Improving the Visible Light Photoactivity of In₂S₃–Graphene Nanocomposite via a Simple Surface Charge Modification Approach

Abstract

We report an efficient and easily accessible self-assembly route to synthesize In2S3-GR nanocomposites via electrostatic interaction of positively charged In2S3 nanoparticles with negatively charged graphene oxide (GO) followed by a hydrothermal process for reduction of GO to graphene (GR). The as-synthesized In2S3-GR nanocomposites exhibit much higher visible light photocatalytic activity toward selective reduction of nitroaromatic compounds in water than bare In2S3 nanoparticles and In2S3-GR-H that is obtained from the simple "hard" integration of GR nanosheets with solid In2S3 nanoparticles without modification of surface charge. On the basis of the joint characterizations and structure-photoactivity correlation it is disclosed that the enhanced photocatalytic performance of In2S3-GR is mainly ascribed to the more efficient interfacial contact between In2S3 and the GR nanosheets than In2S3-GR-H, which would amplify the use of electron conductivity and mobility of GR to improve the lifetime and transfer of photogenerated charge carriers more efficiently and thus boost the photoactivity more effectively. This work highlights the significant effect of preparation methods on the photoactivity of GR-semiconductor nanocomposites. It is expected that such a simple electrostatic self-assembly strategy could aid to rationally fabricate more efficient GR-semiconductor nanocomposites with improved interfacial contact and photocatalytic performance toward various photocatalytic selective transformations.

CTAB-assisted synthesis of S@rGO composite with enhanced photocatalytic activity and photostability

“…It is observed that, after wrapped by rGO, though in small amount, such as 1 wt%, the intensity of PL spectra diminished significantly, indicating a drastic fluorescence quenching effect of rGO [28,29]. This result indicates that the recombination of electron-hole pairs is effectively suppressed and the lifetime of photogenerated electron-hole pairs is prolonged [30,31]. The quenching mechanism of PL spectra can be attributed to the high carrier mobility of rGO, which could trap or shuttle the photogenerated electrons from sulfur and retard the recombination of electron-hole pairs, and thus contribute to the photocatalytic activity enhancement of the S@rGO composites [32,33].…”

Enhanced Photocatalytic Performance of ZnO through Coupling with Carbon Materials

“…[45][46][47][48][49][50] Figure 3 The structures of fullerene, carbon nanotube, and graphene. [47] Fullerene (C 60 ) has received great interests by researchers due to its unique electronic and structural properties.…”

Water Splitting By Photocatalytic Reduction

“…So far, many low-dimensional hybrid photocatalysts such as 0D-1D [183][184][185], 0D-2D [186][187][188][189], 1D-1D [190], 1D-2D [191][192][193][194][195][196][197], and 2D-2D [163,164,198,199] have been constructed and applied in environmental and clean energy areas. Here, we focus on the 0D-2D and 2D-2D hybrids and multijunction photocatalysts.…”