Saranya K, Subramani A, Sivasankar N, Bhargava P
J Nanosci Nanotechnol. 2017 Jan;17(1):398-404. doi: 10.1166/jnn.2017.12542.
One-dimensional graphitized carbon nanofibers (G-CNFs) were prepared by employing facile electrospinning technique using 10 wt% of polyacrylonitrile (PAN) solution in N,N-dimethyl formamide (DMF) as precursor followed by successive stabilization, carbonization and purification processes. Cobalt sulfide (CoS) nanoparticles were grown onto G-CNFs by hydrothermal method using cobalt chloride and L-cysteine as precursors. The results of X-ray diffraction (XRD) and Raman spectroscopy confirmed the phase formation and degree of graphitization, respectively. Field-emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) images confirmed the morphology, growth and distribution of CoS nanoparticles over G-CNFs (CoS/G-CNFs). The electrochemical studies such as cyclic voltammetry (CV), electrochemical impedance and Tafel polarization revealed that CoS/G-CNFs have lower overpotential, low charge transfer resistance and higher exchange current density for triiodide (I− 3 reduction reaction. The superior electrocat- alytic activity of CoS/G-CNFs than std. Pt is due to combined contribution of interconnected pore structure with high surface area of G-CNFs and excellent electrocatalytic activity of CoS. In addition, the dye sensitized solar cell (DSSC) based on platinum-free CoS/G-CNFs has exhibited higher photo-conversion efficiency (PCE) under a simulated solar light irradiation of 100 mW cm−2 when compared to standard platinum (std. Pt) which is attributed to the synergistic effect of CoS with G-CNFs.
采用简便的静电纺丝技术，以10 wt%的聚丙烯腈（PAN）在N，N -二甲基甲酰胺（DMF）中的溶液为前驱体，经过连续的稳定化、碳化和纯化过程，制备了一维石墨化碳纳米纤维（G - CNFs）。使用氯化钴和L - 半胱氨酸作为前驱体，通过水热法在G - CNFs上生长硫化钴（CoS）纳米颗粒。X射线衍射（XRD）和拉曼光谱的结果分别证实了相的形成和石墨化程度。场发射扫描电子显微镜（FE - SEM）和透射电子显微镜（TEM）图像证实了CoS纳米颗粒在G - CNFs（CoS/G - CNFs）上的形态、生长和分布。循环伏安法（CV）、电化学阻抗和塔菲尔极化等电化学研究表明，CoS/G - CNFs对于三碘化物（I₃⁻）还原反应具有更低的过电位、低电荷转移电阻和更高的交换电流密度。CoS/G - CNFs比标准Pt具有更优异的电催化活性，这归因于G - CNFs的高表面积相互连接的孔结构和CoS优异的电催化活性的综合贡献。此外，基于无铂CoS/G - CNFs的染料敏化太阳能电池（DSSC）在100 mW cm⁻²的模拟太阳光照射下，与标准铂（std. Pt）相比，表现出更高的光转换效率（PCE），这归因于CoS与G - CNFs的协同效应。
