Carbon Nanotubes in Wastewater Remediation

Carbon nanotubes (CNT) are a family of carbon nanomaterials that have uses in many technological and medical applications due to their unique properties. However, compared to other nanomaterials, CNT have a significantly lower specific surface areas (SSA), which is a critical limitation for applications. To overcome this limitation, here, we report a new protocol to synthesize a hybrid material composed of varying ratios of multiwalled carbon nanotubes (MWCNT) and ferrihydrite (FHY). Furthermore, through a series of physical and electrochemical characterization tests, we determined that 36% FHY and 64% MWCNT is the optimum ratio for a composite that maximizes both SSA and specific capacitance. The calculated SSA of the composite was 190 m2·g−1, 2.9 times higher than that of MWCNT alone. Moreover, the composite retained valuable electrochemical properties of CNT with an estimated specific capacitance of 100 F·g−1. This composite is a promising multifunctional nanomaterial for environmental and technological applications requiring electrochemical reactivity and high specific areas such as environmental biosensors, and capacitive deionization for wastewater remediation, and water softening.

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Structural phenomena in the growth of carbon nanotubes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149581 ◽

1993 ◽

Vol 51 ◽

pp. 750-751

Author(s):

Jun Jiao

Keyword(s):

Carbon Nanotubes ◽

Growth Mechanism ◽

Carbonaceous Material ◽

Cluster Growth ◽

Structural Elements ◽

Rich Variety ◽

Different Shapes ◽

Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

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