Controllable Preparation Of One-dimensional Organic-inorganic Nanomaterials And Their Reduction/Electrochemistry/Oxidation Properties

?-Ni(OH)₂ has shown potential applications in the catalytic reduction of 4-nitrophenol(4-NP)due to its facile,environmentally friendly and low cost preparation process.On the other hand,polyaniline is considered to be one of the most promising supercapacitor materials because of its reversible doping and desorption,simple preparation and redox reversibility.And solid acids have been widely used in the catalytic oxidation of olefin,which can be recycled repeatedly.Based on the unclear reason for the different catalytic reduction activity of?-Ni(OH)₂,the poor cycling stability of PANI based supercapacitor and the low catalytic efficiency of solid acid catalyzed olefin oxidation,it is proposed in the dissertation to prepare etched halloysite nanotube supported?-Ni(OH)₂and PANI/TiO₂in-situ,and study their 4-NP catalytic reduction and electrochemical capacitance properties.In addition,sulfonated poly(divinyl benzene)bamboo-like nanotubes is synthesized by in combination of cationic polymerization and sulfonation modification,and its catalytic oxidation properties of cyclohexene are further studied.The main conclusions are as follows:1.A series of etched halloysite nanotubes(e HA)supported?-Ni(OH)₂ are synthesized via a one-pot facile co-precipitation method.By expediently controlling the variety of alkali source,etched halloysite nanotubes@?-Ni(OH)₂(e HA@?-Ni(OH)₂)with different different specific surface areas,?-Ni(OH)₂ morphology and Ni²⁺ions content can be achieved.The prepared?-Ni(OH)₂@e HA is used to catalytically reduce 4-nitrophenol(4-NP).It shows?-Ni(OH)₂@e HA prepared with n-butylamine as alkali source(?-Ni(OH)₂@e HA-B)exhibits enhanced 4-NP catalytic activity(k_app=1.458×10^-2 s^-1,K=583.27 s^-1·g^-1).The catalytic reduction property is in accordance with the Ni²⁺ions content of?-Ni(OH)₂@e HA.Moreover,it also exhibits good cycle stability due to the synergy of the support-e HA and the supported Ni²⁺ions in?-Ni(OH)₂,which can achieve 99%4-nitrophenol conversion after 11 cycles.Ni²⁺ion reduction experiment illustrates that Ni²⁺ion is the activation site and the enhanced 4-NP reduction activity of?-Ni(OH)₂@e HA-B is attributed to the higher Ni²⁺ion content,which accelerates the electron transport from Na BH₄ to 4-NP to result in the catalytic reduction of 4-NP to 4-aminophenol(4-AP).2.e HA/PANI/TiO₂ composite nanorods are achieved by low temperature induced growth of polyaniline and crystalline TiO₂ on etched halloysite nanotubes in-situ simultaneously.By adjusting the volume ratio of aniline/titanium isopropoxide(ANI/TTIP)in the preparation process,the supported PANI content can be adjusted.Furthermore,the doping degree/redox state of PANI and TiO₂ crystal form can be tuned by the acidity of the reaction system.Electrochemical properties of a series of e HA/PANI/TiO₂ composite nanorods are studied by cyclic voltammetry and constant current charge-discharge methods.It exhibits e HA/PANI/TiO₂nanotubes prepared with 100%volume ratio of ANI/TTIP,p H at 0.5 and HCl as dopant acid(e HPT-0.5-100%-HCl)demonstrates the highest specific capacitance(456.93 F·g^-1).3.Sulfonated poly(divinyl benzene)(SPDVB)bamboo-like nanotubes is synthesized by in combination of cationic polymerization and sulfonation modification.By controlling the sulfonation time,a series of SPDVB materials with different sulfonation degrees can be prepared.The catalytic oxidation performance of SPDVB bamboo-like nanotubes for cyclohexene is further investigated.It is found that solvents,catalysts(including sulfonation time and amount),oxidants(including type and amount),reaction temperature,reaction time and catalytic system have an effect on the catalytic oxidation performance of SPDVB bamboo-like nanotubes for cyclohexene.Among them,the reaction system shows optimal catalytic activity(97.22%conversion and 93.74%1,2-cyclohexanediol selectivity)when cyclohexene oxidation is conducted under the following conditions:solvent-free,10 mg SPDVB-24h,1.25m L hydrogen peroxide,0.6 m L cyclohexene,75?reaction temperature,24 h reaction time and pickering emulsion catalytic system.Recycle stability experiments show that 98.02%of the initial conversion rate is still maintained after 4 cycles;cyclohexene conversion and 1,2-cyclohexanediol selectivity are respectively 95.27%and 97.38%.A possible mechanism for the oxidation of cyclohexene to 1,2-cyclohexanediol by sulfonated polydivinylbenzene bamboo-like nanotubes is proposed:the-SO₃H group of sulfonated poly(divinyl benzene)bamboo-like nanotubes is converted to peroxysulfonic acids(catalytic activity center)under hydrogen peroxide firstly;then the formed peroxysulfonic acid attacks the double bond of cyclohexene to form epoxy cyclohexane intermediates,which will be rapidly hydrolyzed to 1,2-cyclohexanediol.