采用水热法合成出多壁纳米碳管/二氧化钛(MWCNT/Ti O2)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Ti O2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Ti O2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 m A·cm-2,填充因子为0.65,光电转换效率达到6.47%.
Multi-walled carbon nanotube(MWCNT)/Ti O2 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/Ti O2 was due to the interaction between ―COOH group of acid-treated MWCNT and ―OH group of the anatase Ti O2 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/Ti O2 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/Ti O2 counter electrode was more effective than that of Pt counter electrode. Under optimized conditions(m(MWCNT)/m(Ti O2), mass ratio), DSSC achieved an optimal performance, such as open-circuit voltage of 0.63 V, short-circuit photocurrent density of 15.81 m A·cm^-2, fill factor of 0.65, and photon-to-electron conversion efficiency of 6.47%.