A multifunctional Ag/TiO₂/reduced graphene oxide with optimal surface‐enhanced Raman scattering and photocatalysis

Abstract

A multifunctional Ag/TiO 2 /reduced graphene oxide (rGO) ternary nanocomposite was prepared by a one-step photochemical reaction with TiO 2 and Ag nanoparticles successively deposited on reduced graphene oxide. The structure, morphology, composition, optical, and photoelectrochemical properties of Ag/TiO 2 /rGO were investigated in detail. Meanwhile, the ternary nanocomposite possessed much higher adsorption capacity to organic dyes compared with bare TiO 2 and binary Ag/TiO 2 , which would help to its use for surface-enhanced Raman scattering detection and photocatalytic degradation. Due to the charge transfer between rGO and organic dyes and enhanced electromagnetic mechanism of Ag, Ag/TiO 2 / rGO nanocomposites as surface-enhanced Raman scattering substrates demonstrated dramatically improved sensitivity and good uniformity. The detection limit of rhodamine 6G (R6G) was as low as 10 −9 mol/L, and the relative standard deviation values of the intensities remained below 5%. Most importantly, the synergistic coupling effect of three components extended the photoresponse range and accelerated separation of the electron-hole pairs, leading to greatly improved photocatalytic activity under simulated sunlight. The maximum rate constant (k, 0.06243 min −1 ) of Ag/TiO 2 /rGO was 50 and four times higher than that of TiO 2 and Ag/TiO 2 , respectively. K E Y W O R D Sadsorption, graphene oxide, photocatalysis, surface-enhanced Raman scattering property, titanium oxide

Bioinspired alumina/reduced graphene oxide fibrous monolithic ceramic and its fracture responses

“…The Raman spectrum is one of the most powerful characterization techniques for carbon materials . Figure shows the Raman spectra of the boundary before and after sintering, and the typical Raman spectrum of GO with D peak at 1356 cm −1 and G peak at 1598 cm −1 are depicted (Figure , curve a) . The Raman spectrum of the boundary after sintering showed a 2D peak at 2693 cm −1 except for the D and G peaks (Figure , curve b), thereby indicating three representative characteristic peaks of graphene appeared.…”

“…26,27 Figure 3 shows the Raman spectra of the boundary before and after sintering, and the typical Raman spectrum of GO with D peak at 1356 cm −1 and G peak at 1598 cm −1 are depicted ( Figure 3, curve a). 28 The Raman spectrum of the boundary after sintering showed a 2D peak at 2693 cm −1 except for the D and G peaks (Figure 3, curve b), thereby indicating three representative characteristic peaks of graphene appeared. The intensity ratio of the D and G peaks (I D /I G ) was smaller than that of GO, which indicated that part of sp 3 hybridization was converted to sp 2 hybridization.…”

Construction of Ag-modified TiO2/ZnO heterojunction nanotree arrays with superior photocatalytic and photoelectrochemical properties

“…The size of Ag NPs obtained by photodeposition has been reported to be 5-15 nm. 37 Fig. 3(c) is an SEM image of ZnO nanoparticles xed on FTO glass grown from TiO 2 nanorods by sol-gel method, it can be seen from the image that the ZnO nanoparticles are wrapped around the TiO 2 nanorods.…”

“…4(a), the diameter of the surface Ag NPs distributed on the ZnO nanorods is about 10-20 nm, which is in agreement with what has been reported in the literature. 37 This can reect the ZnO nanorods to provide more adhesion area for Ag quantum dots, which will be benecial to the SPR effect of Ag, photoelectrochemical performance and photocatalytic efficiency.…”

Enhancement of photocatalytic and photoelectrochemical properties of BiOI nanosheets and silver quantum dots co‐modified TiO2 nanorod arrays

“…When studying the catalytic performance of the sample, methyl orange was selected as the target contaminant to explore the PC activity under simulated sunlight. [] The auto‐degradation of contaminants (MO) can be ignored under light conditions. Figure B shows the efficiency of the photodegradation of different samples under UV irradiation.…”