具表面電漿共振特性之雙金屬奈米材料合成及應用

Abstract

Since bimetallic nanomaterial was credited with far features beyond single metal nanomaterial and has shown much outstanding performances in such fields, energy, biosensors, imaging, it has attracted much attention in nanotechnology recently. The improvement of oxygen reduction reaction (ORR), the cathodic reaction in renewable energy technologies, such as fuel cells, metal-air batteries, and so forth, is of vital importance due to the increasing demands of energy by rising steeply population. The ORR commonly involves four-electron (4e-) transfer to produce water directly, whereas another parallel two-electron (2e-) pathway producing undesired and damaging peroxide species competes against the initial 4e- pathway. Based on above-mentioned conditions, we were about to develop the bimetallic nanomaterial with surface character of surface plasmon resonance to alter the ORR pathways toward 4e- pathway. Herein, we demonstrated the first empirical evidence of tunable two-/four-electron pathway toward ORR through plasmonic effects (up to 0.2 mA/cm2 enhancement in current density and 4% pathway alternation to 4e-), in which plasmonic Ag-Pt bimetallic nanocages were synthesized with an edgeless feature and a custom-made RDE/RRDE working station was designed to provide unique means by which to realize the plasmonic effects toward the target oxygen reduction reaction. The edgeless Ag-Pt bimetallic nanocages with hollow interior performed newly plasmonic induced effects to alter the reaction pathway of ORR, where the formation of undesired peroxide intermediate was significantly suppressed since the hot electron transfer of Ag nanostructure offered sufficient energy to populate the antibonding orbital of O2. This rapid light-dependent nature corresponding to localized surface plasmon resonance can potentially offer synergetic strategies toward altering the chemical reactions or reaction pathways in various fields.