title: Effect of solvents on the extraction of natural pigments and adsorption onto TiO2 for dye-sensitized solar cell applications.
abstract: Nine solvents, namely, n-hexane, ethanol, acetonitrile, chloroform, ethyl-ether, ethyl-acetate, petroleum ether, n-butyl alcohol, and methanol were used to extract natural dyes from Cordyline fruticosa, Pandannus amaryllifolius and Hylocereus polyrhizus. To improve the adsorption of dyes onto the TiO2 particles, betalain and chlorophyll dyes were mixed with methanol or ethanol and water at various ratios. The adsorption of the dyes mixed with titanium dioxide (TiO2) was also observed. The highest adsorption of the C.fruticosa dye mixed with TiO2 was achieved at ratio 3:1 of methanol: water. The highest adsorption of P.amaryllifolius dye mixed with TiO2 was observed at 2:1 of ethanol: water. H.polyrhizus dye extracted by water and mixed with TiO2 demonstrated the highest adsorption among the solvents. All extracted dye was adsorbed onto the surface of TiO2 based on Fourier Transform Infrared Spectroscopy (FTIR) analysis. The inhibition of crystallinity of TiO2 was likewise investigated by X-ray analysis. The morphological properties and composition of dyes were analyzed via SEM and EDX.
authors.affiliation: Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia; Department of Biology, College of Education for Pure Sciences/Ibn Al-Haitham, University of Baghdad, Baghdad, Iraq. Electronic address: mamash73@yahoo.com.
authors.forename: Mahmoud A M
authors.initials: MA
authors.lastname: Al-Alwani
authors.affiliation: Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia.
authors.forename: Abu Bakar
authors.initials: AB
authors.lastname: Mohamad
authors.affiliation: Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia.
authors.forename: Abd Amir H
authors.initials: AA
authors.lastname: Kadhum
authors.affiliation: Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia.
authors.forename: Norasikin A
authors.initials: NA
authors.lastname: Ludin
mesh_terms: D000327:Adsorption; D050859:Betacyanins / Q000302:isolation & purification; D029421:Cactaceae / Q000737:chemistry*; D002734:Chlorophyll / Q000302:isolation & purification; D031406:Cordyline / Q000737:chemistry*; D011211:Electric Power Supplies; D031673:Pandanaceae / Q000737:chemistry*; D010848:Picolinic Acids / Q000302:isolation & purification; D010860:Pigments, Biological / Q000302:isolation & purification*; D012993:Solar Energy; D012997:Solvents / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D050859:Betacyanins; D010848:Picolinic Acids; D010860:Pigments, Biological; D012997:Solvents; C488995:betaxanthin; D002734:Chlorophyll; C009495:titanium dioxide; C020228:betanin; D014025:Titanium
keywords: Betanin; Betaxanthins; Chlorophyll; Dye-sensitized solar cell; Natural pigments; Solvents