Huang Shoushuang, He Qingquan, Chen Wenlong, Qiao Qiquan, Zai Jiantao, Qian Xuefeng
Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240 (P. R. China).
Chemistry. 2015 Mar 2;21(10):4085-91. doi: 10.1002/chem.201406124. Epub 2015 Jan 29.
Two-dimensional (2D) semiconducting nanosheets have emerged as an important field of materials, owing to their unique properties and potential applications in areas ranging from electronics to catalysis. However, the controlled synthesis of ultrathin 2D nanosheets remains a great challenge, due to the lack of an intrinsic driving force for anisotropic growth. High-quality ultrathin 2D FeSe2 nanosheets with average thickness below 7 nm have been synthesized on large scale by a facile solution method, and a formation mechanism has been proposed. Due to their favorable structural features, the as-synthesized ultrathin FeSe2 nanosheets exhibit excellent electrocatalytic activity for the reduction of triiodide to iodide and low charge-transfer resistance at the electrolyte-electrode interface in dye-sensitized solar cells (DSSCs). The DSSCs with FeSe2 nanosheets as counter electrode material achieve a high power conversion efficiency of 7.53% under a simulated solar illumination of 100 mW cm(-2) (AM 1.5), which is comparable with that of Pt-based devices (7.47%).
二维（2D）半导体纳米片因其独特的性质以及在从电子学到催化等领域的潜在应用，已成为材料领域的一个重要方向。然而，由于缺乏各向异性生长的内在驱动力，超薄二维纳米片的可控合成仍然是一个巨大的挑战。通过一种简便的溶液法已大规模合成了平均厚度低于7 nm的高质量超薄二维FeSe₂纳米片，并提出了其形成机理。由于其良好的结构特性，所合成的超薄FeSe₂纳米片在将三碘化物还原为碘化物方面表现出优异的电催化活性，并且在染料敏化太阳能电池（DSSC）的电解质 - 电极界面具有低电荷转移电阻。以FeSe₂纳米片作为对电极材料的DSSC在100 mW cm⁻²（AM 1.5）的模拟太阳光照下实现了7.53%的高功率转换效率，这与基于Pt的器件（7.47%）相当。
