Ternary Nanocomposites of Porphyrin, Angular Au Nanoparticles and Reduced Graphene Oxide: Photocatalytic Synthesis and Enhanced Photocurrent Generation

Antibacterial Performance of a Gold-Loaded g-C3 N4 Nanocomposite System in Visible Light-Dark Dual Mode

Semiconductor photocatalysis technology, which can kill pathogenic microorganisms in a green and broad-spectrum way, is a new research field with great application potential. Due to the dependence on light, semiconductor materials have the problems of low utilization rate of sunlight and inactivation under dark conditions. A simple Au-loaded g-C₃ N₄ (Au/g-C₃ N₄ ) nanocomposites was studied. Under dark conditions, the antibacterial efficiency of 1.2 % Au/g-C₃ N₄ reached 99.1 % relative to 10⁵  CFU (Colony-FormingUnits)/mL E. coli. Under light conditions, the antibacterial efficiency of 0.9 % Au/g-C₃ N₄ reached 94.1 % relative to 10⁷  CFU/mL E. coli. The influence of contact time, Au loading and bacterial concentration on its antibacterial performance under dark conditions was discussed in detail. Through photoelectrochemistry, SEM, TEM and reactive oxygen species (ROS) detection the microscopic charge behaviour was revealed in the system, and a light-dark dual-mode antibacterial mechanism was proposed.

A novel three-dimensional pyridine-pillared graphene assembly for enhanced electron transfer and photocatalytic hydrogen evolution

Novel 1,2-di(pyridine-4-ly)ethyne pillared GO composites with high photocatalytic activity were achieved with rare earth ions as interfacial linkers.

Gas-phase rapid reduction of graphene oxide through photoionization of gold nanoparticles

This work introduces for the first time the rapid reduction of graphene oxide via the photoionization of gold nanoparticles in a continuous gas-phase process. Ejected electrons from gold nanoparticles facilitated the rapid photoinduced reduction of GO nanoflakes without the use of wet chemical processes.

A robust and efficient visible light driven photocatalyst for hydrogen evolution based on ruthenium dye N3 covalently immobilized on reduced graphene oxide

A robust and efficient photocatalyst based on ruthenium dye N3 covalently immobilized on reduced graphene oxide was used for photocatalytic hydrogen evolution.

3-Aminopropyltrimethoxysilane and graphene oxide/reduced graphene oxide-induced generation of gold nanoparticles and their nanocomposites: electrocatalytic and kinetic activity

The role of graphene oxide (GO)/reduced graphene oxide (rGO) in the 3-aminopropyltrimethoxysilane-mediated synthesis of gold nanoparticles in the presence of formaldehyde is reported.

Silicon phthalocyanine covalently functionalized N-doped ultrasmall reduced graphene oxide decorated with Pt nanoparticles for hydrogen evolution from water

To improve the photocatalytic activity of graphene-based catalysts, silicon phthalocyanine (SiPc) covalently functionalized N-doped ultrasmall reduced graphene oxide (N-usRGO) has been synthesized through 1,3-dipolar cycloaddition of azomethine ylides. The obtained product (N-usRGO/SiPc) was characterized by transmission electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, Raman spectra, X-ray photoelectron spectroscopy, fluorescence, and UV-vis spectroscopy. The results demonstrate that SiPc has been successfully grafted on the surface of N-usRGO. The N-usRGO/SiPc nanocomposite exhibits high light-harvesting efficiency covering a range of wavelengths from the ultraviolet to visible light. The efficient fluorescence quenching and the enhanced photocurrent response confirm that the photoinduced electron transfers from the SiPc moiety to the N-usRGO sheet. Moreover, we chose Pt nanoparticles as cocatalyst to load on N-usRGO/SiPc sheets to obtain the optimal H2 production effect. The platinized N-usRGO/SiPc (N-usRGO/SiPc/Pt) demonstrates good hydrogen evolution performance under both UV-vis and visible light (λ>400 nm) irradiation. The apparent quantum yields are 1.3% and 0.56% at 365 and 420 nm, respectively. These results reveal that N-usRGO/SiPc/Pt nanocomposite, consolidating the advantages of SiPc, N-usRGO, and Pt NPs, can be a potential candidate for hydrogen evolution from water under UV-vis or visible light irradiation.

Reduction degree and property study of graphene nanosheets prepared with different reducing agents and their applicability as a carrier of the Ru(phen)3Cl2 luminescent sensor for DNA detection

Recently, graphene nanosheets (GNS) have been widely investigated and used in capacitors, catalysts, biological/chemical sensors, etc.

Microwave-assisted synthesis of 6,6′-(aryl(alkyl)methylene)bis(2,4-dialkylphenol) antioxidants catalyzed by multi-sulfonated reduced graphene oxide nanosheets in water

Sulfonated reduced graphene oxide nanosheets were characterized and employed in the synthesis of bisphenolic antioxidants in water under microwave conditions.

Biogenic gold nanoparticles-reduced graphene oxide nanohybrid: synthesis, characterization and application in chemical and biological reduction of nitroaromatics

The biogenic AuNPs/rGO can participate in and accelerate electron transfer, and catalyze both chemical and biological reduction of nitroaromatics efficiently.

High-efficiency plasmon-enhanced and graphene-supported semiconductor/metal core-satellite hetero-nanocrystal photocatalysts for visible-light dye photodegradation and H2 production from water

Solar-driven photocatalytic process based on electron-hole pair production in semiconductors is a long sought-after solution to a green and renewable energy and has attracted a renaissance of interest recently. The relatively low photocatalytic efficiency, however, is a main obstacle to their practical applications. A promising attempt to solve this problem is by combined use of metal nanoparticles, by taking advantage of strong and localized plasmonic near-field to enhance solar absorption and to increase the electron-hole pair generation rate at the surface of semiconductor. Here, we report a semiconductor/metal visible-light photocatalyst based on CdSe/CdS-Au (QD-Au) core-satellite heteronanocrystals, and assemble them on graphene nanosheets for better photocatalytic reaction. The as-synthesized photocatalyst exhibits excellent plasmon-enhanced photocatalytic activities toward both photodegradation of organic dye and visible-light H2 generation from water. The H2 evolution rate achieves a maximum of 3113 μmol h(-1) g(-1) for the heteronanocrystal-graphene composites, which is about 155% enhancement compared to nonplasmonic QD-G sample and 340% enhancement compared to control QD-Au-G sample, and the apparent quantum efficiency (QE) reaches to 25.4% at wavelength of 450 nm.

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

Reduced graphene oxide/Ag nanoparticles hybrids (rGO/AgNPs) were fabricated via a green and facile hydrothermal method. The as-synthesized materials were characterized in detail using various spectroscopic and microscopic techniques. Under a suitable dosage of silver ions, well-dispersed AgNPs on the reduced graphene oxide sheets were obtained. The surface plasmon resonance properties of AgNPs on graphene show that there is an interaction between AgNPs and graphene. Trace detection of organic dyes is studied based on rGO/AgNPs hybrids as efficient surface enhanced Raman scattering platforms. It has been found that the suitable experiment parameter is crucial to trace detection of organic dyes molecules. This work is of importance in the practical application in device-design based on the SERS effect of noble metal/reduced oxide graphene (or oxide graphene) hybrids.

Three-dimensional porous supramolecular architecture from ultrathin g-C(3)N(4) nanosheets and reduced graphene oxide: solution self-assembly construction and application as a highly efficient metal-free electrocatalyst for oxygen reduction reaction

Direct mixing of aqueous dispersions of ultrathin g-C3N4 nanosheets and graphene oxide (GO) under ultrasonication leads to three-dimensional (3D) porous supramolecular architecture. Photoreduction of GO yields conductive porous g-C3N4/rGO hybrid. The resulting 3D architecture possesses high surface area, multilevel porous structure, good electrical conductivity, efficient electron transport network, and fast charge transfer kinetics at g-C3N4/rGO interfaces, which facilitate the diffusion of O2, electrolyte, and electrons in the porous frameworks during oxygen reduction reaction (ORR). Ultrathin g-C3N4 nanosheet also causes effective electron tunneling through g-C3N4 barrier, leading to rich electrode-electrolyte-gas three-phase boundaries, and shortens the electron diffusion distance from rGO to O2. As a novel ORR catalyst, such 3D hybrid exhibits remarkable catalytic performance, outperformed other g-C3N4/rGO composites, and exhibits excellent durability.

Au-nanoparticle-loaded graphitic carbon nitride nanosheets: green photocatalytic synthesis and application toward the degradation of organic pollutants

Au nanoparticles (AuNPs) were loaded on graphitic carbon nitride (g-C3N4) nanosheets prepared by ultrasonication-assisted liquid exfoliation of bulk g-C3N4 via green photoreduction of Au(III) under visible light irradiation using g-C3N4 as an effective photocatalyst. The nanohybrids show superior photocatalytic activities for the decomposition of methyl orange under visible-light irradiation to bulk g-C3N4, g-C3N4 nanosheets, and AuNP/bulk g-C3N4 hybrids.