthesis of TiO2–Ag3PO4 photocatalyst material with high adsorption capacity and photocatalytic activity: application in the removal of dyes and pesticides

Abstract

The photocatalytic activity of TiO₂ can be enhanced by coupling it with other semiconductors and the semiconductor composites may find useful application in water treatment technologies. TiO₂–Ag₃PO₄ composites were synthesized and characterized with XRD, SEM-EDX and DRS. The synthesized TiO₂–Ag₃PO₄ showed high photocatalytic activity in the presence UV-vis light on rhodamine B, methylene blue and the pesticides imidacloprid, atrazine and pyrimethanil. LC-MS analysis of the photodegraded pyrimethanil led to the identification of hydroxylated and aliphatic derivatives of pyrimethanil. The photocatalytic activity of the coupled semiconductor was higher than that of the bare TiO₂ and Ag₃PO₄ and this was attributed to the unique band matching between TiO₂ and Ag₃PO₄ which resulted in efficient charge separation and subsequent reduction in the electron–hole recombination. In addition, the synthesized TiO₂–Ag₃PO₄ showed strong adsorption for water soluble dyes implying that TiO₂–Ag₃PO₄ can remove pollutants through photocatalysis and adsorption. The results from the study showed the potential application of TiO₂–Ag₃PO₄ composite in water treatment technologies.