Research On Electrocatalytic Properties And Self-assembly Behavior Of Exfoliated Layered Nanosheets And Metalloporphyrin

Owing to the unique structural properties of inorganic layered materials, functional guest molecules can be introduced into the interlayer of the host material by several intercalation techniques without damaging the basic layered structure, and the obtained hybrids possess high stability. Nanocomposites obtained through intercalation reaction are equipped with excellent proformance of the host layer and the guest molecules, and they have a number of potential applications in the fields of electrochemical and biological sensors, optics, catalytic materials adsorptive/separation and nano-devices, etc.Cationic layered compounds(α-Zr P, KLa Nb2O7) and anionic layered compounds(Cu2(OH)3NO3, Zn5(OH)8(NO3)2·2H2O, Co-Al LDHs) are chosen as the host laminate, and ammonium metalloporphyrin compounds(Mn TMPy P, Fe TMPy P, Co TMPy P) and sulfonate metalloporphyrin compounds(Mn TSPP) are chosen as the guest molecules, eight kinds of novel inorganic-organic composite materials are obtained, and their electrochemical properties are investigated. The main research contents are in the following:1. The host materials of α-Zr P and KLa Nb2O7 are prepared adopting a slightly modified HF approach and high temperature solid-state method respectively, then the exfoliation/restacking method is used to obtain α-Zr P and La Nb2O7- nanosheets(α-Zr P host material and the acidified product, KLa Nb2O7, are dispersed in a certain volume of TBAOH aqueous solution), and the existence of the nanosheets is confirmed by zeta potential and TEM, at last, five kinds of laminar composite materials are obtained through the self-assembly between the nanosheets obtained above and ammonium metalloporphyrin compounds(Mn TMPy P 、 Fe TMPy P 、 Co TMPy P), and the final products are analyzed by several characterization methods, such as XRD, IR, UV-vis, SEM, TG-DTA, and so on.2. The host materials of Cu2(OH)3NO3, Zn5(OH)8(NO3)2·2H2O and Co-Al-CO3 LDHs are prepared through a gradual dropwise addition method using a constant pressure funnel and urea hydrolysis method, then the obtained products of Cu2(OH)3NO3, Zn5(OH)8(NO3)2·2H2O and Co-Al-NO3 LDHs(the ion-exchange product of Co-Al-CO3 LDHs) are dispersed in formamide solvent under nitrogen atmosphere, thus obtained Cu2(OH)3NO3, Zn5(OH)8(NO3)2·2H2O and Co-Al LDHs nanosheets that are identified by zeta potential and AFM, finally, two kinds of laminar composite materials are obtained through the self-assembly between the nanosheets obtained above and sulfonate metalloporphyrin compounds(Mn TSPP), and the final products are characterized by XRD, IR, UV-vis, SEM.3. Cyclic voltammetry(CV) and differerntial pulse voltammetry(DPV) are applied for measuring the electrochemical performance of Mn TMPy P-α-Zr P/GCE, Co TMPy P-α-Zr P/GCE, Mn TMPy P-La Nb2O7/GCE, Fe TMPy P-La Nb2O7/GCE and Co TMPy P-La Nb2O7/GCE hybrid film in netural phosphate buffered solution adopting a conventional three-electrode system, the results indicated that the above-mentioned modified electrode exhibited catalytic activity toward O2, Na NO2, AA, and N2H4·H2O to some extent.4. The electrochemical property of Mn TSPP-Cu2(OH)3NO3/GCE, Mn TSPP-Zn5(OH)8(NO3)2·2H2O/GCE and Mn TSPP/Co-Al LDHs hybrid film are investigated by the same electrochemical method mentioned above in netural phosphate buffered solution, the results suggested that functional metalloporphyrin molecules(Mn TSPP) in Mn TSPP-Zn5(OH)8(NO3)2·2H2O/GCE and Mn TSPP/Co-Al LDHs hybrid film showed superior electron transfer property.