%T An investigation of the stirring duration effect on synthesized graphene oxide for dye-sensitized solar cells
%V 15
%I Public Library of Science
%A X.H. Yau
%A F.W. Low
%A C.S. Khe
%A C.W. Lai
%A S. Tiong
%A N. Amin
%X This study investigates the effects of stirring duration on the synthesis of graphene oxide (GO) using an improved Hummers� method. Various samples are examined under different stirring durations (20, 40, 60, 72, and 80 h). The synthesized GO samples are evaluated through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The GO sample with 72 h stirring duration (GO72) has the highest d-spacing in the XRD results, highest atomic percentage of oxygen in EDX (49.57), highest intensity of oxygen functional group in FTIR spectra, and highest intensity ratio in Raman analysis (ID/IG = 0.756). Results show that GO72 with continuous stirring has the highest degree of oxidation among other samples. Electrochemical impedance spectroscopy analysis shows that GO72�titanium dioxide (TiO2) exhibits smaller charge transfer resistance and higher electron lifetime compared with the TiO2-based photoanode. The GO72 sample incorporating TiO2 nanocomposites achieves 6.25 photoconversion efficiency, indicating an increase of more than twice than that of the mesoporous TiO2 sample. This condition is fully attributed to the efficient absorption rate of nanocomposites and the reduction of the recombination rate of TiO2 by GO in dye-sensitized solar cells. © 2020 Yau et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
%K graphene oxide; nanocomposite; oxygen; titanium dioxide nanoparticle; coloring agent; graphene oxide; graphite, absorption parameters; Article; electron transport; energy dispersive X ray spectroscopy; field emission scanning electron microscopy; Fourier transform infrared spectroscopy; Hummer method; impedance spectroscopy; oxidation; Raman spectrometry; reduction (chemistry); synthesis; time; X ray diffraction; chemistry; power supply; solar energy, Coloring Agents; Electric Power Supplies; Graphite; Solar Energy
%D 2020
%R 10.1371/journal.pone.0228322
%N 2
%O cited By 6
%L scholars13499
%J PLoS ONE