新颖树枝状和海胆状硫化镉纳米晶的水热法合成及光催化性能研究

以硝酸镉、硫脲为起始原料,氯代十六烷基吡啶(CPC)、十六烷基三甲基溴化铵(CTAB)为配位剂,采用水热法合成了树枝状和海胆状的三维纳米晶CdS(Ⅰ)和CdS(Ⅱ).采用XRD、FE-SEM、XPS和UV-Vis等测试手段对样品的形貌、尺寸、结构和相组成进行了表征,以延安卷烟厂废水作为目标源对样品的活性进行了检测.XRD和XPS结果表明,所得样品为六方晶系的纤锌矿CdS,样品的纯度高,且样品CdS(Ⅰ)的(002)衍射峰比较强,说明所得CdS优先沿着c-轴生长.FE-SEM照片显示,CdS(Ⅰ)纳米晶为树枝状结构,而样品CdS(Ⅱ)则为海胆状结构.光催化活性研究表明,在太阳光照射下样品CdS(Ⅰ)和CdS(Ⅱ)对延安卷烟厂废水具有较强的光催化活性,且CdS(Ⅰ)纳米晶的活性高于CdS(Ⅱ).当CPC的浓度为5%时,所得CdS对废水的光催化活性最高,太阳光下连续照射5h,废水CODCr去除率达93.4%.

Syntheses of dendritic and urchin-like CdS nanocrystal by hydrothermal method and it's photocatalytic activity

Three-dimensional(3D) CdS nanocrystals with dendritic and urchin-like morphology were synthesized by a facile hydrothermal treatment from Cd(NO3)3 and thiourea,Cetyltrimethyl Ammonium Bromide(CTAB) and Cetylpyridinium Chloride(CPC)were acted as the capping reagents.The morphology,size,structure and phase composition of CdS nanostructure were characterized by X-ray diffraction(XRD),filed-scanning electron microscope(FE-SEM),X-ray photoelectron spectroscope(XPS)and UV-vis absorption spectrum techniques.The waste water of Yan'an cigarette factory was chosen as a target source to evaluate the photocatalytic activity of the as-synthesized CdS.XRD and XPS results confirmed that the as-synthesized sample were hexagonal wurtzite phase,pure CdS.It could be also noted that,the(002)reflection peak of sample CdS(Ⅰ) was comparatively strong,which could be the preferential crystal growth orientation along the c-axis.FE-SEM images clearly indicated that CdS(Ⅱ)nanocrystals exhibited a dendritic nanostructure,while the sample CdS(Ⅱ)showed a urchin-like nanostructure.Furthermore,the photocatalytic activity experiment illustrated that as-synthesized urchin-like and dendritic CdS nanostructure exhibited an excellent photocatalytic performance to waste water under the salar illuminance.The comparative experiment results also suggested that dendritic CdS nanostructure was more effective than urchin-like CdS catalyst for decolorization of waste-water.When the concentration of CPC was 5 %,the as-synthesized CdS(Ⅰ) exhibited high photocatalytic activity,and CODCr removal of cigarette factory wastewater reached 93.4 % with 5h solar illumunance.