Based On Cu-BTC Metal Organic Framework Material Photo/electrochemical Sensor Construction And Organophosphorus Pesticide Detection Research

Metal-Organic Frameworks(MOFs)refer to crystalline materials with periodic network structures formed by organic ligands and metal ions or metal clusters through self-assembly process.Due to the controllability of their pore structures and large specific surface area,MOFs have broad application prospects,such as gas storage,adsorption and separation,catalysts,sensors,energy materials and so on.Recently,the study proves that MOFs have novel and interesting applications in sensing of small solvent and gas molecules,as well as excellent performance in pesticides detection.The unique properties of MOFs make it be a kind of ideal candidate for sensing applications.In this thesis,a photo/electrochemical sensor was constructed based on MOFs.According to their large specific surface area and hierarchically properties,the detection of non-electroactive pesticides such as glyphosate and malathion was studied.The main research contents can be divided into the following sections:(1)An electrochemical sensor based on hierarchically Cu-BTC MOF material for non-electroactive glyphosate detection has been firstly constructed in this report.By using Cu-BTC frameworks as detection matrix,the large specific surface area of the material can increase the electrode reaction site and further improve the detection performance and sensitivity.Under optimum conditions,differential pulse stripping voltammetry(DPV)was employed to detect glyphosate.The results show that the fabricated sensor displays ultralow detection limit(1.4×10-13 mol L-1)and wide linear range(1.0×10-12?1.0×10-9 mol L-1 and 1.0×10-9?1.0×10-5 mol L-1).Besides,this sensor possesses acceptable reproducibility and stability,as well as good selectivity.It is worth mentioning that this effectively Cu-BTC based sensor has great potential application in sensitive and selective detection of organophosphorus pesticides in actual samples.(2)A photoelectrochemical sensor based on Cu-BTC/CN-NS material was constructed for the first time.Cu-BTC can effectively improve the photocurrent conversion efficiency of CN-NS.Under visible light irradiation,the formation of Cu-glyphosate complexes on Cu-BTC nanoparticles with the addition of glyphosate leads to the increased steric hindrance of electron transfer from the Cu-BTC nanoparticles to the electrode surface,and consequently resulted in an obvious decrease in photocurrent.The experimental results show that the photoelectrochemical sensor has a lower detection limit of 1.3×10-13 mol L-1 and a wide linear range(1.0×10-12?1.0×10-8 mol L-1 and 1.0×10-8?1.0×10-3 mol L-1).In addition,the method has the characteristics of zero potential,short detection time,and easy operation.(3)A photoelectrochemical sensor based on hierarchically Cu-BTC derived CuO material was constructed.The CuO obtained by calcining Cu-BTC at a high temperature substantially inherits the morphology and size of the precursor Cu-BTC,and has a high photocurrent conversion efficiency.Under the irradiation of visible light,with the addition of malathion,the formation of CuO-malathion complex on the CuO gave rise to an increase in steric hindrance,and consequently resulted in an obvious decrease in photocurrent.The experimental results show that the photoelectrochemical sensor has a lower detection limit of 2.8×10-13 mol L-1 and a wide linear range(1.0×10-12?1.0×10-10 mol L-1 and 1.0×10-10?1.0×10-5 mol L-1).Achieve the sensitive detection of non-electroactive organophosphorus based on MOFs derived sensors.