R. Subash prepared graphitic carbon nitride (g-C3N4) and bismuth vanadate (BiVO4) using different synthesis methods and characterized their properties. g-C3N4 nanosheets and bulk g-C3N4 were synthesized via calcination, while BiVO4 nanorods were prepared using a hydrothermal method. Various g-C3N4/BiVO4 hybrid materials with different weight percentages were also synthesized hydrothermally. The materials were characterized using UV-vis spectroscopy, XRD, FT-IR and FE-SEM to analyze their optical, crystalline and morphological properties. The bandgaps of the hybrid materials decreased with increasing g-C3N4

1. Synthesis and Characterization of Graphitic
Carbon Nitride-Bismuth Vanadate Hybrid
Materials
DONE BY;
R.SUBASH
PROJECT STUDENT
PSG COLLEGE OF ARTS AND SCIENCE
COIMBATORE
Supervisor
Dr. A. Pandikumar
Scientist,
Functional Materials Division,
CSIR-CECRI.
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2. PHOTOCATALYSIS
Photocatalysis is the acceleration of a photoreaction in the presence of
a catalyst.
Photocatalysis is a reaction which uses light to activate a substance which
modifies the rate of a chemical reaction without being involved itself.
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3. Journal of Photochemistry and Photobiology C:
Photochemistry Reviews 13 (2012) 169–189
Applications of TiO2 photocatalysis
Limitation of TiO2
Wide band-gap
Active under UV light
Poor charge transfer process
High recombination‘s
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4. Alternative Materials for
photocatalysis
 Metal oxides
 Carbon based Materials
Plasmonic photocatalysts
 Metal halides
 Metal sulphides
( ZnO,BiVO4, Bi2WO6 )
( ZnS,CdS,)
( carbon nanotube,graphitic materials
and graphene based materials )
( AgX,BiX)
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(Ag-TiO2 )

5. Graphitic Carbon Nitride
 It is a metal free semiconductor photocatalysis
 These catalysts are having appealing electronic structure
 Moderate band gap
 High physicochemical stability
 Excellent absorption in visible region
 Low cost
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6. g-C3N4 Structure
 Tri-s-triazine is the most stable allotrope among various carbon nitride under
ambient condition.
It is two-dimensional frameworks of tri-s-triazine connected via tertiary amines
Triazine (left) and tri-s-triazine (right) structures of g-C3N4 allotropes
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7. PROPERTIES OF G-C3N4
 High thermal and chemical stability
 Metal free photocatalyst
 Band gap value is 2.7 eV
 absorption in visible region
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8. Possible synthesis routes 8

9. Applications 9

10. BiVO4 structure
It existed in 3 crystalline structures
 Monoclinic scheelite
 Tetragonal zircon
 scheelite
Monoclinic scheelite structure has high photocatalytic activity because of its narrow band
gap (2.34 eV)
Band gap of tetrahedral zircon is 3.31 eV
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11. Properties
 Non toxic
 High photocatalytic activity
 Pure BiVO4 has high electron hole recombination
 absorption in visible region
 It is a yellow pigment
 Band gap value is 2.4 eV
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12. Applications
 Degradation of organic pollutants
 Decomposition of water
 Evolution of O2
 Reduction of CO2
 Photogenerated current
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13. g-C3N4/BiVO4 Hybrid Catalyst
g-C3N4
h+
h+
e-
e-
e-
E
bg
=
2.7
eV
E
bg
=
2.4
eV
H2O
.OH
Pollutant
Product
O2
.O2
-
Pollutant
Product
BiVO4
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14. Objectives
 To prepare g-C3N4 calcination method
 To prepare BiVO4 nanorods by hydrothermal method
 To prepare g-C3N4 NSs-BiVo4 hybrid material by hydrothermal method
 Characterization to obtain the physicochemical and morphological study for the
above materials
To utilize this above materials for photocatalytic dye degradation
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15. Preparation of g-C3N4 bulk
melamine
Calcination at 600c ( at the rate of 2c/minute)
In box furnace
G-C3N4 bulk
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16. Preparation of g-C3N4 nanosheets
Melamine
(2 g)
Ammonium sulphate
(2 g)
Homogeneous mixing
In mortar
Calcination at 600c ( at the rate of 2c/minute)
In box furnace
G-C3N4 nanosheets
1:1 ratio
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17. Preparation of BiVO4 nanorods
Bismuth nitrate pentahydrate
(Bi(NO3)3 .5H2O) (0.970 g)
sodium oleate (4g)
Dissolved in 35 ml of ethylene
glycol
Ammonium meta vanadate solution (0.234 g of
NH4VO3 in 5 ml of water)
Stirring for 2 hours
Orange emulsion transferred to autoclave
180c for 24 hours
centrifugation
60c for 10
hours
BiVO4 Nanorods
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18. Preparation of g-C3N4/BiVO4 hybrid
material
sodium oleate (4g)
g-C3N4
NSs
Dissolved in 35 ml of ethylene
glycol
Ammonium meta vanadate solution
(0.234 g of NH4VO3 in 5 ml of water)
Stirring for 2 hours
Orange emulsion transferred to autoclave
180c for 24 hours
centrifugation
60c for 10
hours
g-C3N4/BiVO4
hybrid material
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19. Characterisation studies
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20. Absorption Spectral Property
Materials l (nm)
Bulk g-C3N4 468 nm
g-C3N4 NSs 496 nm
BiVO4-g-
C3N4NSs
537 nm
BiVO4 514 nm
Materials
l (nm)
BiVO4-g-C3N4 NSs (10 wt%)
537 nm
BiVO4-g-C3N4 NSs (6 wt%)
532 nm
BiVO4-g-C3N4 NSs (3 wt%)
529 nm
BiVO4-g-C3N4 NSs (1 wt%)
528 nm
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21. Tauc’s Plots for band-gap Calculation
Materials Ebg (eV)
Bulk g-C3N4 2.65ev
g-C3N4 NSs 2.5eV
BiVO4-g-C3N4 NSs 2.31eV
BiVO4 2.41eV
Materials Ebg (eV)
BiVO4-g-C3N4 NSs (1 wt%) 2.35eV
BiVO4-g-C3N4 NSs (3 wt%) 2.34eV
BiVO4-g-C3N4 NSs (6 wt%) 2.33eV
BiVO4-g-C3N4 NSs (10 wt%) 2.31eV
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22. X-Ray Diffraction Patterns Studies
Materials JCPDS Card No.
Bulk g-C3N4 87-1526
g-C3N4 NSs 87-1526
BiVO4-g-C3N4 NSs 00-044-0081
BiVO4 83-1699
Debye–Scherrer equation
D = Kλ/β cos θ
Where
D - crystal size of the catalyst,
λ - X-ray wavelength (0.154 nm)
β - full width half maximum of the catalyst
K = 0.89
θ - diffraction angle.
Crystal Size
Materials Size (nm)
Bulk g-C3N4 8.5 nm
g-C3N4 NSs 7.7 nm
BiVO4-g-C3N4 NSs(10wt%) 33.0 nm
BiVO4 26.6 nm
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23. X-Ray Diffraction Patterns Studies
Materials Size (nm)
BiVO4-g-C3N4 NSs (1 wt%) 28.2 nm
BiVO4-g-C3N4 NSs (3 wt%) 32.2 nm
BiVO4-g-C3N4 NSs (6 wt%) 33.8 nm
BiVO4-g-C3N4 NSs (10 wt%) 33.8 nm
Materials JCPDS Card No.
BiVO4-g-C3N4 NSs (10 wt%) 00-044-0081
BiVO4-g-C3N4 NSs (6 wt%) 00-044-081
BiVO4-g-C3N4 NSs (3 wt%) 00-044-081
BiVO4-g-C3N4 NSs (1 wt%) 00-044-081
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24. FT-IR SPECTRAL
PROPERTIES
The spectrum of the g-C3N4 nanosheet shows broad bands of the stretching and
deformation modes of -NH2 groups at 3342 and 3469 cm-1. The peaks at 801 and 1470
cm-1 belong to the s-triazine ring modes. The band at 1645 cm-1 was attributable to C=N
stretching vibration modes, while the peaks at 1247, 1324 and 1414 cm-1 were related to
aromatic C-N stretching. FT-IR spectra of the Pure BiVO4 has a broad band between 650
and 850 cm-1, which is attributed to Bi-O and V–O vibrations.
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25. FE-SEM & EDAX Analysis
BiVO4 g-C3N4-BiVO4
g-C3N4
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BiVO4-g-C3N4 NSs
BiVO4 g-C3N4 NSs

26. Summary & Future Work
 g-C3N4 bulk and g-C3N4NSs were prepared
 Pure BiVO4 and g-C3N4/BiVO4 hybrid materials were prepared for different wt.%
 Optical property of the materials is obtained by diffused reflectance spectroscopic studies
 Bonding modes of the materials were obtained by FT-IR spectral studies
 Crystalline properties of hybrid materials were obtained by XRD
 Morphologies of the materials were obtained from FE-SEM
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Evaluation of photocatalytic performance of hybrid materials will be studied
Towards degradation of Rh-B.

27. Acknowledgements
Dr.M.Sathish, Scientist, FMD for providing necessary instrumentation facility
Dr. K. Lakshminarasimhan, Senior Scientist, FMD for providing Centrifuge machine facility.
Dr. P.Murugan, Senior Scientist and all FMD Scholars for support and encouragement.
Dr.A.Pandikumar, scientist, FMD for guiding me throughout this project
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