Photocatalytic degradation of phenol under visible light using electrospun Ag/TiO2 as a 2D nano-powder: Optimizing calcination temperature and promoter content

Abstract

• Electrospun Ag/TiO 2 nanofiber (2D nano powder) was tested for phenol degradation. • Calcination temperature of 450℃ is the best one with a Rutile fraction of 23.8%. • An optimum value of thr Ag promoter is 5% in these photocatalytic experiments. • Adding 5% Ag to the TiO 2 nanofiber decrease the band gap from 3.27 to 3.03 nm. • Nanofibers as 2D nano-powder can be separated easily because of micrometric length. Phenol is one of the toxic materials, and releasing it into the water can be quite irritating and harmful to the health of organisms and the environment. In this study, phenol degradation was investigated using Ag/TiO 2 electrospun nanofiber photocatalyst as a 2D nano-powder. Nanofibers have 2 dimensions in the range of nanometers but their length of them are in the range of micrometers. The micrometer size is an advantage for the separation of the photocatalyst from the suspension. Though, nanometer size is suitable for increasing the available surface for the light. The effect of silver content (0.5–15%) as a promoter and the calcination temperature (300–900 °C) was studied on the degradation of phenol over the synthesized nanofiber-based photocatalyst. Photocatalysts were characterized by various techniques including N 2 -physisorption, XRD, SEM, EDX, TEM, FTIR, TGA/DSC, TPO, and DRS. The results have indicated that 5% of Ag content on TiO 2 is the best promoter loading in these experiments. Furthermore, the calcination temperature of 450 °C is found to be the optimum value with an optimum rutile fraction of 23.8%. Maximum phenol degradation was 82.65% at pH = 7, catalyst dosage of 1.5 g/L, and phenol concentration of 5 ppm under a low power visible light (18 W).