In this review, for a variety of metals and semiconductors, an attempt is made to generalize observations in the literature on the effect of process conditions applied during photodeposition on (i) particle size distributions, (ii) oxidation states of the metals obtained, and (iii) consequences for photocatalytic activities. Process parameters include presence or absence of (organic) sacrificial agents, applied pH, presence or absence of an air/inert atmosphere, metal precursor type and concentration, and temperature. Most intensively reviewed are studies concerning (i) TiO2; (ii) ZnO, focusing on Ag deposition; (iii) WO3, with a strong emphasis on the photodeposition of Pt; and (iv) CdS, again with a focus on deposition of Pt. Furthermore, a detailed overview is given of achievements in structure-directed photodeposition, which could ultimately be employed to obtain highly effective photocatalytic materials. Finally, we provide suggestions for improvements in description of the photodeposition methods applied when included in scientific papers.

Methods, Mechanism, and Applications of Photodeposition in Photocatalysis: A Review.

In this study, an investigation on the characterization of reduced graphene oxides (rGOs) prepared from natural graphites with different graphitization degrees using Hummers method was conducted. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, atomic force microscopy and electrochemical performance were performed to characterize the as-prepared graphene oxides (GOs) and rGOs. The results demonstrate that graphites with a lower graphitization degree are more easily oxidized due to the active carbon atoms exposed on their edges and the effective diffusion of oxidants that intercalate into the graphitic layers. In addition, graphites with a low graphitization degree were more suitable for the synthesis of thin layer graphene with a high defect degree and small size in the in-plane sp2 domains as well as a relatively high specific capacitance.

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Comparison of the characteristic properties of reduced graphene oxides synthesized from natural graphites with different graphitization degrees

Surface-enhanced Raman scattering (SERS) is increasingly becoming an important analytical technique in various fields, which can mostly be attributed to the significant evolution of SERS-active substrates. The semiconductor-based SERS technique is particularly interesting because the inherent physicochemical properties of semiconductor materials offer several possibilities for the development and improvement of SERS-based analytical techniques. According to the effect of the semiconductor materials in SERS, semiconductor-based SERS techniques can be categorized into two areas: (1) semiconductor-enhanced Raman scattering, in which a semiconductor material is directly used as a substrate for enhancing Raman signals of adsorbed molecules, and (2) semiconductor-mediated-enhanced Raman scattering, in which a semiconductor is employed as an ‘antenna’ or ‘trap’ to modulate the Raman enhancement originating from a metal substrate. While the theory on semiconductor-based SERS is still incomplete and evolving, semiconductor-based SERS techniques have already resulted in substantial progress in biological analysis, photocatalysis, solar cells, sensing, and optoelectronic devices. The aim of this review is to outline the recent progress in this emerging research field, with a special emphasis on its analytical performance and application areas. Copyright © 2015 John Wiley & Sons, Ltd.

Semiconductor materials in analytical applications of surface‐enhanced Raman scattering

Graphene has been employed as an excellent support for metal nanomaterials because of its unique structural and physicochemical properties. Silver nanoparticles (AgNPs) with exceptional properties have received considerable attention in various fields; however, particle aggregation limits its application. Therefore, the combination of AgNPs and graphene based nanocomposites (Ag-graphene based nanocomposites) has been widely explored to improve their properties and applications. Excitingly, enhanced antimicrobial, catalytic, and surface enhanced Raman scattering properties are obtained after their combination. In order to have a comprehensive knowledge of these nanocomposites, this Review highlights the chemical and biological synthesis of Ag-graphene nanocomposites. In particular, their applications as antimicrobial agents, catalysts, and sensors in biomedicine, agricultural protection, and environmental remediation and detection are covered. Meanwhile, the factors that influence the synthesis and applications are also briefly discussed. Furthermore, several important issues on the challenges and new directions are also provided for further development of these nanocomposites.

Advancement of Ag-Graphene Based Nanocomposites: An Overview of Synthesis and Its Applications.

Nanoparticle-based antibacterial agents have emerged as an interdisciplinary field involving medicine, material science, biology, and chemistry because of their size-dependent qualities, high surface-to-volume ratio, and unique physiochemical properties. Some of them have shown great promise for their application in plant protection and nutrition. Here, GO-AgNPs nanocomposite was fabricated through interfacial electrostatic self-assembly and its antifungal activity against phytopathogen Fusarium graminearum was investigated in vitro and in vivo for the first time. The results demonstrated that the GO-AgNPs nanocomposite showed almost a 3- and 7-fold increase of inhibition efficiency over pure AgNPs and GO suspension, respectively. The spore germination inhibition was stimulated by a relatively low concentration of 4.68 μg/mL (minimum inhibition concentration (MIC)). The spores and hyphae were damaged, which might be caused by an antibacterial mechanism from the remarkable synergistic effect of GO-AgNPs, i...

Graphene Oxide-Silver Nanocomposite: Novel Agricultural Antifungal Agent against Fusarium graminearum for Crop Disease Prevention

Space-Confined Yolk-Shell Construction of Fe3O4 Nanoparticles Inside N-Doped Hollow Mesoporous Carbon Spheres as Bifunctional Electrocatalysts for Long-Term Rechargeable Zinc–Air Batteries

A facile and green method for synthesis of reduced graphene oxide/Ag hybrids as efficient surface enhanced Raman scattering platforms.

In situ confinement growth of peasecod-like N-doped carbon nanotubes encapsulate bimetallic FeCu alloy as a bifunctional oxygen reaction cathode electrocatalyst for sustainable energy batteries

Wenxian Wei

Papers

Space-Confined Yolk-Shell Construction of Fe3O4 Nanoparticles Inside N-Doped Hollow Mesoporous Carbon Spheres as Bifunctional Electrocatalysts for Long-Term Rechargeable Zinc–Air Batteries

A facile and green method for synthesis of reduced graphene oxide/Ag hybrids as efficient surface enhanced Raman scattering platforms.

In situ confinement growth of peasecod-like N-doped carbon nanotubes encapsulate bimetallic FeCu alloy as a bifunctional oxygen reaction cathode electrocatalyst for sustainable energy batteries

Rapid fabrication of silver nanoparticle-coated filter paper as SERS substrate for low-abundance molecules detection

Preparation of cellophane-based substrate and its SERS performance on the detection of CV and acetamiprid.