The influence of synthesis conditions on the photocatalytic efficiency of polypyrrole/zinc oxide composites

Cinkov oksid smatra se jednim od najboljih fotokatalizatora s obzirom na njegovu efikasnost i cijenu. Pokazuje veliku učinkovitost na ultraljubičastom (UV) zračenju pa se nastoji modificirati da bi se dobio novi fotokatalitički materijal koji bi apsorbirao cijeli ili barem veći dio Sunčeva zračenja, a ne samo ultraljubičasti dio. Cilj ovog rada bio je dobiti optimalnu količinu vodljivog polimera u kompozitnom materijalu koja će, u kombinaciji sa ZnO, omogućiti učinkovitu razgradnju organskih onečišćenja u vodi kako bi ih preveli u biorazgradljive spojeve ili ih u potpunosti mineralizirali. Provedena je sinteza kompozita polipirol/cinkov oksid (PPy/ZnO), polimerizacijom monomera pirola u prisutnosti ZnO, uz različitu duljinu trajanja reakcije polimerizacije (30, 45, 60 i 75 minuta). Fotokatalitičko djelovanje PPy/ZnO kompozita ispitano je u procesu razgradnje bojila Acid Blue 25 (AB 25). Kompoziti PPy/ZnO okarakterizirani su FTIR spektroskopijom, UV/Vis spektroskopijom i termogravimetrijskom analizom (TGA). Uzorcima je određena i elektrovodljivost. Utvrđeno je da kompoziti uspješno razgrađuju uzorke vode onečišćene bojilom AB 25. Sintetizirani fotokatalitički kompoziti PPy/ZnO imaju prošireno fotokatalitičko djelovanje, pomaknuto prema vidljivom poručju UV/Vis spektra Sunčeva zračenja.Zinc oxide is considered to be one of the best photocatalysts in terms of its efficiency and price. It shows high efficiency under ultraviolet (UV) radiation, but there are many efforts in order to modify ZnO to obtain a new photocatalytic material that would absorb whole or at least most of the sun's radiation, not just the ultraviolet part. The aim of this paper was to obtain the optimum amount of conductive polymer in composite material that will, in combination with ZnO, enable efficient decomposition of organic pollutants in water to transform them into biodegradable compounds or fully mineralize them. The synthesis of the composite polypyrrole/zinc oxide (PPy/ZnO) has been carried out by polymerization of pyrrole monomer in the presence of ZnO, with various duration of polymerization (30, 45, 60 and 75 minutes). The photocatalytic activity of PPy/ZnO composites was tested in the process of degradation of the dye Acid Blue 25 (AB 25). PPy/ZnO composites are characterized by FTIR spectroscopy, UV/Vis spectroscopy and thermogravimetric analysis (TGA). Electrical conductivity was also determined. It has been determined that PPy/ZnO composites successfully decompose pollution caused by AB 25. Synthesized PPy/ZnO composites have enhanced photocatalytic activity in the visible region of solar radiation