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In situ studies on the effects of physisorption of various alcohol molecules (C n H 2n+1 OH; n = 1-4) on the transport properties of thin films of bundled single-walled carbon nanotubes reveal large increases in the thermoelectric power (TEP) S (∼1-4 µV K −1 ) and four-probe resistance R (∼4-8%) at 40 • C. Interestingly, exposure to water causes virtually no change in the TEP, although the electrical resistance shows a change of ∼4%, typical for the alcohols. We observe a simple exponential response of S(t) and R(t) to a sudden change in the molecular pressure. The characteristic time constants (τ ∼ 10 min) for S and R are found to be essentially the same for a given molecule, indicating that the changes in these transport properties track each other. In fact, plots of S versus R are linear, the slopes depending on the specific molecule. The transport results are interpreted in terms of a Boltzmann model and the introduction of a new scattering channel for charge carriers in metallic tubes due to weak interactions with physisorbed molecules. The trends in the changes in S and R with adsorption of these polar molecules can be explained on the basis of the interplay between the adsorption energy and the molecular coverage on the nanotube surfaces.

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Dumping of solid waste and draining of energy resources have become an escalating global issue by affecting the world’s ecology and economy through environmental pollution and fuel crisis. The primary concern of this investigation is to transform solid waste to clean energy conversion and storage material by developing a solid waste-derived carbon/metal oxide composite electrode for supercapacitors. For this purpose, we use infant-urinated waste diapers from the major municipality waste as a nitrogen-doped carbon source to develop a facile and cost-effective electrode material. The presence of urea/uric acid in the urinated diaper can contribute nitrogen atoms to carbon suitable for enhancing the electrical conductivity of the carbon electrode. NiO act as pseudocapacitor material for compensating the shortage of volumetric and gravimetric performance in carbon. The structural and chemical properties of solid waste-derived carbon fibers-trapped nickel oxides (NiO@SW-CFs) were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectrum (XPS), and nitrogen adsorption–desorption isotherms. Electrochemical studies on NiO@SW-CFs were performed using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. NiO@SW-CFs exhibited a specific capacitance of 356 F g–1 at a discharge current of 2 A g–1 with robust cycle stability after 5000 cycles with a current density of 10 A g–1. The synergic effect of NiO, N, and porous carbon proves NiO@SW-CFs as an excellent candidate for the future high-performance energy conversion and storage systems. This study offers a green approach for the development of environmentally favorable potential carbon electrodes, by converting solid waste to clean energy.