| Cellulose nanocrystals(CNCs)can improve the chemical resistance of cellulose,low strength,and can be used as a natural and non-polluting carrier.pillar[n]arene are the fifth-generation macrocyclic supramolecular host compounds with excellent molecular recognition functions.Gold nanoparticles(AuNPs)have good catalytic properties.In this paper,hybrid material based on hydroxylatopillar[n]arene,AuNPs,and CNCs is designed and used to construct a hybrid material for detection of pesticides methyl parathion(MP)and imidacloprid(IDP).Compared with the reported similar methods,the sensor has the advantages of fast,high sensitivity and low detection limit(LOD).In addition,the catalytic degradation of methylene blue(MB)and the catalytic reduction of p-nitrophenol(4-NP)by hybrid materials were studied.The results show that the hydroxylatopillar[n]arene,AuNPs,and CNC can secondary recovery and recycling,and the catalytic performance is higher than the binary hybrid material of hydroxylatopillar[n]arene and AuNPs.The following is the main content of this paper:(1)The hybrid materials HP6@AuNPs were prepared and characterized by TEM and XPS.The electrochemical sensor for IDP was constructed by HP6@AuNPs.The HP6@AuNPs/GCE with the highest response to IDP was obtained by comparing the cyclic voltammetry(CV),differential pulse curve(DPV)and impedance spectrum(EIS)of bare electrode(GCE)and HP6@AuNPs/GCE in 195.5?M IDP solution.The LOD of IDP was 0.065?M.Compared with the reported similar methods,the sensor based on HP6@AuNPs hybrid material has great advantages,reflecting the great prospect in practical application.(2)The hybrid material HP5@AuNPs was prepared and reduced graphene oxide(ERGO)was introduced to construct the electrochemical sensor HP5@AuNPs-ERGO for MP detection.HP5@AuNPs,ERGO and HP5@AuNPs-ERGO were characterized by TEM,FT-IR and XPS.The CV,DPV and EIS in[Fe(CN)6]3-/4-were measured in MP solution.The linear range of the electrochemical sensor was 0.001-0.01?M,0.01-38?M and LOD was 0.001?M.Compared with the reported similar methods,the sensor based on HP5@AuNPs-ERGO hybrid material has great advantages,which embodies the value in practical application.(3)Hydrogen peroxide(H2O2)and Fe2SO4·4H2O were used to catalyze the reaction of H2O2 to produce protons(H+)and hydroxyl radicals.H+destroys the oxygen bridge,causing hydrolysis of the amorphous region of cellulose.At the same time,Hydroxyl radicals attacks the hydroxyl to form carboxylic acid group and carboxylated CNCs.TEM showed that the distribution of CNCs was relatively dispersed.The results show that the maximum equilibrium adsorption capacity and adsorption efficiency of CNCs are 82.9 mg·g-1 and 82.9%respectively.HP6 and 2HP6 were designed and synthesized.HP6@AuNPs and 2HP6@AuNPs hybrid materials were prepared by the redox reaction between HP6 and 2HP6 terminal hydroxyl groups and chloroauric acid.The electrostatic interactions between HP6@AuNPs-CNC and 2HP6@AuNPs-CNC hybrid nanomaterials were prepared.TEM showed that the AuNPs were on CNC,indicating that the ternary hybrid materials was successfully prepared.The composite nanomaterial HP6/2HP6@AuNPs-CNC was used to degrade the MB and reduce 4-NP.By comparing HP6@AuNPs/2HP6@AuNPs and HP6@AuNPs-CNC/2HP6@AuNPs-CNC,it was found that the catalytic ability of HP6@AuNPs-CNC/2HP6@AuNPs-CNC was not weakened,but the turnover frequency(TOF)was increased from 2420 h-1 to 2610 h-1 and 2530 h-1 to 2875 h-1,and the reasons were analyzed.The experiment of the catalyst's cycle catalytic capacity was carried out 10 times,and the results showed that the catalytic capacity of the catalyst was still as high as more than 90%.This work has a broad industrial application prospect for the recovery and utilization of nano catalyst supported on CNC. |
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