基于MWCNT/TiO2对电极和硫醇盐/二硫化物非碘氧化还原电对的染料敏化太阳能电池性能

采用水热法合成出多壁纳米碳管/二氧化钛(MWCNT/TiO₂)复合物, 并作为染料敏化太阳能电池(DSSC)中对电极材料并组装成电池. 通过场发射扫描电子显微镜(FE-SEM)、傅里叶变换红外(FTIR)光谱、X射线粉末衍射(XRD)、同步热重-差示扫描量热(TGA-DSC)、拉曼(Raman)光谱和光电子能谱(XPS)等方法对其形貌、组成和结构进行表征. 结果表明, 酸化MWCNT表面―COOH与水热生长出的锐钛矿TiO₂表面―OH之间, 通过形成类似于O＝C―O―Ti 或者C―O―Ti 的结构, 能有效地增强复合物薄膜层与导电玻璃基底之间的相互作用. 通过循环伏安(CV)、电化学阻抗谱(EIS)、塔菲尔曲线(Tafel)和电池的伏安特性曲线等方法研究了该类对电极对硫醇盐/二硫化物(T-/T₂)非碘氧化还原电对的光电化学特性. 结果表明: 当MWCNT与TiO₂质量比为3:1时, 基于该复合物对电极与T-/T₂非碘氧化还原电对所组装DSSC的开路电压为0.63 V, 短路电流为15.81 mA·cm^-2, 填充因子为0.65, 光电转换效率达到6.47%.

Dye-Sensitized Solar Cells Based on MWCNT/TiO2 Counter Electrode and Thiolate/Disulfide Non-Iodine Redox Couple

Multi-walled carbon nanotube (MWCNT)/TiO₂ composites were prepared using acid-treated MWCNT and titanium (IV) isopropoxide by a facile hydrothermal method. The morphology and structure of composites were characterized by field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis with differential scanning calorimetry (TGA-DSC), Raman and X-ray photoelectron spectroscopy (XPS). The results show that the cohesion effect of MWCNT/TiO₂ was due to the interaction between ―COOH group of acid-treated MWCNT and ―OH group of the anatase TiO₂ surface, which might form a similar chemical bonding (O＝C―O―Ti or C―O―Ti) interaction. The photoelectrochemical performance of dye-sensitized solar cell (DSSC) based on both MWCNT/TiO₂ counter electrode and thiolate/disulfide (T-/T₂) non-iodine redox couple was investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Tafel and voltage-photocurrent density curves. The results indicate that the reduction of T₂ to T^- at MWCNT/TiO₂ counter electrode was more effective than that of Pt counter electrode. Under optimized conditions (m(MWCNT)/m(TiO₂), mass ratio), DSSC achieved an optimal performance, such as open-circuit voltage of 0.63 V, short-circuit photocurrent density of 15.81 mA·cm^-2, fill factor of 0.65, and photon-to-electron conversion efficiency of 6.47%.