Sol-gel synthesis of nanocomposites based on titania-ceria

U radu je opisan postupak priprave Ce-TiO2 fotokatalizatora sa sljedećim udjelima Ce: 0,08%, 0,40%, 0,80%. Za pripravu solova korišteni su: titanijev izopropoksid te cerijev (III) nitrat heksahidrat kao prekursor, 2-propanol kao otapalo, acetilaceton za kompleksiranje, destilirana voda za hidrolizu te nitratna kiselina kao katalizator. Ce-TiO2 sol nanesena je na borosilikatna stakalca postupkom izlijevanja, nakon čega je slijedilo sušenje pri 100 °C, 1 h te toplinska obrada pri 450 °C, brzinom zagrijavanja od 3 °C/min, 2 h. Na dobivenim filmovima provedeno je ispitivanje fotokatalitičke razgradnje antibiotika ciprofloksacina (CIP) tijekom 120 min pri zračenju sličnom Sunčevom. Cilj ovog rada je određivanje utjecaja udaljenosti izvora zračenja od fotokatalizatora na fotokatalitičku aktivnost Ce-TiO2 filmova pri razgradnji antibiotika ciprofloksacina (CIP). Mikroskopijom atomskih sila (AFM) određena je morfologija površine filmova i parametri hrapavosti. Simultanom toplinskom analizom DSC/TG dobiveni su podaci o gubitku mase pri zagrijavanju uzoraka od sobne temperature do 450 °C, ali i podaci o egzotermnim i endotermnim reakcijama u istom rasponu temperatura. Rendgenskom difrakcijom (XRD) određen je fazni sastav te parametri i volumeni jedinične ćelije uzoraka. Fotokatalitičkim ispitivanjima utvrđeno je da smanjenjem udaljenosti umjetnog izvora zračenja od fotokatalizatora dolazi do ubrzanja fotokatalitičke razgradnje ciprofloksacina primjenom Ce-TiO2 filmova. Eksperimentalni rezultati pokazuju da TiO2 fotokatalizator dopiran s 0,80% Ce pokazuje najveću brzinu razgradnje ciprofloksacina primjenom zračenja sličnog Sunčevom.The paper describes the sol-gel process of a Ce-doped TiO2 photocatalyst preparation with the following amount of added Ce: 0.08 wt. %, 0.40 wt. %, 0.80 wt. %. Titanium isopropoxide and cerium (III) nitrate hexahydrate as a precursor, 2-propanol as a solvent, acetylacetone for complexation, distilled water for hydrolysis, and nitric acid as a catalyst were used for the preparation of the sols. The Ce-TiO2 sol was deposited on borosilicate glass samples using a flow coating method. The samples were dried at 100 °C for 1 hrs and heat-treated at 450 °C for 2 hrs at a heating rate of 3 °C/min. The photocatalytic activity of Ce-TiO2 films for 120 min under solar radiation was investigated. The aim of this work is the investigation of the influence of the radiation source distance on the photocatalytic activity of the Ce-TiO2 film for ciprofloxacin (CIP) degradation. Atomic force microscopy (AFM) was used to determine surface morphology and roughness parameters of the films. The weight loss, as well as exothermic and endothermic reactions during the thermal treatment, were obtained by thermal analysis, including thermogravimetric analysis and differential scanning calorimetry (DSC/TG). The phase composition and parameters and volumes of the unit cells were determined by X-ray diffraction (XRD). Photocatalytic studies showed that by decreasing the distance of the radiation source from the samples, the rate of photocatalytic degradation of ciprofloxacin increases. Experimental results show that 0.80 wt. % Ce-TiO2 photocatalyst has the highest speed rate of degradation of ciprofloxacin using solar radiation