Facile synthesis of 2D silver nanocrystals by a gas–solution interface technique

Interface-Assisted Synthesis of the Mn3-xFexO4 Gradient Film with Multifunctional Properties

Anisotropic gradient materials are considered as promising and novel in that they have numerous functional properties and are able to transform into hierarchical microstructures. We report a facile method of gradient inorganic thin film synthesis through diffusion-controlled deposition at the gas-solution interface. To investigate the reaction of interfacial phase boundary controllable hydrolysis by gaseous ammonium, an aqueous solution of FeCl₃ and MnCl₂ was chosen, as the precipitation pH values for the hydroxides of these metals differ gradually. As a result of synthesis using the gas-solution interface technique (GSIT), a thin film is formed on the surface of the solution that consists of Mn²⁺(Fe,Mn)₂³⁺O₄ nanoparticles with hausmannite crystal structure. The ratio between iron and manganese in the film can be adjusted over a wide range by varying the synthetic procedure. Specific conditions are determined that allow the formation of a Mn-Fe mixed oxide film with a gradient of composition, morphology, and properties, as well as its further transformation into microscrolls with a diameter of 10-20 μm and a length of up to 300 μm, showing weak superparamagnetic properties. The technique reported provides a new interfacial route for the development of functional gradient materials with tubular morphology.

Facile synthesis of scandium fluoride oriented single-crystalline rods and urchin-like structures by a gas–solution interface technique

ScF₃ rod-like oriented crystals and urchin-like structures were synthesized at the gas–solution interface for the first time.