Jing-Jing Lv

One-pot green synthesis of nitrogen-doped carbon nanoparticles as fluorescent probes for mercury ions

Herein, a simple, green, and low-cost way was developed in the synthesis of fluorescent nitrogen-doped carbon nanoparticles (FNCPs) with nitrogen content of 6.88%, using one-pot hydrothermal treatment of strawberry juice. The as-prepared FNCPs exhibited a maximum emission at 427 nm with a quantum yield of 6.3%, which could be specifically quenched by Hg2+. This phenomenon was used to develop a fluorescent method for facile detection of Hg2+ with a linear range from 10 nM to 50 μM and a detection limit of 3 nM (S/N = 3), and further extended to measure environmental water samples with satisfactory recovery. This study provides a green strategy in the synthesis of FNCPs to detect Hg2+ with good performance.

One-pot synthesis of porous Pt–Au nanodendrites supported on reduced graphene oxide nanosheets toward catalytic reduction of 4-nitrophenol

In this work, a facile, convenient and effective one-pot wet-chemical method was developed for preparation of well-dispersed porous bimetallic Pt–Au alloyed nanodendrites uniformly supported on reduced graphene oxide nanosheets (Pt–Au pNDs/RGOs) at room temperature. The fabrication strategy was efficient and green owing to the use of cytosine as a structure-directing agent and weak stabilizing agent, without employing any organic solvent, template, seed, surfactant, or complicated apparatus. The as-synthesized Pt–Au pNDs/RGOs exhibited significantly enhanced catalytic performance toward the reduction of 4-nitrophenol, as compared to commercial Pt black and home-made Au nanocrystals.

Facile synthesis of Pt–Pd nanodendrites and their superior electrocatalytic activity

In this report, well-dispersed porous Pt–Pd nanodendrites (Pt–Pd NDs) were synthesized at high yield by a simple, one-pot, wet chemical method without using any seed, template, or toxic organic solvent. Poly(vinylpyrrolidone) (PVP) and urea were employed as the co-stabilizing and co-structure-directing agents. It was found that the reaction temperature, the amount of PVP and urea, the Pt/Pd molar ratio, and the pH value of the reaction media greatly affected the size and shape of the Pt–Pd product. The as-prepared Pt–Pd nanocrystals had a larger active surface area, superior catalytic activity, and better stability for the electrooxidation of methanol and ethylene glycol (EG), compared with the commercial Pt-black and Pd-black catalysts.

One-pot synthesis of reduced graphene oxide supported hollow Ag@Pt core–shell nanospheres with enhanced electrocatalytic activity for ethylene glycol oxidation

In this study, a simple, facile and one-pot solvothermal method was developed for preparation of reduced graphene oxide (RGO) supported hollow Ag@Pt core–shell nanospheres (hAg@Pt), using ethylene glycol (EG) as a reducing agent and sodium dodecyl sulfate (SDS) as a soft template. Control experiments demonstrated that the molar ratios of the Pt–Ag precursors, the amount of SDS, the presence of RGO, and the reaction temperature were critical to the final nanocomposites. The as-prepared hAg@Pt–RGO showed the improved electrocatalytic activity and durability toward ethylene glycol oxidation, which can serve as a promising potential electrocatalyst in direct alcohol fuel cells.

Facile synthesis of ultrathin worm-like Au nanowires for highly active SERS substrates

In this report, ultrathin worm-like Au nanowires were constructed with the assistance of L-glutamic acid as a structure-directing agent and a weak stabilizing agent. The morphology of the Au products was found to be strongly dependent on the experimental parameters such as the amount of L-glutamic acid, as well as the reaction temperature. This synthesis was a seedless process, without using any template, surfactant, or toxic organic agent. Furthermore, the as-prepared Au nanowires were applied to facilely fabricate porous Au films with controllable thickness via simple gravity settling. The Au films showed high surface-enhanced Raman scattering (SERS) enhancement, using 4-mercaptobenzoic acid as a model probe. The Au films may be promising candidates for SERS sensing. This strategy provides an environmental friendly way for the preparation of various metal nanostructures with novel morphologies and useful applications.

Enhanced catalytic performance of Pd–Pt nanodendrites for ligand-free Suzuki cross-coupling reactions

Pd–Pt nanodendrites were synthesized by a facile, environment-friendly, one-pot wet-chemical method, without using any seed, template, or toxic organic solvent. The as-obtained bimetallic nanocrystals exhibited efficient catalytic activity toward ligand-free Suzuki cross-coupling reaction in ethanol aqueous solution. A series of biphenyl compounds were obtained with high yields under mild conditions. Furthermore, the catalyst could be easily recovered and reused at least 6 consecutive cycles, nearly without losing its catalytic activity.

Cu(II)@Luviset clear as recyclable catalyst for the formation of C–C bond in homo-coupling of terminal alkynes

Commercial copolymer Luviset clear (L1), an environmentally benign and efficient ligand, was used to facilitate the catalytic performance of Cu(NO3)2 for homo-coupling of terminal alkynes. A series of substituted aromatic and aliphatic terminal alkynes were investigated. It was found that Cu(NO3)2@L1 can catalyze the C–C coupling reactions without any other base, and the corresponding diynes are generated in good to excellent yield. X-ray photoelectron spectroscopy was used to study the reaction mechanism, and the results evidence a Cu(II)/Cu(I) catalytic system. Additionally, the catalyst can be easily separated and reused without showing significant loss of catalytic activity.

l-Arginine-assisted electrochemical fabrication of hierarchical gold dendrites with improved electrocatalytic activity

Shape and size control of gold (Au) nanocrystals plays important roles in their catalytic and optical properties. Hierarchical Au nanodendrites were directly electrodeposited on a glassy carbon electrode (GCE) using l-arginine as a growth-directing agent, while there is no seed, template, or surfactant involved. It was found that the experimental conditions such as the applied potentials, concentrations of HAuCl4 and l-arginine, and deposition time were essential to the final morphology of the Au deposits. The as-synthesized Au nanocrystals displayed enhanced electrocatalytic activity and improved stability for ethylene glycol (EG) oxidation in acidic media as compared to Au nanoparticles.

Bimetallic Au–Pd nanochain networks: facile synthesis and promising application in biaryl synthesis

A simple and facile method is described for the morphology-controlled synthesis of bimetallic Au–Pd alloyed nanochain networks (NNCs) that show high catalytic performance for the Ullmann intermolecular homocoupling of aromatic or alkyl halides (X = I, Br, Cl) in aqueous media and can be reused at least five times, which can also be applied to intramolecular homocoupling.