Photodeposition of Pd nanoparticles on TiO 2 utilizing a channel type quartz reactor

Abstract

Abstract In this research a channel type quartz reactor with inner diameter of 2.8 mm was utilized for photodeposition of palladium nanoparticles on titania. High surface to the volume ratio of the reactor and a flash irradiation time of 0.5 s per once passing of solution through the reactor are the benefits of utilizing this type of reactor. Samples of Pd@TiO 2 with Pd loadings of 0.35, 1.3 and 1.54 wt% were prepared. AAS, IR spectra, XRD, UV–Vis spectroscopy and HR-TEM were utilized for characterization of the samples. Furthermore, the photocatalytic activities of the samples were evaluated by degradation of methylene blue under visible light irradiation. Band-gap reduction from 3.25 to 3 eV as well as enhancement of degradation rate constant from 0.008 to 0.023 1/min for bare and Pd loaded titania respectively, were the main results of this exploration. Data from photodegredation test endorses the notion that higher catalytic activity is achieved by smaller Pd particles with mono size distribution. The sample with mono-dispersed Pd particles all smaller than 8 nm is more photocatalytically active than the sample with higher loading amount but broad Pd particle distribution from 2.5 to 15 nm.