“Stöber”模板法制备Ag@C纳米粒子及其催化性能

Preparation of Ag@C nanoparticles by“Stöber”template method and its catalytic performance

采用“Stöber”模板法合成了核-壳-壳结构的Ag@SiO_(2)@RF复合纳米粒子,经过碳化、刻蚀得到了“Rattle型”结构的Ag@C纳米粒子。采用透射电镜(TEM)、扫描电镜(SEM)、拉曼光谱(RS)、N2吸附及X线粉末衍射(XRD)表征检测,对其形貌、结构进行表征。结果表明:制备的Ag@C纳米粒子具有完整的球形结构、较大的空腔和可移动的纳米银内核,壳层上有介孔,平均孔径为7.8 nm,比表面积为866 m2/g。以2 mg Ag@C为催化剂,室温下用过量的KBH4还原1 mmol/L对硝基苯酚,测试Ag@C纳米粒子的催化性能。结果表明:反应3 min,其转化率为98%,催化剂使用6次活性没有明显下降。

Ag@SiO_(2)@RF composite nanoparticles with core-shell-shell structure were synthesized by“Stöber”template method.After carbonization and etching,Ag@C nanoparticles with“Rattle”structure was obtained.The morphology and structure of nanoparticles were characterized by transmission electron microscope,scanning electron microscope,Raman spectroscopy(RS),nitrogen adsorption and X-ray powder diffraction.It turned out that Ag@C nanoparticles were porous spheres with great cabity and a movable silver nanocore.They possessed high surface area(up to 866 m2/g)and mesopore size(7.8 nm).The reduction of pnitrophenol by KBH4 was used as a model reaction to test the catalytic properties of prepared Ag@C nanoparticles.At room temperature,1 mmol/L p-nitrophenol was reduced by 2 mg Ag@C with excess potassium borohydride with conversion of 98% within 3 min,as well as remained activity after recycled more than 6 times.