自支撑多孔硅/ZnO复合材料的制备及其超级电容特性

首先利用二步阳极氧化法制备了自支撑多孔硅,再利用真空抽滤法在自支撑多孔硅中沉积ZnO纳米籽晶层,最后用水热合成法使ZnO纳米籽晶进一步长大。采用扫描电子显微镜、X射线能谱分析和光致发光谱分析对样品的形貌、元素及发光性能进行了表征。结果表明:自支撑多孔硅内部成功填充了ZnO纳米颗粒并形成了自支撑多孔硅/ZnO复合材料。将这种复合材料作为超级电容器电极进行了电化学测试,包括循环伏安、阻抗谱和恒电流充放电测试,该复合材料有较好的超级电容特性,比容量可达到15.7F/g,相比于自支撑多孔硅提高120倍。

Preparation of freestanding porous silicon/ZnO composites and its supercapacitor property

Two step anodic oxidation method was firstly used to prepare freestanding porous silicon. Then ZnO nanocrystal layer was deposited in the freestanding porous silicon using vacuum filtration method and hydro-thermal synthesis approach was used for further growth of ZnO nanocrystals finally. The morphology, element and luminescence properties of the samples were characterized by scanning electron microscope, X-ray energy dispersive spectrum analysis and photoluminence spectrum analysis. The results show that ZnO nanoparticles exist in the freestanding porous silicon and porous silicon/ZnO composites form successfully. Moreover, the electrochemical tests of the composites as a supercapacitor electrode was conducted by cyclic voltamerty, impendance spectrum and galvanostatic charge/discharge tests. The composites have good supercapacitor property. The specific capacitances can reach 15.7 F/g, with an increase of 120 times compared with the freestanding porous silicon.