Synthesis and photocatalytic activity of polyoxometalates immobilized onto g-C3N4/ZIF-67 heterostructures

Herein, ternary organic/inorganic semiconductor heterostructures of phosphotungstic acid (PTA) immobilized on g-C3N4/ZIF-67 has been synthesized, and studied using XRD, FE-SEM, EDX, TEM, PL, FTIR, Zeta potential UV–visible DRS, and N2 adsorption-desorption analysis. The photocatalytic degradation of methyl violet dye (MV) in aqueous solutions was studied using constructed visible-light-driven g-C3N4/ZIF-67/PTA composites. The g-C3N4/ZIF-67/PTA sample has outstanding degradation activity (98%) while its constituents presented less photocatalytic activity within 90 min. Furthermore, several factors, including initial pH of the MV solution, the concentration of MV dye, and the dose of the g-C3N4/ZIF-67/PTA photocatalyst have been studied in detail in this work. The boosted photocatalytic performance was owing to the synergistic influence between PTA, ZIF-67, and g-C3N4 and, which was clarified by the mechanism of fast charge transfer and separation. Additionally, g-C3N4/ZIF-67/PTA exhibited good photocatalytic stability for five consecutive cycles and therefore it expected to be very useful in contaminated water treatment.