An investigation of the stirring duration effect on synthesized graphene oxide for dye-sensitized solar cells

Xin Hui Yau; Foo Wah Low; Cheng Seong Khe; Chin Wei Lai; Sieh Kiong Tiong; Nowshad Amin

doi:10.1371/journal.pone.0228322

An investigation of the stirring duration effect on synthesized graphene oxide for dye-sensitized solar cells

PLoS One. 2020 Feb 3;15(2):e0228322. doi: 10.1371/journal.pone.0228322. eCollection 2020.

Authors

Xin Hui Yau^{1

2}, Foo Wah Low³, Cheng Seong Khe^{1

2}, Chin Wei Lai⁴, Sieh Kiong Tiong³, Nowshad Amin³

Affiliations

¹ Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Seri Iskandar, Perak, Malaysia.
² Centre of Innovative Nanostructures and Nanodevices (COINN), Universiti Teknologi PETRONAS, Seri Iskandar, Perak, Malaysia.
³ Institute of Sustainable Energy, Universiti Tenaga Nasional (The National Energy University), Jalan IKRAM-UNITEN, Kajang, Selangor, Malaysia.
⁴ Nanotechnology & Catalysis Research Centre (NANOCAT), Institute of Postgraduate Studies (IPS), University of Malaya, Kuala Lumpur, Malaysia.

Abstract

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Coloring Agents / chemistry*
Electric Power Supplies*
Graphite / chemistry*
Solar Energy*

Substances

Coloring Agents
graphene oxide
Graphite

Grants and funding

This research is supported financially by the Yayasan Universiti Teknologi PETRONAS (YUTP) Grant (YUTP 0153AA-E40), the Fundamental Research Grant Scheme (FRGS/1/2019/STG07/UTP/02/6), Universiti Tenaga Nasional BOLD2025 Grant (No. 10436494/B/2019097) and Universiti Tenaga Nasional BOLD2025 Publication (RJ010289176). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.