Open AccessFacile and Green Fabrication of Microwave-Assisted Reduced Graphene Oxide/Titanium Dioxide Nanocomposites as Photocatalysts for Rhodamine 6G Degradation
Author(s) -
Andri Hardiansyah,
William Justin Budiman,
Nurfina Yudasari,
Isnaeni Isnaeni,
Tetsuya Kida,
Arie Wibowo
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c04966
Subject(s) - graphene , materials science , photocatalysis , nanocomposite , anatase , titanium dioxide , rhodamine b , rhodamine 6g , oxide , chemical engineering , scanning electron microscope , raman spectroscopy , transmission electron microscopy , nanotechnology , composite material , catalysis , organic chemistry , chemistry , metallurgy , engineering , physics , molecule , optics
Organic pollutants, such as synthetic dyes, are treated to prevent them from contaminating natural water sources. One of the treatment methods is advanced oxidation process using a photocatalyst material as the active agent. However, many photocatalysts are hindered by their production cost and efficiency. In this study, nanocomposites consisting of reduced graphene oxide and titanium dioxide (rGO/TiO 2 ) were prepared by a simple and green approach using the microwave-assisted method, and we utilized a graphene oxide (GO) precursor that was fabricated through the Tour method. The ratios of rGO/TiO 2 in nanocomposites were varied (2:1, 1:1, and 1:2) to know the influence of rGO on the photocatalytic performance of the nanocomposites for rhodamine 6G degradation. Transmission electron microscopy (TEM) observation revealed that a transparent particle with a sheetlike morphology was detected in the rGO sample, suggesting that a very thin film of a few layers of GO or rGO was successfully formed. Based on scanning electron microscopy (SEM) observation, the rGO/TiO 2 nanocomposites had a wrinkled and layered rGO structure decorated by TiO 2 nanoparticles with average diameters of 125.9 ± 40.6 nm, implying that rGO layers are able to prevent TiO 2 from agglomeration. The synthesized product contained only rGO and TiO 2 in the anatase form without impurities that were proven by Raman spectra and X-ray diffraction (XRD). The nanocomposite with rGO/TiO 2 ratio 1:2 (composite C) was found to be the best composition in this study, and it was able to degrade 82.9 ± 2.4% of the rhodamine 6G after UV irradiation for 4 h. Based on a time-resolved photoluminescence study at wavelength emission 500 nm, the average decay lifetime of R6G-rGO/TiO 2 composites (2.91 ns) was found to be longer than that of the R6G-TiO 2 sample (2.05 ns), implying that the presence of rGO in rGO/TiO 2 composites successfully suppressed the electron-hole recombination process in TiO 2 and significantly improved their photocatalytic performance. This study showed that the rGO/TiO 2 nanocomposites synthesized through relatively simple and eco-friendly processes display promising prospects for photocatalytic degradation of dyes and other recalcitrant pollutants in a water stream.