摘要
在恒定直流下,采用高纯石墨棒为原料,混合无机酸溶液为电解液,采用一步电化学剥离法制备石墨烯(G),所制备的G可稳定分散在N,N-二甲基甲酰胺(DMF)溶液中。以钛酸丁脂和G为前驱物,采用溶胶-凝胶法在N2氛围和高温加热下制备出G/nano TiO_2复合光催化材料;利用XRD、FTIR、紫外-可见分光光度计(UV-Vis)、XPS、SEM和TEM等技术对G和G/nano TiO_2复合材料进行了结构性能及微观形态表征。以3,5-二硝基水杨酸(DNS)为探针物,研究了在缺氧的水体中G/nano TiO_2不同投加量的光催化效率与DNS降解机制。结果表明:采用恒压一步电化学剥离法所制备的G层与层之间剥离程度良好,片层通透性较高,六碳环上生成的含氧活性基团较少,G共轭π键结构保持良好;所制备的G/nano TiO_2复合材料中TiO_2结晶良好,颗粒紧密结合,且被固定在有褶皱的G上;降解实验发现,G/nano TiO_2复合材料具有降解DNS良好性能,且投加量对其光催化活性有直接的影响;在缺氧状态下,DNS主要发生光催化还原反应,使苯环上的硝基还原成氨基,生成5-氨基水杨酸和苯三酚等中间产物,部分发生光催化氧化反应,生成CO_2和H2O。
A stable dispersion in mixed solvent of water and N,N-dimethyl formamide（DMF）of graphene（G）was synthesized by constant voltage one-step electrochemical approach using a high-purity graphite rod as the raw material and mixed acid as the electrolyte.The G/nanoTiO2 photocatalytic composites were prepared by the method of sol-gel and high temperature heating under nitrogen protection using butyl titanate ester and G as the precursors.The structural properties and microcosmic morphology of the graphite stripping product were characterized by using XRD,FTIR,ultraviolet-visible spectroscopy（UV-Vis）,XPS,SEM and TEM.The photocatalytic properties in the anoxic water of different G/nano TiO2 composites dosages were studied by using 3,5-dinitrosalicylic acid（DNS）as the probe and ultraviolet light as the light source.The results show that distance between layer is enlarged,layers have high transmittance and less reactive groups are generated on six carbon ring and the conjugatedπbond structure of G get good maintain by the method of constant voltage one-step electrochemical.The as-prepared G/nano TiO2 microcosmic morphology shows that well crystallized,closely combined with the TiO2 is found to be deposited on G.The degradation experiment shows that G/nano TiO2 composites have good performance for the photocatalytic deg-radation of DNS,and photocatalytic activity has a direct influence by different dosages.The nitryl become amino in benzene ring,the middle products of 5-aminosalicylic acid or phloroglucinol are produced from the photocatalytic reduction reaction of DNS under the anoxic condition,part of DNS is decomposited and CO2 and H2 O are generated by photocatalytic oxidation.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2018年第1期142-149,共8页
Acta Materiae Compositae Sinica
基金
教育部高等学校科技创新工程重大项目培育资金(708058)
江西省研究生创新专项资金(省级项目)
关键词
石墨烯
电化学
TiO2
复合材料
光催化降解
graphene
electrochemical
TiO2
composites
photocatalytic degradation
