Facile preparation of surfactant-free Au NPs/RGO/Ni foam for degradation of 4-nitrophenol and detection of hydrogen peroxide

Abstract

The application of Au nanoparticles (Au NPs) often requires surface modification with chemical surfactants, which dramatically reduce the surface activity and increase the chemical contamination and cost of Au NPs. In this research, we have developed a novel Au NPs/reduced graphene oxide/Ni foam hybrid (Au NPs/RGO/NiF) by in situ reduction through ascorbic acid and replacement reaction. This method is green, facile and efficient. The Au NPs are free of chemical surfactants and are homogeneously distributed on the surface of the RGO/NiF. The as-prepared Au NPs/RGO/NiF hybrid is uniform, stable and exhibits not only a high reduction efficiency for the reduction of 4-nitrophenol with a catalytic kinetic constant of up to 0.46 min (0.15 cm catalysis) but also a sensitive and selective detection of HO with a detection limit of ∼1.60 μM.

Au-Decorated N-Rich Carbon Dots as Peroxidase Mimics for the Detection of Acetylcholinesterase Activity

“…In particular, gold nanoparticles or nanoclusters (Au NPs/NCs) exhibit excellent peroxidase-mimicking activity, good biocompatibility, and flexible modification on the surface . However, as Au NPs/NCs tend to aggregate easily due to the high surface energy, the prepared Au NPs/NCs require the protection of ligands or capping agents like macromolecules. , Usually, the catalytic reaction takes place on the surface, and the coating ligands used to protect Au NPs/NCs may block certain active sites on the surface, further reducing the catalytic activity. − Besides, previous studies have shown that the catalytic activity of Au NPs/NCs is correlated with size, and the smaller the size, the more the active sites are generally exposed, and potentially higher the catalytic efficiency.…”

Porous Montmorillonite@Graphene Oxide@Au Nanoparticle Composite Microspheres for Organic Dye Degradation

“…Gold nanoparticles (Au NPs) with sizes between 1 and 100 nm have received tremendous attention due to their remarkable catalytic, electronic, and magnetic activities, which make them attractive targets for various applications. − Their application in catalytic reduction of oragnic dyes to inactive substance is significant important because most of organic dyes are carcinogenic and very low concentration in water will cause health-risk problems . While Au NPs contain many active sites that enhance their catalytic activity compared with bulk Au, the high surface energy of Au NPs often leads to aggregation, which greatly reduces their catalytic efficiency. − To improve the stability of Au NPs catalysts, various substrates such as carbon materials, silica materials, metal–organic frameworks, metal oxides, metal hydroxides, clay, and polymers have been used to immobilize Au NPs on their surfaces. − Among these materials, graphene oxide (GO) has been shown to be a highly efficient carbon support for fabricating GO@Au NPs nanocomposites. ,− Its large specific surface area and structural defects in its lattice provide abundant reactive sites to bind and support many Au NPs. These properties increase the electrical conductivity and electrical transfer of the catalyst, thus increasing its catalytic activity toward organic contaminants .…”

Fabrication of Robust Paper-Based Electronics by Adapting Conventional Paper Making and Coupling with Wet Laser Writing

“…As a proof of concept, we evaluated our paper-based electrode (patterned with Au NPs/rGO/cellulose regions) for the electrochemical analysis using the commonly studied analyte H 2 O 2 . − In our initial study, we added a drop of H 2 O 2 -containing phosphate-buffered solution (PBS, pH 7) to our electrode and performed CV measurements, as shown in Figure a. The CV response for one electrode shows a systematic increase in current with liquid drops containing increasing levels of H 2 O 2 .…”

“…Selectivity was assessed using (d) common interfering compounds and (e) a complex background matrix (i.e., milk). (f) Comparison of the performance of our paper-based electrode for H 2 O 2 detection (LOD is the limit of detection). − …”