Janardhanan Jith C, Padmanabhan Nisha T, Jandas P J, Nayar Nabendu V, Manoj Narayanapillai, Pillai Suresh C, John Honey
Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi, Kerala 682022, India.
Inter University Centre for Nanomaterials and Devices, Cochin University of Science and Technology, Kochi, Kerala 682022, India.
J Colloid Interface Sci. 2023 Dec 15;652(Pt A):240-249. doi: 10.1016/j.jcis.2023.08.077. Epub 2023 Aug 11.
1D-molybdenum disulfide (MoS) nanoscrolls displayed enhanced electrochemical properties compared to 2D-MoS nanosheet counterparts. Rolling of nanosheets is the main fabrication route to nanoscrolls. However, owing to the conflict between chemical stability and multiple bending, the morphology transition from nanosheets to nanoscrolls is quite challenging. Herein we describe a reversible morphology transition from nanosheets to nanoscrolls by utilizing non-covalent interactions between MoS nanosheets and phenothiazine based organic dye. Interestingly, nanoscrolls can easily be opened back into nanosheets by destroying the non-covalent interactions with organic solvents. The prepared nanoscrolls exhibited enhanced electrochemical properties than nanosheets. Compared to nanosheets, nanoscrolls exhibited comparatively lower overpotential with a Tafel slope of 141 mV dec and high specific capacitance of 1868 F g. Hydrogen evolution by the Volmer-Heyrovsky mechanism being superior for the nanoscrolls is envisaged by the relatively increased availability of H sites at MoS edges induced by scrolling. Whereas the high specific capacitance value of nanoscrolls is ascribed to the enhanced electrical double-layer capacitance mediated charge storage, which arises due to the synergistic effect of both scrolled structure and the electron-rich phenothiazine-based dye.
与二维二硫化钼（MoS₂）纳米片相比，一维二硫化钼（MoS）纳米卷展现出增强的电化学性能。纳米片的卷曲是制备纳米卷的主要途径。然而，由于化学稳定性和多次弯曲之间的矛盾，从纳米片到纳米卷的形态转变颇具挑战。在此，我们描述了通过利用二硫化钼纳米片与吩噻嗪基有机染料之间的非共价相互作用，实现从纳米片到纳米卷的可逆形态转变。有趣的是，通过用有机溶剂破坏非共价相互作用，纳米卷可以很容易地重新展开成纳米片。所制备的纳米卷比纳米片表现出增强的电化学性能。与纳米片相比，纳米卷表现出相对较低的过电位，塔菲尔斜率为141 mV dec⁻¹，比电容高达1868 F g⁻¹。通过卷曲诱导的MoS边缘H位点可用性相对增加，推测纳米卷通过Volmer - Heyrovsky机制析氢更具优势。而纳米卷的高比电容值归因于增强的双电层电容介导的电荷存储，这是由卷曲结构和富电子的吩噻嗪基染料的协同效应引起的。
