Photocatalysis-Movie

Photocatalysis : 

Photocatalysis Synthesis of TiO2 Nanotubes and It’s Applications By Rakesh Sadu

Slide 2: 

The photocatalytic activity of nano-titanium dioxide (TiO2) has been utilized to significantly improve the degradation efficiencies of various contaminants in both water treatment and air pollution control. Depends on: Wavelength of Light Surface Area of Catalyst Catalysis under light irradiation, called Photocatalysis. Photocatalysis

Slide 3: 

e- + hν Chemistry O2 e- + e- + O2 O2 O2- O2- O2- H2O H2O H2O e- e- e- OH OH OH Conduction Band (CB) Valence Band (VB) e−cb h+vb Excite e- Recombination Photon (hν) Physics and chemistry of photocatalytic titanium dioxide: Visualization of bactericidal activity using atomic force microscopyS. Banerjee1,3,*, Judy Gopal2, P. Muraleedharan2, A. K. Tyagi1 and Baldev Raj1

Titania : 

Titania 22 47.9 Ti [Ar] 3d2 4s2 Tetragonal; a = 3.79 nm, b = 3.79 nm, c = 2.38 nm. TiO2 There are three types of crystal structure in TiO2: anatase, (2) rutile and (3) brookite. Band Gap: Anatase ~ 3.2 eV Rutile ~ 3.02 eV Brookite ~ 2.96 eV Thus, light of wavelength λ < 411 nm, will excite e– from the valence band to the conduction band, producing an e––h+ pair Physics and chemistry of photocatalytic titanium dioxide: Visualization of bactericidal activity using atomic force microscopyS. Banerjee1,3,*, Judy Gopal2, P. Muraleedharan2, A. K. Tyagi1 and Baldev Raj1 Simple Method of Measuring the Band Gap Energy Value of TiO2 in the Powder Form using a UV/Vis/ NIR Spectrometer a b c

Titanium Nanotubes (TNTs) : 

Titanium Nanotubes (TNTs) TiO2 Powder Treatment with 10M NaOH Treatment with DW Treatment with HCl(aq) Treatment with DW TiO2 Nanotubes Formation of titanium oxide nanotubes using chemical treatments and their characteristic properties by Tomoko Kasuga * Hydrothermal Method

TNTs Characterization : 

TNTs Characterization Adsorption behavior of arsenic onto protonated titanate nanotubes prepared via hydrothermal methodH.Y. Niu a, J.M. Wang a, Y.L. Shi a, Y.Q. Cai a,*, F.S. Wei b,* TP 15 m2/g 30–50 nm ED TNTs-110 197.05 m2/g, 5nm ED, 2-3nm ID >100nm TNTs-180 312.59 m2/g, 13nm ED, 4.5-5.5nm ID >150nm ___ 50nm ___ 15nm ___ 10nm

TNTs FormationMechanism : 

Ti O Shorter Ti-O Bond 0.1934nm Longer Ti-O Bond 0.1980nm OH Na TNTs FormationMechanism S. Zhang, W. Li, Z. Jin, J. Yang, J. Zhang, Z. Du, Z. Zhang, Study on ESR and inter-related properties of vacumm-dehydrated nanotube titanic acid, J. Solid State Chem. 11 (2004) 1365–1371. Ti-O-Na Ti-OH

Slide 8: 

Na+ O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- Na+ Na+ O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- Na+ O- OH- Ti Na+ O- Na+ 2 TiO2 + 2 NaOH  Na2Ti2O4(OH)2 J. Yang, Z. Jin, X. Wang, W. Li, J. Zhang, S. Zhang, X. Guo, Z. Zhang, Study on composition, structure and formation process of nanotubeNa2Ti2O4(OH)2,DaltonTrans.(2003)3898–3901.

Slide 9: 

H+ O- OH- Ti H+ O- H+ O- OH- Ti H+ O- H+ O- OH- Ti H+ O- O- OH- Ti H+ O- H+ O- OH- Ti H+ O- H+ O- OH- Ti H+ O- H+ H+ O- OH- Ti H+ O- H+ O- OH- Ti H+ O- H+ O- OH- Ti H+ O- O- OH- Ti H+ O- H+ O- OH- Ti H+ O- H+ O- OH- Ti H+ O- H+ Na2Ti2O4(OH)2 + HCl  H2Ti2O4(OH)2 2 TiO2 + 2 NaOH  Na2Ti2O4(OH)2 J. Yang, Z. Jin, X. Wang, W. Li, J. Zhang, S. Zhang, X. Guo, Z. Zhang, Study on composition, structure and formation process of nanotubeNa2Ti2O4(OH)2,DaltonTrans.(2003)3898–3901.

Applications : 

Applications Self-sterilizing photocatalytic tiles Anti-fogging glass Self cleaning tunnel lighting fixtures Film for automobile side-view mirrors Self-cleaning, self-sterilizing paper clothing Car air purification Road-side Pavements Water Purification

Arsenic Removal with TNTs : 

Arsenic Removal with TNTs Arsenic, a common constituent of the earth’s crust, has been the concern of the world for many years for its high toxicity and carcinogenicity. NaAsO2 6000ppb TNTs 0.2 gm/lt EPA has set the arsenic standard for drinking water at 10 parts per billion. A glass reactor covered with photo-inhibitor Experimental Setup : Observed the Adsorption behavior in the DARK Nano-Band Explorer Trace Metals Analysis System http://dept.lamar.edu/engineering/COE/MIC/electrochemical_analysis.html Testing photo-oxidation of As (UV < 385 nm)

Adsorption vs. Time : 

Adsorption vs. Time 90 80 70 60 50 40 30 20 10 0 100 AsIII+ 180 TN AsIII+ 110 TN 1 2 3 4 5 6 8 9 10 20 22 24 84% 76% Percent Adsorbed Time

Conclusion : 

Conclusion Photocatalysis and photo-chemistry of TiO2 are discussed. Hydrothermal TNTs have been demonstrated with formation mechanism and its applications. 83% of AsIII+ adsorbed over 180-TNTs surface within 1 hr.

Future Work : 

Future Work Photo-oxidation of Asiii+ to Asv+ over TNTs. Nb2O5 Nanotubes for water splitting Recycling of the Catalyst. Uniformity – length and size of TNTs. TNTs for removal of Atrazine, Rhodamine-B etc. Doping.

Thank You : 

Thank You Any Mr. (or) Ms. Q ?