Synthesis of Ag 3 PO 4 -polyvinyl alcohol hybrid microcrystal with enhanced visible light photocatalytic activity

Synthesis of Ag3PO4 using Hydrophylic Polymer and Their Photocatalytic Activities under Visible Light Irradiation

“…Figure 4 shows the photocatalytic activities of Ag3PO4 synthesized without and with hydrophylic polymer of PVA, PEG and PVP. The rate constants are evaluated by the following apparent pseudo-first-order kinetics equation [10,12,13] as depicted in Equation (2). (2) where C0 and C are the concentrations of dye in solution at times 0 and t, respectively, and kapp is the apparent pseudo-first-order rate constant (min −1 ).…”

“…The Ag3PO4 synthesized using PEG showed the absorption band edge shift to the lower wavelength (blue shift). The band gaps of the samples were calculated from the DRS using the equation of direct transition semiconductor [10,12] as presented in Equation (1): (1) where α, ν, Eg, and A are absorption coefficient, light frequency, band gap energy, and a constant, respectively. The band gap of 2.35, 2.32, 2.37, and 2.35 eV could be observed in Ag3PO4, Ag3PO4/PVA, Ag3PO4/PEG, and Ag3PO4/PVP, respectively (Table 1).…”

“…To evaluate the photocatalytic activity, after mixing the 100 ml of Rhodamine B solution (10 mg/L) and 100 mg of catalyst by stirring at room temperature for 20 minutes (under dark condition), the LED blue light (λ = 445 nm) was irradiated, and the solution was withdrawn every 10 minutes, centrifuged at 14,000 rpm to separate the catalyst, then the concentrations of RhB were measured using a spectrophotometer [10,11].…”

“…The precipitates were separated by 14,000 rpm centrifugation. The samples were washed with water and acetone, dried in a vacuum over night at 60 o C [10].…”

“…With this method, the cubic Ag3PO4 particles was found and showed high photocatalytic activity due to the larger surface area and easier separation of hole-electron pairs. The hydrophylic polymer of polyvinyl alcohol (PVA) could also be used to synthesize the Ag3PO4/PVA microcrystal hybrid film using a co-precipitation method [10]. The Ag3PO4/PVA hybrid showed excellent photocatalytic degradation of RhB under visible light irradiation.…”