nano structured materials for hydrogen

8/8/2019 Nano Structured Materials for Hydrogen

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NANOSTRUCTURED MATERIALS

FOR HYDROGEN

PRODUCTION

PRESENTED BY:J.R.VAISHNAVI

A.ANUSUYA

III B.Tech

(Chemical Engg)

Kongu Engineering College, Erode


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FOREWORD

Energy carrier for the future national research priority

highest energy density of any non-nuclear fuel

can be easily converted to electrical andthermal energy

Fossil fuels like natural gas and crude oil are

obvious sources for the large quantities of

hydrogen needed to initiate the transition to a"Hydrogen Economy".


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BASIC PRINCIPLES OF TANDEM CELL

The Tandem Cell converts the energy of sunlight directlyinto hydrogen gas by splitting water into its constituentelements, Hydrogen and Oxygen.

Consists of two photo-catalytic cells in series

The front cell absorbs the high energy ultraviolet andblue light in sunlight, using nano-crystalline metal oxidethin films to generate electron-hole pairs.

The longer wavelength light in the green to red regionpasses through the front cell and is absorbed in a GraetzelCell producing electrical potential under nearly all lightconditions.


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Connected electrically and together provide thepotential required to split the water molecules in the

electrolyte.

The Cell is fabricated from widely-available and cheapmaterials.

The key to the cell is the performance of the metaloxides in reacting to the photons of the incident light.

The most expensive component of the Cells is currentlythe special glass, on which the nano-crystalline films aredeposited


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BLC approach for catalytic

nanocluster formation


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Flow diagram of the project


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CONSTRUCTION OF TANDEM CELL

This graphic shows schematically our Tandem Cell.

We have a front cell with glass walls containing awater-based electrolyte.

The photocatalytic nanocrystalline film is on therear wall of the cell on conducting glass. The high

energy UV and blue light is absorbed by the film.

Electrons are gathered and carried away andoxygen is formed.


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We use the red and green light which has passedstraight through in a second cell behind to the first.

Dye-solar cell (or Gratzel cell) but it could beformed from photovoltaic cells.

Boosts the energy of the electrons which thencome back to a hydrogen electrode in the front cell.

We would not make cells quite like this graphic, butif we did we would install a transparent membraneto separate hydrogen and oxygen, thus ensuringfuel cell grade hydrogen is produced.


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The Tandem Cell provides:

Hydrogen directly from sunlight and water

Approaching 7.5% efficiency

Renewable energy

No carbon or CO2 emissions

Using state of art technology -photo-catalysis

by nano-crystalline thin films Andmanufactured from low cost materials


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CHARACTERISATION

The adsorption of hydrogen in carbon nanotubeswill be followed using two different techniques:

X-ray spectroscopy and Temperature Desorption

Spectroscopy (TDS). The former will be used to study electronic

structure rearrangements. The latter will measure the strength of

adsorption (i.e. chemisorption, physisorption,and/or van der Waals interaction). The total amount of hydrogen can be calibrated

against hydrogen monolayer coverage on metalsurfaces.


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CONCLUSION Due to their large surface areas with relatively small

mass, SWCNTs have been considered as potentialmaterials for high capacity hydrogen storage.

There is currently much skepticism on carbon nanotubehydrogen storage due to early mistakes in experimentalpublications and therefore a rational basis for highcapacity hydrogen storage materials is being developed

through the systematic nano-materials researchundertaken in this effort.

Thus we can be able to produce and store hydrogen by

using nanomaterials and solar energy using Tandem cell

nano structured materials for hydrogen

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