Eliminating the need for organic hole scavenger in the photoreduction of selenite and selenate from aqueous phase

Effect of Calcination Temperature on the Morphology, Crystallinity, and Photocatalytic Activity of ZnO/TiO2 in Selenite Photoreduction from Aqueous Phase

“…As the calcination increased to 500 C, the peaks became weaker and broader, which implies that a certain amount of the O-H groups were removed from the surfaces of the catalysts due to the calcination [37]. The peaks that appear in the range of 415 cm -1 -630 cm -1 are significant peaks that confirm the ZnO/TiO2 nanocomposite [28]. The peak range of 400 cm -1 -550 cm -1 is attributed to the Zn-O stretching mode [30,38,39].…”

“…ZnO/TiO2 nanocatalyst was synthesized by the sol-gel method according to the procedure outlined by Usman et al [28]. ZnO/TiO2 was synthesized from commercial TiO2 powder, and zinc acetate dehydrate.…”

“…Figures 2 show the SEM of the ZnO/TiO2 synthesized and calcined at different temperatures. Figure 2 A [28] is the control which is the SEM image of the uncalcined nanocomposite. The morphology of the uncalcined sample consists of agglomerated granular particles.…”

“…In Figure 4., various functional groups found in the nanocatalyst samples were analyzed using FTIR spectroscopy. The broad peaks at 3421 cm -1 wavelength are attributed to the O-H stretching vibrations due to moisture on the nanocatalysts' surfaces [28,30,36,37]. As the calcination increased to 500 C, the peaks became weaker and broader, which implies that a certain amount of the O-H groups were removed from the surfaces of the catalysts due to the calcination [37].…”

“…This necessitates using organic hole scavengers, which are usually left partially untreated and can cause oxygen depletion in the receiving water bodies. A previous study by Usman et al [28] synthesized ZnO/TiO 2 and applied it successfully for the photoreduction of selenium species without using organic hole scavengers.…”