Silver Ammonia Solution Research Articles

UV photolysis-induced generation of graphene/M (M=Ag/Au) hybrid nanomaterials

The reduction of graphene oxide (GO) can be induced by the photolysis of silver or gold ions under UV light, resulting in the formation of G/M (M=Ag/Au) hybrid nanomaterials. This one-pot reduction method was performed using GO aqueous solution and silver ammonia solution or chloroauric acid solution under UV light. No additional chemical reductant was involved during the synthetic process. The existence of Ag nanoparticles on the surface of graphene nanosheets and the reduction of GO were characterized by XRD, TEM, SAED, FTIR and XPS. The obtained hybrid nanomaterial exhibits SERS activity and thus has a potential application as SERS substrate.

Micro-nanoscale binary structured silver films fabricated by electrochemical deposition

Silver nanoparticles have been grown by electrolysis of a silver ammonia solution in the presence of a small amount of aluminium nitrate. The Ag particles were found to exist in several shapes ranging from spherical, rod and sheet-like depending upon the conditions used for electrosynthesis. Films composed of these nanoparticles have micro-nanoscale binary structures. After passivation with n-dodecanethiol, these surfaces showed super-hydrophobic property with contact angles around 150° and sliding angles less than 5°.

Silver Nanocubes Formed on ATP-Mediated Nafion Film and a Visual Method for Formaldehyde

The ability to construct size- and shape-controllable architectures is essential for the exploration of nanoparticle-structured properties, and it is a good strategy of employing metal nanoparticles embedded in a polymer matrix in order to prepare new materials with particular properties. Herein, we found that adenosine-5'-triphosphate (ATP) could be applied to adjust and control the formation of silver nanocubes (Ag-NCs) on Nafion film. Nafion could be saturated with [Ag(NH3)2]+ when incubated in silver ammonia solution, and it was found that the Nafion film saturated with [Ag(NH3)2]+ becomes yellow after immerged in a mixture containing NaOH, ATP, and formaldehyde, resulting in monodisperse Ag-NCs on the film. Thus, ATP as a molecular mediator and Nafion film as a polymer matrix are employed toward the preparation of size-controllable and monodisperse Ag-NCs, and a novel visual method for formaldehyde is further developed on the basis of the color change of the Nafion film, which gives sensitive detection of formaldehyde with a limit of determination of 60 ppb (3sigma).

Indirect complexometric determination of small amounts of tellurium

A complexometric method is proposed for the determination of small amounts of tellurium (50–350μg). It is based on the reaction between Te(IV) and diethyldithiocarbamic acid (DDTC). The compound of the composition Te(DDTC)4 obtained is extracted with CCl4 at pH 8.7–8.8. The yellow organic extract is shaken with copper(II)-ammonia solution, ph 11. The organic phase, containing Cu(DDTC)2 is then shaken with silver-ammonia solution. The Cu(II)-ions pass into the aqueous phase where they are titrated with 0.002M EDTA, using glycinethymol blue as indicator. Selenium(IV) does not interfere.