Ag Nanoparticle-decorated Graphene Oxide Research Articles

Combination of MoS2 nanopetals with Ag nanoparticles decorated graphene oxide for boosting photocatalytic abatement of recalcitrant pollutants under visible light irradiation

Herein, various weight ratios (1:1, 1:3, and 3:1) of MoS2/GO composites decorated with Ag nanoparticles (named as MAG) have been prepared by microwave-assisted route. XRD and XPS investigations indicated the catalyst crystallinity and elemental oxidation states. Morphological analysis revealed presence of small MoS2 nanopetals scattered on GO sheets with Ag NPs dispersed on surface whereas BET-analysis disclosed its excellent surface area (∼88 m2/g). Optical properties of MAG catalysts revealed that they were highly visible-light active, with a bandgap of 2.15 eV and a lower charge recombination rate. Excellent efficiency was observed for TC (90.7%; 0.0186 min−1) and FIP-degradation (85.2%; 0.0177 min−1) with 4 mg MAG (3:1) catalyst at neutral pH under visible-light irradiation owing to high synergistic interaction (∼2.21) in the composite. Effects of catalyst amount, pH, and effective area of illumination on degradation were investigated. High reusable nature of the catalyst (65% (TC) and 58% (FIP) efficiency after 5 cycles) was supported by post-photocatalytic characterization studies. Photodegradation products of TC were determined via LC-MS studies. Holes and hydroxyl radicals were majorly involved in degradation process revealed by trapping studies. High COD (70.4%) and TOC (55.1%) removal rates confirm high photo-mineralization of real-wastewater without any pre-treatment. The current investigation, combined with comparative literature, illustrates real-world potential of MAG catalysts for eradication of resistant pollutants.

A digoxin electrochemical aptasensor using Ag nanoparticle decorated graphene oxide

In this work, a highly sensitive aptasensor for digoxin determination in biological samples has been introduced.

Graphene oxide shell-isolated Ag nanoparticles for surface-enhanced Raman scattering

An efficient surface enhanced Raman scattering (SERS) substrate has been developed based on Ag nanoparticle-decorated graphene oxide (GO). The structure of Ag@GO hybrid material was confirmed by X-ray diffraction, transmission and scanning electron microscopy. The as-prepared substrate exhibited the enhancement ability of SERS toward various aromatic dyes, such as Rhodamine 6G, Rhodamine B, and crystal violet. The enhanced Raman signals could be due to the presence of an ultrathin GO shell with 2.8nm in thickness. In particular, the GO shell could efficient to maintain chemical and optical stability, and improved biocompatibility for this SERS-activity material.

Synergistic effect of Ag nanoparticle-decorated graphene oxide and carbon fiber on electrical actuation of polymeric shape memory nanocomposites

This study reports an effective approach of significantly improving electrical properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by electrically resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, respectively. A layer of Ag nanoparticles was synthesized from Ag+ solution and chemically deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the electrical conductivity. The experimental results reveal that the electrical conductivity of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the electrically induced shape memory effect of the SMP nanocomposite was achieved, and the temperature distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electro-activated SMP nanocomposites and the resistive Joule heating was viable at a low electrical voltage below 10 V.

Amperometric detection of Sudan I in red chili powder samples using Ag nanoparticles decorated graphene oxide modified glassy carbon electrode

A simple and sensitive electrochemical method was developed to determine the concentration of Sudan I in chili powder based on silver nanoparticles decorated graphene oxide modified glassy carbon electrode (AgNPs@GO/GCE). The voltammetry behaviour of Sudan I on modified GCE was investigated in phosphate buffer medium (PBS) with various pH ranges and the electron transfer properties were studied. It is found that the AgNPs@GO/GCE can catalyse the reduction of azo group, NN followed by electrochemical oxidation of -OH group present in Sudan I dye molecule. Quantitative detection of Sudan I present in food products was carried out by amperometry method in which reduction potential was fixed at −0.77V vs. Ag/AgCl. The amperometry method showed an excellent performance with a sensitivity of 6.83μAmM−1 and a detection limit of 11.4×10−7ML−1. A linear calibration graph was constructed in the ranging 3.90×10−6 to 3.19×10−5ML−1. The method was successfully applied for the determination of Sudan I in red chili powder samples.

Method for effective immobilization of Ag nanoparticles/graphene oxide composites on single-stranded DNA modified gold electrode for enzymeless H2O2 detection

In this paper, we report a new method for effective immobilization of Ag nanoparticles (AgNPs) decorated graphene oxide (AgNP/GO) composites onto thiolated single-stranded DNA decorated Au electrode (AuE) surface. The novel immobilization method is based on the coordination interactions and π–π stacking interactions between DNA bases and AgNP/GO composites. The morphologies of the AgNP/GO nanocomposites are characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It is found that the AgNP/GO-decorated AuE exhibits remarkable catalytic performance for H2O2 reduction. This H2O2 sensor has a fast amperometric response time of less than 5 s. The linear range is estimated to be from 0.1 mM to 20 mM (r = 0.998) and the detection limit is estimated to be 1.9 μM at a signal-to-noise ratio of 3, respectively.