| Adsorpttion and catalytic degradation are two common methods for the treatment of organic wastewater.Among various adsorbents,mesoporous silica?SiO2?has been wildy studied due to its merits of large specific surface area,high pore volume,and adjustable and controllable pore diameter.In real applications,using adsorption method to remove the polltants easily leads to secondary pollution.As a result,this thesis aim to farication of a series of bifunctional mesoporous SiO2 related materials,which have both high adsorption capacities and superior catalytic acitivities.Active metal species?Cu,Fe,and Co?were incoparated into the structure of mesoporous SiO2 through methods of in situ hydrothermal syhesis and the grinding-assistant self-infiltration.Methylene lue?MB?aqueous solution was used as model wasterwater to detect the adsorption/catalytic property of the functional mesoporous SiO2.The relationships between the porous structures and the adsorption/catalytic properties for the materials were investigated.Effects of metal species on the catalytic activity for the materials were also throughly studied.Detailed contents of this thesis were divided into following four parts.1.Copper?Cu?modified mesoporous silica?FCuNx?was directly synthesized in a mildly acidic condition using a one-step hydrothermal method.The amount of Cu in the synthesis?rCu:Si?has great effulence on the pore structure and chemical compostion of the obtained material.Results show that the specific surface area of the obtained material(586248 m2·g-1)is gradually decreased while the primary pore size does not change much?8.810.5 nm?.The FCuN0.5 sample synthesized with r Cu:Si=0.5 has the largest adsorption capacity(99 mg·g-1)among all the composites.The FCuN1.0 sample synthesized with rCu:Si=1.0 has the best catalytic property,which has a removal efficiency of 91%for degradation of high-concentrated MB(180 mg·L-1).Meanwhile,FFCuN1.0 also has the good cycle ability and it still can remove 84%of MB after five recycling tests.2.Ferric?Fe?modified mesoporous silica?FFeCx?was further synthesized in the mildly acidic condition containing Fe species through using the one-step hydrothermal method.The obtained material has the highly ordered mesostructue,large surface area(526889 m2·g-1),and pore size in the range of 11.812.4 nm.Fe is incorparatd in the matrix of FFeCx material as both extra-framwork and framework forms.The adsorption capability of the material decreases while catalytic ability enhances with increasing the Fe content in the sample.The FFeC0.05 sample synthesized with rFe:Si=0.05 can 100%remove the MB from aqueous solution(180 mg·L-1).Removal efficiency for the higher concentrated MB of 210 and 250 mg?L-1 are 95%and 85%,respectively by FFeC0.05.3.Ferric?Fe?modified mesoporous SiO2?FFeGx?was successfully synthesized via a grinding-assistant self-infiltration method using the template-containing mesoposou SiO2 and FeCl3 as precursors with the subsequent cacinations.Surface area(1222402 m2·g-1)of the obtained material increases firstly then decrease.Pore size of the sample?8.4110.58 nm?enlarges with the Fe content was enhacing.The FFeG0.12sample synthesized with rFe:Si=0.12 can 100%remove the high concentrated MB(300 mg·L-1)from aqueous solution.Moreover,it also presents excellent stability and recycle property.For MB of 300 mg·L-1,the removal efficiency maintains in 94%when the FFeG0.12 catalyst was recycled for five times.4.Mesoporous SiO2 was also tried to be modified by cobalt?Co?species via the same grinding-assistant self-infiltration method.Property of the finnaly abtained material?FCoGx?was detected by various techniques.Surface area(586444 m2·g-1)of FCoGx decreases when Co content was enhanced.Pore size of the sample is in the range of 9.2310.57 nm.The FCoG0.1 sample synthesized with rCo:Si=0.1 can 100%remove MB of 120 mg·L-1.It also can remove about 138 mg?g-1 of MB form the higher concentrated solution(180 mg·L-1).Obviously,the MB removal efficiency of mesoporous SiO2 is improved when the sample was modified by Co species.However,the Co-modified mesoporous SiO2?FCoGx?has a relatively lower capability than the Cu-and Fe-modified samples when they were apllied in the removal of MB from wasterwater. |
PDF Full Text Request