TiO2–rGO nanocomposites with high rGO content and luminescence quenching through green redox synthesis

Bandgap Variations and Photodegradation Efficiency on Inclusion of SiO2 in TiO2-rGO Nanocomposite for High Performance Photocatalysis

“…Pure anatase phase of TG4 was previously confirmed by the corresponding XRD pattern in Fig. 1(a) [8]. In TGS nanocomposites, the intensity of TiO2 peaks were drastically reduced and changed to single peak that was amorphous in nature, as SiO2 concentration was increased.…”

“…This was close to 100% degradation reported for the same dye using TG4 photocatalyst used in our previous study, and conducted under similar experimental conditions. The result was also much higher than 80% degradation shown by TiO2 NCs [8]. The adsorption of TGS4 catalyst at the end of 150 min in dark was 67.27% (not shown here).…”

“…In TGS nanocomposites, the intensity of TiO2 peaks were drastically reduced and changed to single peak that was amorphous in nature, as SiO2 concentration was increased. The single peak at 25.3 ⁰ also overlapped with those of rGO (002) and TiO2(101) in all the TGS nanocomposites [8], and no distinct peaks of rGO and SiO2 were seen. Additionally, the (100) diffraction peak of rGO at 43 ⁰ vanished in the TGS nanocomposites [9].…”

“…rGO acts as an efficient cover and protection for the catalyst species, increasing their surface area and improving the charge carrier separation and transport [7]. High photoactivity was reported for 47% rGO-TiO2 nanocomposite (TG4) in our previous study [8]. We are investigating here the TiO2-rGO-SiO2 (TGS) nanocomposites for improving the performance of the photocatalyst.…”

“…TG4 nanocomposites were further prepared using ascorbic acid as green reducing agent. The specific details of the above could be found in our previous study [8]. For TGS nanocomposites, a fixed amount of GO was initially added to 100 ml of ethanol and mixed for 2 h. Variable volumes of TEOS solutions (1 ml, 2 ml, 3 ml and 4 ml) were added separately to four distinct sets of GO solutions with comparable volumes and specified amounts (mole) of TTIP based on weight % ratio at 40 0 C. Ascorbic acid (0.01 M) was added to each as a reducing agent and stirred for 18 h. The gel obtained was aged at RT, filtered, rinsed in deionized water and dried.…”