Nanotechnology shows promise for protecting the environment in several ways: 1. Nanoparticles can be used to make more efficient solar cells, wind turbine blades, and batteries to help transition to renewable energy. 2. Nanomaterials have properties that allow for more effective water treatment, such as through filtration and photocalytic disinfection. 3. Nanocatalysts can help reduce pollution by enabling more effective catalytic converters and chemical production processes. However, there is still uncertainty around the environmental impacts of nanomaterials. Their large surface area means nanoparticles could interact with the environment in unexpected ways, and some core nanomaterials are toxic. More research is needed to evaluate risks and ensure nanotechnologies are developed and managed

2. From lakes to oceans, from air to soil,
from forests to deserts, from farms
to cities.
How can small science help us protect
such a big beautiful world?

3. Nanotechnology and
Environment
• Nanotechnology is making significant
improvements in technologies for
protecting the environment
• Someday we may be able to prevent
pollution with the help of
nanotechnology.
• On the other hand, nanotechnology's
unique characteristics may also lead to
unforeseen environmental problems.

4. Why Nano?
 High surface area of Nanomaterials
 Durability against mechanical stress or weathering
 Nanotechnology-based dirt- and water-resistant coatings
reduce cleaning efforts
 Adding nanoparticles reduces weight and saves energy during
transport
 Nanomaterials can boost energy and resource efficiency based
on their special catalytic properties

5. Solar Cells
• Researchers have demonstrated that an
array of silicon nanowires embedded in a
polymer results in low cost but high
efficiency solar cells
• Less amount of materials are required in
these solar cells
• Nanomaterials can be used to increase the
energy storage capacity of Lithium-ion
batteries
• Self-cleaning glass cover increases the
efficiency of solar cells indirectly

6. Wind Mills
 Epoxy containing carbon nanotubes is being used
to make wind mill blades.
 The resulting blades are stronger and have lower
weight
 Therefore the amount of electricity generated by
each windmill is greater.

7.  Using graphene layers to increase the binding energy of
hydrogen to the graphene surface in a fuel tank results in
a higher amount of hydrogen storage and a lighter weight
fuel tank.
 This could help in the development of practical hydrogen-
fueled cars.
Hydrogen powered Vehicles

8.  Researchers have managed to recover pure zinc oxide
nanoparticles from spent Zn-MnO2 alkaline batteries.
Battery Recycling

9.  Photocatalytic copper tungsten oxide
nanoparticles break down oil into
biodegradable compounds
 Nanoparticles are a grid that provides high
surface area
 Activated by sunlight and can work in water
Oil Spillage

10. Radioactive Waste Clean-up
 Unique structural properties of titanate nanotubes and
nanofibers make them superior materials for removal of
radioactive cesium and iodine ions in water.

12. Nanotechnology in Water
Treatment
 Sensing and Detection
 Treatment and Remediation
 Pollution Prevention

13.  For Nanofiltration:
 Carbon Nanotubes and alumina
fibres
 Nanoscopic pores in zeolite filtration
membranes
 Nanocatalysts and magnetic
nanoparticles
 For Analytical Detection:
 Nanosensors based on Titanium
Oxide nanowires or palladium
nanoparticles
 For Treatment and Remediation:
 Enhanced reactivity, surface area
and sequestration characteristics
 Increased affinity, capacity and
selectivity for heavy metals and
other contaminants

14.  Nanoporous membranes can allow for fast convective water flow
across well-defined channels
 The pores can be formed by knocking out carbon atoms out of
Graphene with the help of Oxygen plasma.
 Optimum pore size for effective desalinization = 0.5-1
nanometres
Nanotechnology in Desalinization

15.  Bioactive nanoparticles for water
disinfection:
 Can replace chlorine
 Metalliic and metal-oxide
nanoparticles, especially silver and
titanium dioxide can be used for
photocatalytic disinfections

16.  Nanotechnology can clean arsenic contaminated drinking water
cheaply and simply enough to use in developing countries
 Researchers have developed nanocrystalline photocatalysts
that purify water by accelerating a reaction that requires light
 Nanoparticles use sunlight to break down organic pollutants,
such as those in the oil industry
 The nanocrystals demonstrate an improved performance as
well as the ability to recover them
 Researchers have shown that iron nanoparticles can be
effective in cleaning up organic solvents that pollute
groundwater
Cleaner Water with
Nanotechnology

17.  Nanotechnology can be
utilized to clean up toxic
waste sites. Researchers
have developed sponge-
like nanoporous materials
that can mop up pollutants
in air and water, and break
down noxious wastes
therefore reducing
greenhouse gases.
Toxic Waste Cleanup

18. Nanochemicals and Nanocatalysts
Nanochemicals and nanocatalysts can be used to purify exhaust
Silver nanocrystals as catalysts can significantly
reduce the polluting byproducts generated in
the manufacture of propylene oxide
Gold particles less than 6nm in size
become active catalysts, helping
oxygen combine with carbon
monoxide to make carbon dioxide.

19.  Hydrogen- a clean energy source
 Artificial photosynthesis, using solar energy to split water
generating hydrogen and oxygen, can offer a clean and
portable source of energy supply as durable as the sunlight
 Inorganic light harvesting nanocrystal array can be combined
with a low-cost electrocatalyst that contains abundant
elements to fabricate an inexpensive and stable system for
photoelectrochemical hydrogen production
Artificial Photosynthesis

20. So, Isn’t This Great
News?
1. Nanoparticles in nature can be used to
clean up polluted environments by
weakening pollutants and hazardous
organisms in the ground, air or water
2. Pipes might be coated with
nanoparticles to weaken pollutants as
they pass through
3. Nanoparticles could also monitor
biochemical threats which would
increase public safety
4. Nanomaterials can be used to conserve
energy

21. What might happen to the environment if they get out of
control? They could cause unexpected and dangerous
reactions in plants, animals or the environment.
What is the cost to the environment when we manufacture
and use these nanomaterials and techniques?
But…

22. Why Do Nanoparticles Have
a Greater Impact?
The amount of surface area
of a substance affects the
interaction of chemicals in
that substance with the
environment. Smaller
particles, nanoparticles,
would result in a great deal of
surface area. Thus there will
be a dramatic increase in the
interaction between that
substance and the
environment if its particle
size changes from macro
to micro to nano!

23. Environmental Factors
 A second concern
is that some core
materials of the
nanoparticles can
be toxic to the
environment.

24.  Nanoparticles are often
coated with a different
material than the core.
These coatings are
expected to interact with
the environment. But the
core material may
become exposed to the
environment when the
coating is worn away.
 For example, microscopic
organisms, such as
daphnia in water, digest
the coating and expel the
core material back into
the environment.

25.  Lastly, the environment
itself affects the toxicity and
fate of the nanoparticles.
 Soil, water or particles in the
air can interact with
nanoparticles and affect
what these particles
become and where they
eventually end up.

26. Why Nanotechnology
Then??
 Technological advances which benefit
and protect the environment are one
reason to invest in nanotechnology
research related to the environment.
 A second reason to invest in nano-
environmental research is because of
the potential impact of nanoparticles
in the environment.

27. Evaluation Needed
Three main areas of nanoscience in the environment need to
be researched to evaluate the impact of nanoparticles:
1. The appropriateness and effectiveness of
present plans to identify and manage
nanomaterials which have the greatest risk
to the environment.
2. Evaluate our ability to minimize hazards
and exposure to high-risk nanoparticles.
3. Evaluate present risk management plans
for all nanomaterials.

28. THANK YOU….