硅酸锆包裹硫硒化镉色料的溶胶共沉淀合成

采用溶胶共沉淀法替代工业上已产业化的固相法,成功制备了硅酸锆包裹硫硒化镉色料。采用分段升温的方式对前驱体进行热处理来验证关于包裹率的影响因素的推断,并且模拟还原气氛来保护整个热处理过程。同时通过XRD、SEM、FTIR等一系列手段对合成产物进行表征,证实将发色前驱体的制备放到液相反应中的确能有利于反应物的均匀接触与混合,且包裹率由过去的1%~2%提高到6%以上。

永冲电化学腐蚀制备n型多孔硅及其发光性能

采用脉冲电化学腐蚀法，以n型单晶硅为衬底制备多孔硅（n—PS），通过扫描电镜（SEM）、室温500—700nm范围内荧光光谱，系统研究腐蚀时间、占空比和脉冲频率对n-PS的结构形貌和可见光区室温光致发光特性（PL）的影响，结果表明，相比直流电化学腐蚀方法，脉冲腐蚀能获得孔径分布均匀且发光强度更高的多孔硅；随腐蚀时间、占空比和脉冲频率等腐蚀条件的变化，其发光峰位及发光强度均有明显改变；当等效腐蚀时间为30min、占空比为0．5、脉冲频率为10Hz时，制备的n—PS的PL强度较高，发光性能较好。

Surface modification of coconut-based activated carbon by SDS and its effects on Pb^(2+) adsorption

Coconut-based activated carbons were modified with sodium dodecyl sulfate (SDS). The activated carbons, which were modified by different concentrations of SDS, were characterized by acid/base titrations, textural analysis (BET), atomic absorption spectrochemical analysis and Zeta potential measurements. The effects of SDS modification on Pb2+ absorption were studied further. The results indicate that after the modification of SDS, there are new functional groups on the surface of modified activated carbons and the number of functional group has changed remarkably, the total acidity decreases observably, but the total alkalinity increases dramatically. With the increase of surface load with SDS, the Pb2+ adsorption mass of activated carbons increases and the optimal pH for Pb2+ adsorption of the SDS modified activated carbons is 5. The experimental data are simulated better by Freundlich isotherm model for the modified activated carbons, and the experimental data are simulated better by Langmuir isotherm model for unmodified ones.