Synthesis, Characterization Of Nanoparticles In Organic Phase And The Research Of Electrochemistry Properties

With the rapid development of science and technology in recent years, thedemands of energy for humans increases heavily. Nanomaterials, especially foroptics, electrical, and catalytic applications, have attracted much attentions.Nanoparticles (NPs) with their sprcific quantum confinement effect and size effecthave been applied in many fileds, such as photovoltaic devices, fuel cell, andsupercapacitor devices. The constituents, together with their constructions are thekey factor for their performance of devices. To further optimize the performanceand structure of device, synthesis techniques of NPs are promoted and developed.NPs with various constituents, morphologies, and constructions are synthesizedsuccessfully. Accordingly, great progress has been achieved to design the low costmethods with simple and friendly approach, in order to realize the evolution ofproperties. In this paper, we studied the electrochemical properties of NPs, andinvestigated the relationships between electrochemical characters and structures ofNPs, to promote the further applications in the fields of photo-electrochemistry.In the second chapter, CoPt3NPs with controlled shapes and facets weresynthesized via a non-injection strategy. By using benzyl ether as anon-coordination solvent and adjusting the OLA-to-OA ratio, spherical particleswith irregular facets,(100)-facet-dominant nanocubes, and (111)-facet-dominantnanoflowers were synthesized. A comparison of the electrocatalytic activitiesrevealed that the flowerlike CoPt3NPs were more active for the catalytic oxidationof methanol, because the (111)-facet-dominant CoPt3facilitated CO removal. Our finding demonstrated that in the case of high active fuel cell catalysts,(111)-facet-dominant CoPt3NCs were better candidates.In the third chapter, small CoS NCs are synthesized in high-boilingpointsolvent of benzyl ether through the thermolysis of Co and S precursors. The usingof OLA and OA as the co-ligands permits to produce solution-processed capacitormaterials with controlled size. The small size of CoS NCs leads to high SSA for theFaradaic energy storage. The pseudocapacitance activity is revealed bygalvanostatic charge-discharge measurement, which exhibits a high capacitance of790F g-1.The high capacitance and solutionprocessed property make the CoS NCsas competitive supercapacitor materials both for performance enhancement anddevice construction. In addition, the demonstrated relation between NC size andcapacitance make the current effort extendable to diversified capacitor materials bysynthesizing small and solution dispersible NCs.In the fourth chapter, Au-CuZnSe2heterostructured nanosheets aresynthesized by means of one-pot colloidal chemistry route. The compatibility ofhexagonal CuSe lattice with fcc Au, and cubic ZnSe greatly facilitates theAu-induced heterogeneous nucleation and growth of semiconductor domains.Resulting from the unique electronic structure, the Au-CuZnSe2heterostructurednanosheets exhibit better electrochemical activity than heterostructured nanorods,separate Au, and CuZnSe2, which makes such heterostructured2D nanomaterialsas competitive catalysts in electrochemical applications. And the kinetics studyreveals a four-electron procedure for the oxygen reduction reaction with anexcellent electrochemical stability.