nitrophenols and gold-tetrachloride--acid

Long-term stable 3 nm gold nanoparticles are prepared by a simple reaction between HAuCl4 and sodium borohydride in water under ambient conditions which very efficiently catalyze 4-nitrophenol reduction to 4-nitroaniline.

Topics: Aniline Compounds; Borohydrides; Catalysis; Chlorides; Gold; Gold Compounds; Metal Nanoparticles; Molecular Structure; Nitrophenols; Particle Size

In this paper, we develop a cost-effective and simple route for the synthesis of Au nanoparticles (AuNPs) decorated graphene oxide (GO) nanosheets using polyoxyethylene sorbitol anhydride monolaurate (TWEEN 20) as a stabilizing agent for GO as well as a reducing and immobilizing agent for AuNPs. The AuNPs assemble on the surface of TWEEN-functionalized GO by the in situ reduction of HAuCl(4) aqueous solution. The morphologies of these composites were characterized by atomic force microscopy (AFM) and transmission electron microscopy (TEM). It is found that the resultant AuNPs decorated GO nanosheets (AuNPs/TWEEN/GO) exhibit remarkable catalytic performance for hydrazine oxidation. This hydrazine sensor has a fast amperometric response time of less than 3s. The linear range is estimated to be from 5 μM to 3 mM (r=0.999), and the detection limit is estimated to be 78 nM at a signal-to-noise ratio of 3. The AuNPs/TWEEN/GO composites also exhibit good catalytic activity toward 4-nitrophenol (4-NP) reduction and the GO supports also enhance the catalytic activity via a synergistic effect.

Topics: Catalysis; Chlorides; Gold; Gold Compounds; Graphite; Limit of Detection; Metal Nanoparticles; Microscopy, Atomic Force; Microscopy, Electron, Transmission; Nitrophenols; Oxidation-Reduction; Polysorbates; Spectrophotometry, Ultraviolet; Surface-Active Agents; Water