Graphene Oxide Enwrapped Ag/AgX (X = Br, Cl) Nanocomposite as a Highly Efficient Visible-Light Plasmonic Photocatalyst

Abstract

In this paper, we have reported that well-defined graphene oxide (GO) enwrapped Ag/AgX (X = Br, Cl) nanocomposites, which are composed of Ag/AgX nanoparticles and gauze-like GO nanosheets, could be facilely fabricated via a water/oil system. We have shown that thus-synthesized GO-based hybrid nanocomposites could be used as a stable plasmonic photocatalyst for the photodegradation of methyl orange (MO) pollutant under visible-light irradiation. Compared with the corresponding bare Ag/AgX nanospecies, the GO-involved nanocomposites (Ag/AgX/GO) display distinctly enhanced photocatalytic activities. The hybridization of Ag/AgX with GO nanosheets causes the nice adsorptive capacity of Ag/AgX/GO to MO molecules, the smaller size of the Ag/AgX nanoparticles in Ag/AgX/GO, the facilitated charge transfer, and the suppressed recombination of electron-hole pairs in Ag/AgX/GO. It is suggested that these multifactors, resulting from the hybridization of GO, contribute to the enhanced photocatalytic performance observed from Ag/AgX/GO. The investigation likely opens up new possibilities for the development of original yet highly efficient and stable GO-based plasmonic photocatalysts that utilize visible light as an energy source.

Synthesis and Characterization of Novel Plasmonic Ag/AgX-CNTs (X = Cl, Br, I) Nanocomposite Photocatalysts and Synergetic Degradation of Organic Pollutant under Visible Light

“…14 Another recent work report also indicated that a nanocomposites made of Ag/AgX loaded graphene oxide (GO) (Ag/AgX@GO) has significantly enhanced photocatalytic activity and stability as compared to those of bare Ag/AgX (X = Cl, Br) plasmonic photocatalysts. 16 These research findings imply that the photocatalytic activity as well as the stability of Ag/AgX can be significantly enhanced by loading onto a suitable supporting material.…”

“…Generally, the bare AgX (X = Cl, Br, I) samples could exhibit distinct adsorption only in the UV region but limited in the VL region. 13,16,32,33 However, the Ag/AgBr-CNTs photocatalyst has apparent absorption intensity in VL region with a significant enhancement (Figure 4a). Similar results were also obtained for Ag/AgCl-CNTs and Ag/AgI-CNTs (Figure 4b, c).…”

“…47,48 Therefore, it is sound to believe that a reinforced charge transfer and separation could be obtained in Ag/AgBr-CNTs hybrid nanocomposites, where Ag/AgBr and CNTs might act as e − donor and e − acceptor, respectively. 16 Although this newly prepared photocatalyst is relatively efficient for degradation of TBP and stable under VL, the deactivation mechanism of the photocatalyst should be investigated. The slight reduce of the photocatalytic performance during the photocatalyst recycling reactions could be the loss of small part of Ag + on the photocatalyst surface during light irradiation, since Ag + could be reduced to metallic Ag(0) by photogenerated e − , which can be verified by XRD and XPS analyses of prepared photocatalyst after reuse.…”

Preparation of Nanosized Palladium-Graphene Composites and Photocatalytic Degradation of Various Organic Dyes

“…[4][5][6] Graphene is a two-dimensional free-standing substance with a single-layer structure that has become one of the most popular topics in the fields of chemistry, biochemistry, nanotechnology, physics, and materials science. 7 The combination of graphene with nanosized metal particles has been performed many times in research over the last decade owing to their novel optical, catalytic, mechanical, and electronic properties. 6,8 Graphene has also attracted a lot of attention as a single layer of sp 2 -bonded carbon with zero band gap compacted into a two-dimensional honeycomb structure.…”

“…[9][10][11] Among the nanosized composites, graphene can work as a high-performance supporting material because of its two-dimensional structure; therefore, it has various applications in fields like photocatalysis, sensing, and optics. [5][6][7]9,[11][12][13][14][15][16][17] Nanosized metal particles can be dispersed homogeneously on the plane of graphene, and charge transfer at the interface of these hybrid materials can provide a synergistic effect inducing properties that are dissimilar from those of each individual component. 13,[18][19][20][21] Therefore, in this study, the photocatalytic activity of nanosized palladium-graphene composites was evaluated in the degradation of organic dyes methylene blue (MB), methyl orange (MO), rhodamine B (RhB), and brilliant green (BG) using a UV-vis spectrophotometer under ultraviolet light at 254 nm.…”