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Application Research Of Novel 2D Nanomaterials In Electrochemical Sensors And Oxygen Evolution Reaction

Posted on:2022-11-04Degree:MasterType:Thesis
Country:ChinaCandidate:M YangFull Text:PDF
GTID:2481306785958489Subject:Light Industry, Handicraft Industry
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Compared with other nanomaterials such as dendritic macromolecules and one-dimensional rods,2D nanomaterials show unique advantages,namely good chemical,physical and biological properties,such as large specific surface area,good biocompatibility,excellent electron transfer ability and easy surface modification,which provide ideal performance for electrochemical sensing and electrocatalysis.In this paper,three novel 2D nanomaterials,including monolayer titanium carbide Ti3C2Tx-MXene,porous Co3O4nanodisks with nanozyme property and Ni Mo0.3/Fe0.2nanosheets with superior electrocatalytic oxygen evolution properties,were applied to construct electrochemical sensor and aptasensors for the detection of neurotransmitter serotonin(5-HT),common food mytoxins aflatoxin(AFB1)and ochratoxin(OTA)and electrocatalytic oxygen evolution reaction(OER)under alkaline condition,respectively.The results obtained were satisfactory.The main research work are as follows:1.The electrochemical sensor based on the nanocomposite of gold nanoparticle-doped Ti3C2Tx-MXene and multi-walled carbon nanotubes(Au NPs@Ti3C2Tx/MWCNTs)exhibits a good electrochemical response to 5-HT.One-dimensional MWCNTs can effectively prevent the stacking of Ti3C2Txand increase the conduction rate.On the other hand,noble metal Au NPs also play an important role in stabilizing the oxidation of Ti3C2Tx.After optimizing the experimental conditions,the linear range of determination of 5-HT is from 0.1 to 120?mol/L,and the detection limit was 30 nmol/L(at 3?).The sensor has good stability,repeatability and anti-interference ability.It can be applied to the determination of5-HT in human serum.2.A novel electrochemical aptasensor based on gold nanoparticles-loaded Ti3C2Tx-MXene composite nanomaterials(Au NPs@Ti3C2Tx)was prepared for sensitive detection of aflatoxin B1(AFB1).Taking advantage of the special two-dimensional structure of Ti3C2Txand its own reducibility,Au NPs were grown in situ on its surface simply,quickly and efficiently.The synthesized materials have excellent electrical conductivity,large specific surface area and good electrocatalytic activity,and can be used as substrate materials for electrochemical biosensors.Under the optimal experimental conditions,the detection limit of the AFB1 sensor for was6.3 pg/m L(at 3?),and the linear range was 0.05 ng/m L?100 ng/m L.The sensor has good specificity and repeatability.Otherwise,the experimental method is simple and effective.It has been applied to the determination of AFB1 in millet samples and has great potential in other food matrices.3.It has great potential in the detection of trace analytes that nanozymes are introduced into electrochemical aptasensing system.Co3O4has good nano-mimetic properties to catalyze the reduction of H2O2.DNA walkers which was driven by the nuclease Nb.Bbv CI and target,cascading with porous Co3O4nanodiscs was used to construct electrochemical aptasensor,which can selectively detect the ochratoxin A(OTA).The dual signal amplification device based on nuclease-driven DNA walker and Co3O4nanozyme can effectively improve the detection sensitivity.The sensor has a good linear relationship in the range of 1 pg/m L?100 ng/m L,the detection limit is0.194 pg/m L(at 3?),and detection effect is comparable to the standard ELISA method in real samples.It also has good reproducibility and specificity.This sensing strategy provides a feasible way for the detection of other targets.4.Electrocatalytic water splitting to produce oxygen and hydrogen is a green technology.The development of low-cost,high-efficiency oxygen evolution reaction catalysts is the key to controlling water splitting efficiency and developing sustainable hydrogen energy.The development of non-noble metal water electrolysis catalyst is expected to achieve efficient water electrolysis hydrogen production.The composition,structure and microstructure of non-precious metal catalysts are all key factors affecting the performance of catalysts.In this paper,a Fe-doped ternary transition metal catalyst material was developed by means of one-pot hydrothermal synthesis of nickel molybdenum layered double hydroxide(Ni Mo LDH)as precursor.By adjusting the content and ratio of doped metal Mo and Fe,when Ni:Mo:Fe=1:0.3:0.2,the high-performance Fe0.2-Ni Mo0.3OER catalyst was successfully prepared.At current densities of 10 m A/cm~2and 50 m A/cm~2,OER overpotential is276 m V and 350 m V,respectively,and Tafel slope is 40.8 m V/Dec.It still has good stability at high current density(50 m A/cm~2).The strong electron interaction between Fe-Ni Mo can effectively promote the charge transfer rate of the reaction and improve the catalytic performance of OER.
Keywords/Search Tags:Ti3C2Tx-MXene, electrochemical sensing, nanozyme, Ni-based catalyst, oxygen evolution reaction
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