Carbon-Nickel Oxide Nanocomposites - ResearchSpace

Carbon-Nickel Oxide Nanocomposites:

Preparation and charecterisation

Ngcali Tile^1,2, Kittessa Roro¹, Andrew Forbes^1,2

1 CSIR National Laser Centre, Pretoria

2 School of physics, university of KwaZulu-Natal, Durban

Energy delivery is still lacking in most rural Africa

Solar thermal technology is used for harnessing solar energy for water heating applications

Absorber material Reflective and thermally

conducting metal

0 200 400 600 800 1000 1200

0 0.2 0.4 0.6 0.8 1

1 10

Power density (W/m2 m) Ideal absorber reflectance

Wavelength (m)

Solar (AM1.5)

Blackbody Ideal selective absorber

100^oC 200^oC 300^oC

Spectrally selective surface have high solar absorptance accompanied by low thermal emittance



_sol 

I_sol

 





^{1 R}

 

^



^d

0.3 2.5



I_sol

 

 ^d

0.3 2.5



     

  



^

 ₂₀

5 . 2 20

5 . 2

1













d I

d R

I

P P

therm









   1  R

C-NiO

Aluminium substrate

C-NiO composite studied as a candidate spectrally selective material

G. Katumba et al. Sol.Energy Mater. Sol.Cells 92 (2008) 1285–1292

Absorbing

particles Host matrix

Samples were fabricated in 3 simple steps

Sol-gel technique can be adapted to different coating methods

coating

solution substrate

Spray coating Spin coating

air spray

Heat Coating NiO precursor

sol

(Nickel acetate +

Ethanol + DEA)

C precursor sol (SUCROSE SOLUTION)

Structure directing template (PEG)

Final C-NiO gel

By suitable choice of precursors, we can fabricate composite materials

Final C-NiO absorber Coating Al substrate

0 500 1000 1500 2000 2500 3000 0

50 100 150 200 250

1375.55 1585.58

Intensity (arb. units)

Raman shift (cm^-1)

EDS confirms NiO while Raman reveals a presence of predominantly graphite Carbon

Selectivity improves with an increase in heat treatment temperature

0 g 1 g

1.5 g 2 g

3 g 5 g

PEG affects the porosity of the films

Absorption properties vary with PEG content peaking at 2 grams

Summary of the most important results

Coating Cost/m² Lab scale

Cost/m² Large scale

C-NiO R 14.50 R 0.65

Solkote - R 12

Black Paint - R 4

Black Chrome - R 20

Nickel-Alumina - R 1.50

The cost of our coating is relatively cheap

Thank You