Li-Xian Chen

Theophylline-assisted, eco-friendly synthesis of PtAu nanospheres at reduced graphene oxide with enhanced catalytic activity towards Cr(VI) reduction

Theophylline as a naturally alkaloid is commonly employed to treat asthma and chronic obstructive pulmonary disorder. Herein, a facile theophylline-assisted green approach was firstly developed for synthesis of PtAu nanospheres/reduced graphene oxide (PtAu NSs/rGO), without any surfactant, polymer, or seed involved. The obtained nanocomposites were applied for the catalytic reduction and removal of highly toxic chromium (VI) using formic acid as a model reductant at 50°C, showing the significantly enhanced catalytic activity and improved recyclability when compared with commercial Pt/C (50%) and home-made Au nanocrystals supported rGO (Au NCs/rGO). It demonstrates great potential applications of the catalyst in wastewater treatment and environmental protection. The eco-friendly route provides a new platform to fabricate other catalysts with enhanced catalytic activity.

Ionic liquid-assisted synthesis of composition-tunable cross-linked AgPt aerogels with enhanced electrocatalysis

A facile one-pot coreduction strategy was developed to synthesize composition-tunable cross-linked AgPt aerogels, where ionic liquid (1-aminopropyl-3-methylimidazolium bromide, [APMIm]Br) played a significant role in controlling the morphology and structure. During the synthesis progress, Br- easily reacted with Ag+ to form AgBr precipitate and consequently slowed down the reducing rate of Ag+, as well as acting as a capping agent to promote the anisotropic growth of AgPt aerogels, as mainly demonstrated by the electronic microscopy, Brunauer-Emmett-Teller, X-ray diffraction and X-ray photoelectron spectroscopy analysis. The architectures showed superior catalytic activity and enhanced durability toward ethanol oxidation reaction (EOR) and ethylene glycol oxidation reaction (EGOR) in contrast with commercial Pt black, owing to the tailored composition, morphology and electronic structure of the prepared AgPt aerogels.

One-pot controlled synthesis of AuPd@Pd core-shell nanocrystals with enhanced electrocatalytic performances for formic acid oxidation and glycerol oxidation

In this work, AuPd@Pd core-shell nanocrystals (AuPd@Pd NCs) were fabricated by a one-pot co-reduction approach, where theophylline-7-acetic acid (TAA) acted asa new structure-directing agent. The crystal structure and composition were mainly characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), X-ray diffraction (XRD), together with X-ray photoelectron spectroscopy (XPS). The growth mechanism of AuPd@Pd NCs was investigated in detail. The obtained AuPd@Pd NCs exhibited superior catalytic characters for formic acid oxidation reaction (FAOR) and glycerol oxidation reaction (GOR) in contrast with commercial Pd black in alkaline media.