One-pot synthesis of Fe3O4 nanoprisms with controlled electrochemical properties

Abstract

Fe(3)O(4) nanoprisms, synthesized by a solvothermal process, exhibited crystal plane dependent electrochemical activities, which opens an approach to nanoscale materials with controlled electrochemical properties.

Dependence of the size of nanoparticles of lead sulfide PbS on the chemical affinity of its formation reaction

“…As a result, the hydrolysis of the precipitant (NH 2 ) 2 CS leads not so much to the emergence of new PbS crys tallization nuclei as to an increase in the size of the already forming nuclei. The nuclei growth rate is directly proportional to the initial concentrations of Pb(СН 3 COO) 2 and N 2 H 4 CS, i.e., to А.…”

“…Initially, the reaction of Pb(СН 3 COO) 2 with Na 3 C 6 H 5 O 7 gave the complex lead salt Pb(OH)Cit 2-, and the further precipitation occurred by the reaction (2) To calculate А by formula (1) at the initial moment of the process, it is necessary to make a thermody namic analysis of the initial conditions. Taking into account the reversibility of the hydrolytic decomposi tion of (NH 2 ) 2 CS in aqueous alkaline solutions [6], we performed a thermodynamic analysis of the equilib rium existence of lead sulfide, lead hydroxide, and other intermediate products of the precipitation reac tion as shown previously [9,10].…”

“…Based on the calcula tion results, we made a well founded choice of the pH range and the concentrations of the components of the system Pb In the heterogeneous method of chemical precipi tation, PbS was synthesized [11] by mixing stoichio metric amounts of aqueous solutions of lead acetate and sodium sulfide by the reaction Pb(СН 3 COO) 2 + Na 2 S = PbS + 2NaСН 3 COO. (3) In the interaction of the aqueous solutions of Pb(СН 3 СОO) 2 Because the chemical precipitation of PbS was per formed at different concentrations of the initial com ponents, the А value was varied over a wide range. The chemical precipitation of PbS was carried out at con stant temperature and pH, and also at the same sequence and rate of mixing of reactants.…”

“…An alternative to organo metallic synthesis is an experimentally simpler synthe sis method called one pot method. This method is currently widely used in organic synthesis but is becoming more and more popular for synthesizing inorganic compounds in the nanocrystalline state, e.g., oxides [2], core@shell structures based on pure metals [3] and metal chalcogenides [4], and semicon ductor nanocrystals and quantum dots [5]. Among one pot methods is chemical condensation or chemi cal precipitation from solutions, by which nanoparti cles can be synthesized directly in the aqueous medium-this is a necessary condition of using these nanoparticles in biology and medicine.…”

Fabrication of magnetic nanorods and their applications in medicine

“…In this context, Sun and colleagues worked on single-dispersive Fe 3 O 4 and MFe 2 O 4 nanocrystals [26]. Zeng et al [27] synthesis Fe 3 O 4 nanorods by hydrothermal method with using surfactants and oleylamine reducing agent. The nanorods were grown in the (111) and (220) crystalline plates.…”