Solid State Morphology and Size Tuning of Nanostructured Platinum Using Macromolecular Complexes

Abstract

The macromolecular complexes Chitosan•(PtCl 2 ) n and PSP-co-4-PVP•(PtCl 2 ) n , were prepared from the respective polymer and PtCl 2 in metal:polymer molar ratios 1:1 and 1:5. Pyrolisis of the macromolecular complexes Chitosan•(PtCl 2 ) n and PSP-co-4-PVP•(PtCl 2 ) n at 800 °C under air affords cubic nanostructured Pt in the pure phase. The morphology of the pyrolityc products depends on the molar metal:polymer ratio; i.e. a "cotton" 3D shape for the 1:1 ratio and a "foamy" 3D shape for the 1:5 ratio. On the other hand, the particle size depends on the polymer nature, obtaining Pt nanoparticles as small as 6 nm for the chitosan precursors in both molar ratio.

Solid-state synthesis of LnOCl/Ln2O3 (Ln = Eu, Nd) by using chitosan and PS-co-P4VP as polymeric supports

“…Similarly to LnOCl materials, the synthesis of Ln 2 O 3 is usually achieved by using solution methods [17,18] , being the solid-state routes limited to a solution-solid state route based on a coordination polymer created by the combination of a lanthanide metal and amino acids [8] . Our group has been recently studying different solid-sate routes to nanostructured metal oxides such as V 2 O 5 [19] , Fe 2 O 3 [20] , ZnO [21] , SnO 2 [21] as well some metal as Pt [22] and mixtures as Pd/PdO [23] . These solid-state routes are based on heating an appropriate macromolecular complex, which has been previously created by mixing a polymeric support and metallic salt.…”

Incorporation of Au and Ag Nanostructures Inside Sio2

“…The macromolecular complexes (PS-co-4-PVP)•(AuCl3)n and (Chitosan•(AuCl3)n prepared as previously described (see experimental part and ref. [22][23][24][25][26].and the SiO2 (prepared by sol-gel method see experiemental part and ref. 27,28) were mixture in solid state in a crucible and pyrolyzed under air at 800 °C.…”

“…In a typical synthesis [22][23][24][25][26] , the respective metallic salts AuCl3 and Ag(NO3) were added in a Schlenk tube using CH2Cl2 as solvent under magnetic stirring and then the respective Chitosan amount was added according to the 1:1 (1),(5) or 1:5 (2), (6) respectively for Au and Ag molar ratio (compound numeration according Table 1). Table 1.…”

“…Previously we have reported a versatile and reliable solid-state method to prepare metallic and metal oxides nanostructures materials [22][23][24][25][26] and their incorporation in SiO2 matrices 27,28 . The method consists in the pyrolysis of the macromolecular precursors (Chitosan)•(MLn)n•(SiO2)m and (PS-co-4-PVP)•(MLn)n•(SiO2)m where the precursors (Chitosan)•(MLn)m and (PS-co-4-PVP)•(MLn)m are generated according previous reports [22][23][24][25][26] .Now, we use this approach to prepare Au° and Ag° inside SiO2 to give Au/SiO2 and Ag/SiO2 composites founding that the dispersion of the metal noble nanoparticles into the silica matrix can be controlled by the 1:1 or 1:5 metal/polymer ratio, as well as, by the nature of the polymer. The results are compared with those previously obtained 27 for bimetallic composites Au/Ag//SiO2.…”

OXIDATION FACILITY BY A TEMPERATURE DEPENDENCE ON THE METAL NOBLE NANOSTRUCTURED M°/MxOy PHASE PRODUCTS USING A SOLID STATE METHOD: THE CASE OF Pd

“…Macromolecular precursors were prepared according previous works [25,26]. In a typical synthesis the respective metallic salt PdCl 2 was added in a Schlenk tube over the CH 2 Cl 2 (50 mL) under magnetic stirring and then the respective polymer PSP-co-4-PVP and Chitosan amountwas added, according the 1:1 and 1:5 or 1:10 molar ratio for 15 days at room temperature.…”