微乳法制备棒状ZnO材料及其光催化性能
|
摘要
采用浊度法绘制十六烷基三甲基溴化铵(CTAB)/正丁醇/环己烷/硝酸锌或草酸铵水溶液体系的拟三元相图,确定微乳液稳定区域最大时CTAB与正丁醇的质量比为1∶1。在此条件下,选择m(CTAB+正丁醇)∶m(环己烷)=3∶7,以硝酸锌和草酸铵为原料,采用微乳法制备ZnO的前驱体二水合草酸锌,然后通过煅烧得到ZnO样品。考察水与CTAB的摩尔比(R)和反应物浓度对ZnO材料结构、形貌、光学性质和光催化性能的影响。实验结果表明:ZnO样品为纯的六方纤锌矿结构晶体,形貌均为棒状,且样品的尺寸随R值和反应物浓度的不同而不同。在300 W汞灯紫外光照射下,ZnO样品对亚甲基蓝溶液均具有较好的光催化性能,光催化反应过程符合准一级反应动力学。其中,在反应物浓度为0.15 mol/L,R=15条件下制备的ZnO样品在光照90 min时可使亚甲基蓝的降解率达到97.0%,且降解反应速率常数k最大,其光催化性能最好。
Pseudo-ternary phase diagrams of microemulsion system of hexadecyltrimethylammonium bromide( CTAB)/n-butanol/cyclohexane/zinc nitrate or ammonium oxalate solution were drawn by turbidimetry,and the best mass ratio of CTAB to n-butanol was 1∶ 1 in the maximum stable region of microemulsion. Under this condition,when m( CTAB + n-butanol) ∶ m( cyclohexane) was 3 ∶ 7,zinc oxalate dihydrate,which was the precursor of ZnO,was prepared by a microemulsion method using zinc nitrate and ammonium oxalate as raw materials. ZnO materials were prepared by calcining zinc oxalate dihydrate. The effects of R( the molar ratio of water to CTAB) and reactant concentration on the structure,morphology,optical property and photocatalytic property of ZnO materials were studied. Results show that the morphologies of ZnO power are rodlike and they exhibit hexagonal wurtzite structure. The sizes of samples are affected by R and reactant concentration. All the samples have good photocatalytic effect on the catalytic degradation of methylene blue solution under the irradiation of 300 W Hg lamp,and the photocatalytic degradation process follows quasi-first-order kinetics.Among which the degradation rate of methylene blue solution achieves 97. 0% for 90 min illumination and the corresponding reaction rate constant k is the largest,and with best photocatalytic property,when the reactant concentration is 0. 15 mol/L,R = 15.
Pseudo-ternary phase diagrams of microemulsion system of hexadecyltrimethylammonium bromide( CTAB)/n-butanol/cyclohexane/zinc nitrate or ammonium oxalate solution were drawn by turbidimetry,and the best mass ratio of CTAB to n-butanol was 1∶ 1 in the maximum stable region of microemulsion. Under this condition,when m( CTAB + n-butanol) ∶ m( cyclohexane) was 3 ∶ 7,zinc oxalate dihydrate,which was the precursor of ZnO,was prepared by a microemulsion method using zinc nitrate and ammonium oxalate as raw materials. ZnO materials were prepared by calcining zinc oxalate dihydrate. The effects of R( the molar ratio of water to CTAB) and reactant concentration on the structure,morphology,optical property and photocatalytic property of ZnO materials were studied. Results show that the morphologies of ZnO power are rodlike and they exhibit hexagonal wurtzite structure. The sizes of samples are affected by R and reactant concentration. All the samples have good photocatalytic effect on the catalytic degradation of methylene blue solution under the irradiation of 300 W Hg lamp,and the photocatalytic degradation process follows quasi-first-order kinetics.Among which the degradation rate of methylene blue solution achieves 97. 0% for 90 min illumination and the corresponding reaction rate constant k is the largest,and with best photocatalytic property,when the reactant concentration is 0. 15 mol/L,R = 15.
引文
[1]Kim K,Moon T,Lee M,et al.Light-cmitting diodes composed of nZn O and p-Si nanowires constructed on plastic substrates by dielectrophoresis[J].Solid State Sciences,2011,13(9):1735-1739.
[2]Lee C P,Li C T,Fan M S,et al.Microemulsion-assisted zinc oxide synthesis:morphology control and its applications in photoanodes of dye-sensitized solar cells[J].Electrochimica Acta,2016,210:483-491.
[3]Bai S L,Chen L Y,Chen S.Reverse microemulsion in situ crystallizing growth of Zn O nanorods and application for NO2sensor[J].Sensors and Actuators B:Chemical,2014,190:760-767.
[4]Wang N N,Zheng T,Zhang G S,et al.A review on fenton-like processes for organic wastewater treatment[J].Journal of Environmental Chemical Engineering,2016,4:762-787.
[5]Dindar S,Icli J.Unusual photoreactivity of znic oxide irradiated by concentrated sunlight[J].Journal of Photochemistry and Photobiology A:Chemistry,2001,140(3):263-270.
[6]Thambidurai M,Muthukumarasamy N,Velauthapillai D,et al.Synthesis of Zn O nanorods and their application in quantum dot sensitized solar cells[J].Journal of Sol-Gel Science and Technology,2012,64:750-755.
[7]De la Rosa E,Sepúlveda-Guzman S,Reeja-Jayan B.Controlling the growth and luminescence properties of well-faceted Zn O nanostry rods[J].The journal Physical Chemistry C,2007,111(24):8489-8495.
[8]Saravanan R,Thirumal E,Gupta V K,et al.The photocatalytic activity of Zn O prepared by simple thermal decomposition method at various temperatures[J].Journal of Molecular Liquids,2013,177:394-401.
[9]Lu F,Cai W P,Zhang Y G,et al.Zn O hierarchical micro/nanoarchitectures:solvothermal synthesis and structurally enhanced photocatalytic performance[J].Advanced Functional Materials,2008,18:1047-1056.
[10]Kumar S,Surendar T,Das D,et al.Hierarchical Zn O“rod like”architecture synthesized via reverse micellar route for improved photocatalytic activity[J].Material Letters,2013,101:33-36.
[11]滕洪辉,徐淑坤,王猛.微乳液法合成不同维度氧化锌纳米材料及其光催化活性[J].无机材料学报,2010,25(10):1134-1140.
[12]杨则恒,吴情,张俊,等.微乳液调控制备Zn O微米花薄膜及其光催化性能[J].硅酸盐学报,2014,42(1):75-79.
[13]Liu Y M,Lv H,Li S Q,et al.Synthesis and characterization of Zn Omicrostructures via a cationic surfactant-assisted hydrothermal microemulsion process[J].Materials Characterization,2011,62(5):509-516.
[14]Jiang J Y,Huang Z Y,Tan S W,et al.Preparation of Zn O nanosheets by a novel microemulsion-based hydrothermal method[J].Materials Chemistry and Physics,2012,132:735-739.
[15]Rajeev R,Sonalika V,Pallavi T,et al.Controlling size,morphology,and aspect ratio of nanostructure using reverse micelles:A case study of copper oxalate monohydrate[J].Langmuir,2009,25(11):6469-6475.
[16]张立言,王芬,朱建锋,等.反相微乳液法合成Zn O纳米棒及其生长机理研究[J].人工晶体学报,2011,40(5):1224-1228.
[17]Wang F,Qin X F,Zhu D D,et al.PEG-assisted hydrothermal synthesis and photoluminescence of flower-like Zn O microstructures[J].Materials Letters,2014,117:131-133.
[18]Zhang D H,Wang Q P,Xue Z Y,et al.Photoluminescence of Zn O films excited with light of different wavelength[J].Applied Surface Science,2003,207:20-25.
[19]Kislov N,Lahiri J,Verma H,et al.Photocatalytic degradation of methyl orange over single crystalline Zn O:orientation dependence of photoactivity and photostability of Zn O[J].Langmuir,2009,25(5):3310-3315.
[2]Lee C P,Li C T,Fan M S,et al.Microemulsion-assisted zinc oxide synthesis:morphology control and its applications in photoanodes of dye-sensitized solar cells[J].Electrochimica Acta,2016,210:483-491.
[3]Bai S L,Chen L Y,Chen S.Reverse microemulsion in situ crystallizing growth of Zn O nanorods and application for NO2sensor[J].Sensors and Actuators B:Chemical,2014,190:760-767.
[4]Wang N N,Zheng T,Zhang G S,et al.A review on fenton-like processes for organic wastewater treatment[J].Journal of Environmental Chemical Engineering,2016,4:762-787.
[5]Dindar S,Icli J.Unusual photoreactivity of znic oxide irradiated by concentrated sunlight[J].Journal of Photochemistry and Photobiology A:Chemistry,2001,140(3):263-270.
[6]Thambidurai M,Muthukumarasamy N,Velauthapillai D,et al.Synthesis of Zn O nanorods and their application in quantum dot sensitized solar cells[J].Journal of Sol-Gel Science and Technology,2012,64:750-755.
[7]De la Rosa E,Sepúlveda-Guzman S,Reeja-Jayan B.Controlling the growth and luminescence properties of well-faceted Zn O nanostry rods[J].The journal Physical Chemistry C,2007,111(24):8489-8495.
[8]Saravanan R,Thirumal E,Gupta V K,et al.The photocatalytic activity of Zn O prepared by simple thermal decomposition method at various temperatures[J].Journal of Molecular Liquids,2013,177:394-401.
[9]Lu F,Cai W P,Zhang Y G,et al.Zn O hierarchical micro/nanoarchitectures:solvothermal synthesis and structurally enhanced photocatalytic performance[J].Advanced Functional Materials,2008,18:1047-1056.
[10]Kumar S,Surendar T,Das D,et al.Hierarchical Zn O“rod like”architecture synthesized via reverse micellar route for improved photocatalytic activity[J].Material Letters,2013,101:33-36.
[11]滕洪辉,徐淑坤,王猛.微乳液法合成不同维度氧化锌纳米材料及其光催化活性[J].无机材料学报,2010,25(10):1134-1140.
[12]杨则恒,吴情,张俊,等.微乳液调控制备Zn O微米花薄膜及其光催化性能[J].硅酸盐学报,2014,42(1):75-79.
[13]Liu Y M,Lv H,Li S Q,et al.Synthesis and characterization of Zn Omicrostructures via a cationic surfactant-assisted hydrothermal microemulsion process[J].Materials Characterization,2011,62(5):509-516.
[14]Jiang J Y,Huang Z Y,Tan S W,et al.Preparation of Zn O nanosheets by a novel microemulsion-based hydrothermal method[J].Materials Chemistry and Physics,2012,132:735-739.
[15]Rajeev R,Sonalika V,Pallavi T,et al.Controlling size,morphology,and aspect ratio of nanostructure using reverse micelles:A case study of copper oxalate monohydrate[J].Langmuir,2009,25(11):6469-6475.
[16]张立言,王芬,朱建锋,等.反相微乳液法合成Zn O纳米棒及其生长机理研究[J].人工晶体学报,2011,40(5):1224-1228.
[17]Wang F,Qin X F,Zhu D D,et al.PEG-assisted hydrothermal synthesis and photoluminescence of flower-like Zn O microstructures[J].Materials Letters,2014,117:131-133.
[18]Zhang D H,Wang Q P,Xue Z Y,et al.Photoluminescence of Zn O films excited with light of different wavelength[J].Applied Surface Science,2003,207:20-25.
[19]Kislov N,Lahiri J,Verma H,et al.Photocatalytic degradation of methyl orange over single crystalline Zn O:orientation dependence of photoactivity and photostability of Zn O[J].Langmuir,2009,25(5):3310-3315.