Fabrication of Ag3PO4/TiO2@molecular sieve (MS) ternary composites with remarkably enhanced visible light-responded photocatalytic activity and mechanism insight

Abstract

In this study, Ag₃PO₄/TiO₂@molecular sieve (MS) ternary composites were fabricated via in-situ deposition and hydrothermal growth method for photocatalytic degradation of formaldehyde and sodium isobutyl xanthate (SIBX) under visible light irradiation. XRD, PL, UV-vis, UPS, SEM-EDS and XPS techniques were adopted to characterize the composite. The results show that the MS material was indexed as zeolite P and Ag₃PO₄-TiO₂ hybrid structure could improve the absorption of visible light and greatly inhibit the recombination of photogenerated charge carriers by introducing 3 times TiO₂. After evaluating the photocatalytic activity and kinetics model, it is found that photocatalytic activity is consistent with the apparent first-order kinetic model. The Ag₃PO₄/TiO₂-3@MS ternary composite under visible light irradiation appears the highest removal rate with 97.9% of formaldehyde and 96.7% of SIBX, respectively. Furthermore, the reusability of the photocatalyst was investigated by successive reuse. After five reuses, the removal rates reached 97.3% and 94.6% within 105 min for formaldehyde and SIBX, respectively. At last, the proposed mechanism of the photocatalytic reaction and the degradation routes of formaldehyde and SIBX were systematically discussed.

Keywords: Ag(3)PO(4)–TiO(2); Formaldehyde; Molecular sieve; Photocatalysis; Sodium isobutyl xanthate.