Few-layer MoS2 nanosheets coated onto multi-walled carbon nanotubes as a low-cost and highly electrocatalytic counter electrode for dye-sensitized solar cells
Few-layer MoS2 nanosheets coated onto multi-walled carbon nanotubes as a low-cost and highly electrocatalytic counter electrode for dye-sensitized solar cells
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DOI：
10.1039/c2jm35447k
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发表时间：
2012-11
影响因子：
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通讯作者：
Sheng-Yen Tai;Chia-Jui Liu;S. Chou;F. Chien;Jeng-Yu Lin;Tsungwu Lin
中科院分区：
文献类型：
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作者：
Sheng-Yen Tai;Chia-Jui Liu;S. Chou;F. Chien;Jeng-Yu Lin;Tsungwu Lin
在目前的研究中，二硫化钼和多壁碳纳米管（MWCNT@MoS2）的纳米复合材料首次被提出作为染料敏化太阳能电池（DSSC）中的对电极（CE）催化剂，以加速三碘（I3−）还原为碘（I−）。这种新型催化剂的合成是通过在酸性溶液中简单地混合MWCNT和MoS 2，然后在650 °C的H2气流中将固体中间体转化为MWCNT@MoS2纳米复合材料。X射线粉末衍射、拉曼光谱和X射线光电子能谱证实了MWCNT@MoS2纳米复合材料的组成和结构。通过透射电子显微镜研究了纳米复合材料的微观结构细节，表明在MWCNT表面上仅形成了几层MoS 2纳米片。这种独特的结构有利于提高MWCNT@MoS2对I3-还原的催化活性。广泛的循环伏安（CV）表明，MWCNT@MoS2 CE的阴极电流密度高于MoS 2、MWCNT和溅射Pt CE的阴极电流密度，这是由于前者的活性表面积增加。此外，MWCNT@MoS2 CE的峰值电流密度在连续100 CV测试后没有显示出降解的迹象，表明MWCNT@MoS2 CE具有很好的电化学稳定性。此外，MWCNT@MoS2 CE在I3−还原方面表现出令人印象深刻的低电荷转移电阻（1.69 Ω cm 2）。最后，用MWCNT@MoS2 CE组装的DSSC显示出6.45%的高功率转换效率，这与用Pt CE组装的DSSC（6.41%）相当。
In the current study, the nanocomposite of molybdenum disulfide and multi-walled carbon nanotubes (MWCNT@MoS2) was proposed for the first time as a counter electrode (CE) catalyst in dye-sensitized solar cells (DSSCs) to speed up the reduction of triiodide (I3−) to iodide (I−). This novel catalyst was synthesized by simply mixing MWCNTs and MoS2 in an acidic solution and then converting the solid intermediate into the MWCNT@MoS2 nanocomposite in a H2 flow at 650 °C. X-ray powder diffraction, Raman and X-ray photoemission spectroscopy confirmed the composition and the structure of the MWCNT@MoS2 nanocomposite. The microstructure details of the nanocomposite were studied by transmission electron microscopy, showing that only a few-layers of the MoS2 nanosheets were formed on the MWCNT surface. This unique structure is beneficial to the improvement of the catalytic activity of MWCNT@MoS2 towards the reduction of I3−. The extensive cyclic voltammograms (CV) showed that the cathodic current density of the MWCNT@MoS2 CE was higher than those of MoS2, MWCNT and sputtered Pt CEs due to the increased active surface area of the former. Moreover, the peak current densities of the MWCNT@MoS2 CE showed no sign of degradation after consecutive 100 CV tests, suggesting the great electrochemical stability of the MWCNT@MoS2 CE. Furthermore, the MWCNT@MoS2 CE demonstrated an impressive low charge-transfer resistance (1.69 Ω cm2) for I3− reduction. Finally, the DSSC assembled with the MWCNT@MoS2 CE showed a high power conversion efficiency of 6.45%, which is comparable to the DSSC with Pt CE (6.41%).