The Synthesis Of Nanostructured Transitional Metal Compounds And Their Application In Electrocatalysis

The modified electrodes based on nanomaterials are prepared and applied to thefood, environmental and biological electrochemistry,which is an organic combinationof nanotechnology and electroanalytical chemistry.It is a promising research fieldwhich is advantage to form the new technology and new method and accelerate thedevelopment of electrochemistry.Noble metals such as platinum, palladium, rhodium, iridium andgold are excellentoxidation catalysts. However, despite all the virtues such as stability and high activitythat the noblemetals have,considering cost evaluation, great endeavors have beenturned to the direction of transition metal oxide-based catalysts as an alternative. Themain work of this paper focuses on one of the most active field where nanotechnologycombines with electroanalytical chemistry,preparation and application of novelnanomaterial-modified electrodes.CuO nanochains modified electrode: A facile wet chemical method for thesynthesis of hierarchically nanostructured CuO chains assembled with small nanorodsis reported. The autocatalytic response to nitrite ions is also carried out, whichexhibits good analytical performance with a wide linear range（0.004–3.7mM）, withlow detection limit of3×104mM.MnOOH nanobelts modified electrode: MnOOH nanobelts were synthesized andused as the sensing material to fabricate a modified glassy carbon electrode（n-MnOOH electrode） for simultaneously detecting dopamine （DA） from ascorbicacid （AA） and uric acid （UA）. It was found that thethe n-MnOOH electrode exhibitedgood sensing performance for determination of dopamine with a linear range of2μM²00μM, detection limit of0.11μM and sensitivity of3.77μA·μM^-1·cm^-2. Highselectivity toward DA from ascorbic acid （AA） and uric acid （UA） at their maximumphysiological concentrations was also observed, which implies the promisingapplication for various bioelectrochemical sensors.Cu₄（OH）₆SO₄nanorods modified electrode: Cu₄（OH）₆SO₄nanorods weresynthesized via a facile solution route. A new electrochemical biosensor for cysteinedetermination was then proposed by using the Cu₄（OH）₆SO₄nanorods as the sensinglayer. Electrochemical tests showed that the Cu₄（OH）₆SO₄nanorods modifiedelectrode could act as efficient enzyme-like electron mediators for cysteine oxidation. The linear range between0.008to2.9mM, and the detection limit of2×10^-8mol/L.Nanostructured Fe₃O₄films electrode: hierarchically nanostructured magnetitefilms were first prepared by a facile wet chemical process. The resulted cuprite filmwas then characterized by Raman spectrum, scanning electron microscopy （SEM） andtransmission electron microscopy （TEM）. Electrochemical catalytic performance ofthe film was also tested The low detection limit was estimated to be2.0×10^-9M, andthe time required to reach95%of the steady-state current was shorter than8s afterthe addition of ascorbic acid, which demonstrated that the as deposited nanostructuredmagnetite film has both high catalytic sensitivity and fast current response in ascorbicacid sensing.