有机硅功能化碳微球可见光催化还原六价铬

Organosilane Functionalized Carbon Microspheres as Efficient Photocatalyst for Reducing Cr(Ⅵ)Under Visible Light Irradiation

以柠檬酸铵为碳源,3-氨丙基三乙氧基硅烷(APTES)为功能化试剂,采用热分解法制备了有机硅功能化的碳微球(SiCMS).利用X射线衍射(XRD)、透射电子显微镜(TEM)、紫外可见漫反射光谱(UVVisDRS)、光电流响应和光致发光光谱(PL)等对SiCMS的结构和性能等进行了表征.结果表明:制备的SiCMS呈球形形貌,尺寸在40~200 nm范围,在可见光区具有强的光吸收和光电流响应特性;甲酸存在下,可见光照射140 min,SiCMS对100 mg·L^-1K2Cr2O7溶液中Cr^6+的还原率可达96%;经过4次循环使用,SiCMS对于Cr(Ⅵ)的还原率能够维持在91%,说明SiCMS作为光催化剂具有良好的稳定性与重复使用性.

Organosilane functionalized carbon microspheres(SiCMS)were synthesized through pyrolytic method using ammonium citrate as carbon source and 3-aminopropyltriethoxysilane(APTES)as functional reagent.The obtained SiCMS were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),UV-visible diffuse reflectance spectroscopy(UV-Vis-DRS),photocurrent response,and photoluminescence spectroscopy(PL),etc.The results indicate that SiCMS have a spherical morphology with a size of 40~200 nm.Moreover,the SiCMS exhibited strong light-harvesting capability and photocurrent response under visible light irradiation.The as synthesized SiCMS showed a superior catalytic activity with 96%of Cr(Ⅵ)reduction efficiency to 100 mg·L^-1K2Cr2O7 solution within 140 min under visible light irradiation,by using formic acid as a reducing agent.Additionally,SiCMS can keep photoactivity of 91%for Cr(Ⅴ)reduction in 140 min after four catalytic cycles,suggesting that SiCMS have excellent stability and reusability as photocatalyst.