硫化氧化两步法提高(110)取向ZnO纳米片比表面及其光电极应用

以硫代乙酰胺为硫源, 通过一种较温和的溶剂热法先将生长于氟掺杂的SnO₂ (FTO)导电玻璃上的ZnO纳米片硫化, 再将其在空气中高温焙烧氧化,利用ZnO/ZnS晶格的膨胀收缩效应使ZnO纳米片表面粗糙化,达到提高其比表面积的目的. 系统研究了该硫化氧化两步法中ZnO纳米片、硫化后的ZnS纳米片、硫化氧化后的ZnO纳米片薄膜的形貌、物相、比表面积及孔径分布的变化. 并将硫化氧化前后两种ZnO纳米片阵列薄膜制成染料敏化太阳电池的光电极, 分别对电池的电流密度-电压(J-V)特性进行了表征. 实验结果表明, 经过硫化氧化后的ZnO纳米片的比表面积大约是未经该处理的ZnO纳米片的2倍, 同时前者的太阳电池光电转换效率(IPCE)相对于后者提高33%.

Increasing Specific Surface Area of (110)-Oriented ZnO Nanosheets by Sulfuration-Oxidization Treatment for Photoelectrode Applications

To increase the specific surface area of ZnOnanosheets, a sulfuration and oxidization treatment was introduced. First, ZnO nanosheets were grown by the hydrothermal method at a low temperature on the conductive side of the fluorine-doped tin oxide (FTO) conductive glass. The same method was then used to obtain ZnS nanosheets by dipping the FTO with ZnO nanosheets into the precursor of the thioacetamide aqueous solution. In the end, ZnO nanosheets were gained again by sintering ZnS nanosheets at a high temperature in an air atmosphere. The effects of the treatment on ZnO nanosheets were studied with respect to morphology, structure, specific surface area, and pore size distributions. The results showed that the specific surface area of ZnO nanosheets can be doubled after the sulfuration and oxidization treatment. The samples were also introduced into the photoelectrode of dye-sensitized solar cells (DSSCs) and their dye-loading, current density-voltage (J-V), and the monochromatic incident photon-to-electron conversion efficiency (IPCE) were characterized and compared. The results showed that both the dye-loading and IPCE were increased via the sulfuration and oxidization treatment. Above all, the energy conversion efficiency of DSSCs was found to increase by 33%.