TiO2/PANI nanocomposites for photocatalytic application

Abstract

Poznato je da je titan-dioksid, kao netoksičan, stabilan i ekonomičan materijal, jedan od najčešće korišćenih fotokatalizatora. S druge strane, elektroprovodni polianilin (PANI) je takođe pogodan kandidat za primenu u fotokatalizi. Cilj ovog rada bio je dobijanje nanokompozita TiO2/PANI sa boljom fotokatalitičkom aktivnošću u odnosu na TiO2. U cilju optimizacije sadržaja polimera sintetisano je 4 uzorka TiO2/x%PANI (x = 0, 1, 3 i 5 mas.%), koji su okarakterisani XRD i TG/DTA metodama, dok je fotokatalitička aktivnost ispitana kroz razgradnju toksične tekstilne boje RO16. Pokazano je da su svi kompoziti fotokatalitički aktivniji od TiO2, i da optimalan sadržaj polianilina iznosi 3 mas.%. Naime, uzorak TiO2/3%PANI je, nakon 60 minuta, razgradio 95 % boje, što je za 17 % više u odnosu na TiO2, dok je nakon 120 minuta fotorazgradnja boje potpuna. Pored toga, ovaj uzorak je pokazao čak 14 puta izraženiju adsorpciju od TiO2. Efikasnost TiO2/5%PANI je slična TiO2/3%PANI, ali sa slabije izraženim adsorpcionim svojstvima, dok je efikasnost TiO2/1%PANI bliska TiO2.

It is well known that the non-toxic, stable and economical titanium dioxide is one of the most commonly used photocatalysts. On the other hand, the conductive polyaniline (PANI) is also suitable candidate for photocatalytic application. The aim of this work was to obtain the TiO2/PANI nanocomposites with increased photocatalytic activity comparing to TiO2. In order to determine the optimal PANI content, four TiO2/x%PANI samples (x = 0, 1, 3 and 5 wt.%) were synthesized and characterized by XRD and TG/DTA analysis. The photocatalytic activity was tested on the toxic textile RO16 dye. It is shown that all the composites exhibited better photocatalytic performances than TiO2 and that the optimal PANI content amounted 3 wt.%. Namely, the TiO2/3%PANI degraded 95 % of the dye within 60 minutes, which is for 17 % better comparing to TiO2. The full photodegradation was reached in 120 min. This sample showed even 14 times better adsorption than TiO2. The efficiency of TiO2/5%PANI was similar to TiO2/3%PANI, but with poorer adsorption, while the efficiency of TiO2/1%PANI was close to TiO2.