Page 1

Functionalized carbon nanotubes for the removal of heavy toxic metals in nuclear industry T. SOMANATHAN Department of Nanoscience, School of Basic Sciences, Vels University, Chennai – 600 117, India Email: soma_nano@yahoo.co.in

INTRODUCTION  A high level of research activity has been concentrated on carbon nanotubes ever since the first report on the discovery by Sumio Iijima in 1991  Carbon nanotubes (CNTs), including single- and multi-walled structures, are an attractive class of nanomaterials.  Carbon nanotubes are recognised as potential candidates for future nanoscience and nanotechnology  CNTs become one of the most active fields of nanoscience and nanotechnology due to their exceptional properties.  Vertically-aligned CNTs (VACNTs) can provide a well-defined large surface area, and they can be readily incorporated into device configurations.

The catalytic route seems to be the most promising for large scale industrial applications, stemming from the relatively easy opportunity to upscale both the preparation and the purification method Catalysts having active catalytic centers are important for the large-scale production of CNTs using CVD method The metal particles plays an important role during CNT production and showing a direct correlation between the size of the metal nanoparticle and the eventual tube diameter The selection of the metallic catalyst may affect the growth and morphology of the nanotubes. The most common metals found to be successful in the growth of carbon nanotubes are Fe, Co, and Ni.

 CNTs could ensure better performances than activated carbon

 Open ended CNTs is the ability to encapsulate substances

a variety of

 water purification technology is often complicated, requires sophisticated equipment and is expensive to run and maintain

 Toxic trace elements such as arsenic, cadmium, lead, copper, nickel, zinc, chromium and viscous liquid impurities such as oil can be removed using nanotechnology.

 Vertically-aligned carbon nanotubes possess many advantages for a wide range of multifunctional applications.

Catalytic synthesis of carbon nanotubes by CVD method Furnace Catalyst Inert gas Preheat temperature Carbon Sources Reaction temperature

Synthesis of FeMoMgO Catalyst

: Horizontal furnace : FeMoMgO catalyst : Argon : RT – 550 0C : Acetylene : 550 0C

EXPERIMENTAL SETUP Alumina boat catalyst + CNTs

Gas Inlet The synthesis of catalysts started with dissolving salts of Fe(NO3)3, Mg(NO3)2.6H2O and (NH4)6Mo7O24.4H2O, respectively in distilled water. The solutions were mixed together with citric acid as a combustion fuel. The mixture was directly fed into the furnace and fired at 550 °C for 5 min. After the combustion process, the produced foaming materials were grounded into fine powder using a mortar

Gas outlet

Horizontal Furnace Trap

Hata et al, Science 306 (2004) 1362 Ar

Characterisation of catalytic materials

C2H2

Characterisation of Carbon nanotubes SEM

XRD

H2

Conclusion

TEM

SEM

Intensity (a.u.)

 From this study, it can be concluded that FeMoMgO catalytic material is an effective catalyst for the production of CNTs.  We have found that MgO exhibits a better metal support interaction,leading to the selective synthesis of vertical aligned carbon nanotubes in a short time scale.

40

60

80

Raman spectrum

2 theta (degree)

This method is economical and offers advantages such as low synthesis temperature, simplicity, high graphitization with high yield.

Intensity (a.u.)

20

Raman Shift (cm-1)

Acknowledgement The author would like to thanks to Vels University, Chennai, India, for providing infra structure facilities

P007  

nanotechnology

Read more
Read more
Similar to
Popular now
Just for you