Synthesis of Metal Nanocomposite and Their Applications in Electroanaysis and Energy Conversion
Author:Liu Xiang Jian
Supervisor:zuo jian bo
The remarkable improvement in nanotechnology and nanoscience greatly contribute to the development of nanomaterials.Nanomaterials-based electrochemical signal amplifications have great potential of improving both sensitivity and selectivity for electrochemical sensors and biosensors.As is known to all,electrode materials are of vital importance for construction of high-performance electrochemical sensing platforms for detecting target molecules through various analytical principles.In addition,catalytic processes play a vital role in energy storage and conversion,while high efficient catalysts play a central role.Though the metal nanocomposites have been studied as a research frontier for many years,there are still a lot of problems remain to be solved.Noble metal based electrocatalysts possess excellent catalytic activity in many applications,which have been used as commercial catalyst in many cases.While they have disadvantages of the reserve scarce and high cost,exploiting non noble metal electroctalysts to substitute noble metal electrocatalyst is an interesting and challenging task.In this paper,we focused on the study of the synthesis and application of non-noble transition metal based nanocomposites in electrochemical sensor and energy storage and conversion.The effect of the architecture and composition of the catalyst toward their applications were carefully studied.Excellent performances were obtained in the work.The main points are outlined as follows:(1)Cu-based nanomaterials and their application in fabrication of non-enzymatic glucose sensor:Copper based nanomaterials have great potential in constructing of non-enzymatic glucose sensors.1)Wet chemical method was applied to synthesis of Cu nanorods with rough surface.There are CU2O formed in the rough structure on the surface,which can increase the amount of catalytic active sites and surface area.The as-prepared catalyst exhibited very low LOD,high sensitivity and excellent stability.2)Three dimensional Cu foam was applied as substrate to construct of self-supported electrode in alkaline solution via oxidation etching and subsequent annealing treatment.CuO nanoflower/nanowires were formed on the 3D skeleton.The resulting 3D self-supported sensing platform sensitively sensed the glucose in the alkline solution,which also showed low sensing LOD.3)We applied potentiostatic electrodeposition method fabricated coral-like Cu-based miro-/nano-arrays on the surface of copper foil in H2SO4 solution of CuSO4.Very low LOD,high sensitivity and stability were obtained when the self-supported platform employed in glucose sensing.(2)The synthesis of tri-metal phosphide and their application in oxygen evolution reaction and energy storage:Bimetal(Co,Ni)ZIF-67 were applied as template for the construction of porous ultrathin CoNiFe phosphide nanosheets assembled hollow spheres via a solvothermal process and subsequent low temperature phosphorization process.The resulting catalyst exhibited excellent electrocatalytic oxygen evolution reaction activity and good lithium storage performance.(3)Metal-carbon nanocomposites:The graphitic carbon nitrides and cobalt nitrate were applied as precursors,bamboo-like carbon nanotubes and carbon wrapped cobalt nanoparticles nanocomposites were obtained via a series of mechanical grinding,high temperature pyrolysis and acidic etching treatment.The as-prepared catalyst exhibited remarkable oxygen reduction reaction catalytic performance.