Multicomponent nanoparticles (NPs) with at least two different components in one nanostructure have attracted great interest due to the multifunctionalities and enhanced properties they exhibit. By using a seed-mediated growth method, I have successfully synthesized various core/shell and dumbbell-like NPs and studied their potential applications in catalysis, biological detection and nanomagnetism. <br/> Platinum (Pt) has been explored as a superior catalyst towards many reactions including oxygen reduction reaction and methanol oxidation reaction. However, Pt catalysts are limited as a practical fuel cell catalyst due to its high cost and poor stability. In the first part of my thesis, I aim to develop a new class of core/shell NPs of Au/MPt (M=Fe, Co, Mn, Cu) with tunable core/shell dimension for enhanced fuel cell catalysis. I demonstrated that these core/shell NPs were excellent catalysts for oxygen reduction reaction and methanol oxidation reaction with much improved catalytic activity and stability.<br/> Real time detection of H2O2 from live cells can provide an effective way to understand cellular functions and pathology. In this part of my thesis, I demonstrated that dumbbell-like PtPd-Fe3O4 NPs were a robust probe for H2O2 sensing and detection. Dumbbell-like PtxPd100-x-Fe3O4 NPs were synthesized by controlled nucleation and growth of Fe over PtxPd100-x NPs followed by air oxidation. These NPs show the Pt, Pd composition dependent catalysis for H2O2 reduction. Among different dumbbell NPs tested, Pt48Pd52-Fe3O4 NPs were the most active with a detection limit reaching 5 nM. My further studies show that Pt48Pd54- Fe3O4 NPs could be made biocompatible and be combined with 3,3',5,5'-tetramethylbenzidine (TMB) for H2O2 detection in biological solutions. The Pt48Pd54- Fe3O4/TMB kit was successfully used to quantitatively monitor extracellular H2O2 generated by neutrophils. <br/> My thesis work also includes the synthesis of core/shell Au/MPd (M= Fe, Cu, Pd) NPs for catalytic applications and FeO/Fe3O4 NPs for magnetic studies.<br/>
Sun, Xiaolian,
"Synthesis and Applications of Multicomponent Nanoparticles"
(2012).
Chemistry Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0GF0RTR
