title: Efficiency enhancement of dye-sensitized solar cells by use of ZrO2-doped TiO2 nanofibers photoanode.
abstract: Due to the good stability and convenient optical properties, TiO2 nanostructures still the prominent photoanode materials in the Dye Sensitized Solar Cells (DSCs). However, the well-known low bandgap energy and weak adsorption affinity for the dye distinctly constrain the wide application. This work discusses the impact of Zr-doping and nanofibrous morphology on the performance and physicochemical properties of TiO2. Zr-doped TiO2 nanofibers (NFs), with various zirconia content (0, 0.5, 1, 1.5 and 2wt%) were prepared by calcination of electrospun mats composed of polyvinyl acetate, titanium isopropoxyl and zirconium n-propoxyl. For all formulations, the results have shown that the prepared materials are continuous, randomly oriented, and good morphology nanofibers. The average diameter decreased from 353.85nm to 210.78nm after calcination without a considerable influence on the nanofibrous structure regardless the zirconia content. XRD result shows that there is no Rutile nor Brookite phases in the obtained material and the average crystallite size of the sample is affected by the presence of Zr-doping and changed from 23.01nm to 37.63nm for TiO2 and Zr-doped TiO2, respectively. Optical studies have shown Zr-doped TiO2 NFs have more absorbance in the visible region than that of pristine TiO2 NFs; the maximum absorbance is corresponding to the NFs having 1wt% zirconia. The improved spectra of Zr-doped TiO2 in the visible region is attributed to the heterostructure composition resulting from Zr-doping. The absorption bandgaps were calculated using Tauc model as 3.202 and 3.217 for pristine and Zr (1wt%)-doped TiO2 NFs, respectively. Furthermore, in Dye-sensitized Solar Cells, utilizing Zr (1wt%)-doped TiO2 nanofibers achieved higher efficiency of 4.51% compared to the 1.61% obtained from the pristine TiO2 NFs.
authors.affiliation: Bionanosystem Engineering Department, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Ibrahim M A
authors.initials: IMA
authors.lastname: Mohamed
authors.affiliation: Department of Chemical Engineering, Chungnam National University, 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
authors.forename: Van-Duong
authors.initials: VD
authors.lastname: Dao
authors.affiliation: Bionanosystem Engineering Department, Chonbuk National University, Jeonju 561-756, Republic of Korea; Chemical Engineering Department, Faculty of Engineering, Minia University, El-Minia, Egypt. Electronic address: nasser@jbnu.ac.kr.
authors.forename: Nasser A M
authors.initials: NAM
authors.lastname: Barakat
authors.affiliation: Bionanosystem Engineering Department, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: Yasin
authors.affiliation: Bionanosystem Engineering Department, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Yousef
authors.affiliation: Department of Chemical Engineering, Chungnam National University, 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
authors.forename: Ho-Suk
authors.initials: HS
authors.lastname: Choi
keywords: Dye-sensitized solar cell; Nanofibers; Photoanode electrode; Solar energy; Zr doping