Bo co tiu lun

QUANG XC TC NANO TITAN OXIDE

CBGD: PGS. TS. NGUYN NGC HNH HVTH: NGUYN THANH THO UYN MSHV: 11054193
THNG 11/2012

NI DUNG BO CO
1. TNG QUAN Vt liu titan oxide (TiO2) Phn ng quang xc tc 2. NG DNG Oxy ha cc hp cht hu c Oxy ha cht kh 3. KT LUN

1. TNG QUAN c im vt liu TiO2

Khng t tin; Cht oxy ha mnh; Khng c hi; Bn quang.

1. TNG QUAN Cu trc vt liu TiO2

a) Anatase

b) Rutile

c) Brookite

Hnh 1. Cu trc tinh th TiO2

4

1. TNG QUAN Cu trc vt liu TiO2

Rutile

Anatase

Hnh 2: Gc bt din trong cu trc tinh th TiO2

5

1. TNG QUAN Cu trc vt liu TiO2

Bng 1: T khi v nng lng vng cm TiO2 Rutile T khi (g/cm3) Ebangap (eV) 4,250 3,1 Anatase 3,894 3,2

1. TNG QUAN Quang xc tc Qu trnh quang xc tc l mt trong nhng qu trnh oxy ha nng cao nh tc nhn nh sng. Advanced Oxidation Process (AOP)

1. TNG QUAN Quang xc tc Qu trnh oxy ha nng cao c nh ngha l nhng qu trnh phn hy oxy ha da vo gc t do hot ng hydroxyl *OH c to ra in situ ngay trong cc qu trnh x l.

1. TNG QUAN Quang xc tc

Zhou, H. and Smith, D.H., 2001

9

1. TNG QUAN Quang xc tc

US EPA, 1998; US EPA. 2001

10

1. TNG QUAN Quang xc tc

11

1. TNG QUAN C ch hnh thnh gc t do hydroxyl *OH

Vng dn (CB) e-CB + O2 *O2- (Gc ion superoxit)
2*O2- + 2H2O H2O2 + 2OH- + O2
e-

H2O2 + e-CB *OH + OH-

- electron + hole
eeeeee-

Band gap TiO2 3,2 eV

h+VB + H2O *OH + H+ h+VB + -OH *OH

e-

e-

e-

e-

e-

e-

e-

e-

e-

e-

e-

e-

Vng ha tr (VB)
12

1. TNG QUAN C ch v phng thc phn ng ca *OH Gc hydroxyl *OH c th tc kch vi cc cht nhim theo cc kiu sau y: i) Phn ng cng vi cc hp cht khng no dy thng hoc vng thm, to ra gc mi hydroxylat hot ng: *OH + CH2=CH2 *CH2-CH2(OH)

13

1. TNG QUAN C ch v phng thc phn ng ca *OH Gc hydroxyl *OH c th tc kch vi cc cht nhim theo cc kiu sau y: ii) Phn ng tch hydrogen t cc hp cht no hoc khng no, to thnh nc v gc mi hot ng: *OH + CH3-CO-CH3 *CH2COCH3 + H2O

14

1. TNG QUAN C ch v phng thc phn ng ca *OH Gc hydroxyl *OH c th tc kch vi cc cht nhim theo cc kiu sau y: iii) Phn ng trao i in t to ra gc ion mi hot ng: *OH + CH3-S-C6H5 [CH3-S-C6H5]+* + OH-

15

1. TNG QUAN C ch v phng thc phn ng ca *OH Qu trnh phn ng tip tc pht trin nh cc gc t do mi sinh ra theo kiu phn ng dy chui cho n khi v c ha (khong ha) hon ton hoc dy chui b t.

16

2. NG DNG

17

2. NG DNG Oxy ha cc hp cht hu c

18

2. NG DNG Oxy ha cc cht mu Dt nhum v ngnh cng nghip thuc nhum to nn phn ln cc hp cht hu c nguy hi i vi mi trng. Khong 1 20% tng lng thuc nhum thot ra trong sut qu trnh nhum v gii phng ra mi trng. Gii phng nhng cht mu ra nc thi lm nhim thm m v c th to ra cc sn phm ph nguy him thng qua qu trnh oxy ha trong nc thi.
19

2. NG DNG Oxy ha cc cht mu Phng php c in: Hp ph trn than hot tnh; Siu lc; Thm thu ngc; Keo t bi tc nhn ha hc; Trao i ion; ..

20

2. NG DNG Oxy ha thuc nhum H. Lachheb v cc cng s, nm 2002 kho st xc tc quang ha TiO2 dng dung dch huyn ph khi chiu x UV phn hy 3 loi thuc nhum: Congo Red (CR), Crocein Orange (OG), v Methyl Red (MR)

H. Lachhed et al., Appl. Catal. B: Environ. 39, 75 (2002)

21

2. NG DNG Oxy ha thuc nhum

H. Lachhed et al., Appl. Catal. B: Environ. 39, 75 (2002)

22

2. NG DNG trn Oxy ha

thuc nhum Acid Orange 7 (AO 7) khi s dng xc tc quang ha TiO2

W.Z. Tang, H. An, Chemosphere 31 (1995) 4157. V. Meshko, L. Markovska, M. Mincheva, A.E. Rodrigues, Wat. Res. 35 (2001) 3357. W.S. Kuo, P.H. Ho, Chemosphere 45 (2001) 77. C. Galindo, P. Jacques, A. Kalt, Chemosphere 45 (2001) 997.

23

2. NG DNG
Oxy ha thuc nhum aminoazobenzen (acid orange 52)

C. Galindo et al., 2000

C. Baiocchi, M.C. Brussino et al., 2002

24

2. NG DNG Oxy ha phenol Trong cng nghip v trong cuc sng hng ngy, hp cht phenol c s dng rng ri v tr thnh ngun nhim chnh trong nc. Bi v tnh n nh kh phn hy nn chng tn ti trong mi trng kh di. c tnh cao v c kh nng gy ung th ca nhng cht ny l nguyn nhn gy nh hng ca h sinh thi mi trng nc i vi sc khe con ngi
25

2. NG DNG Oxy ha phenol K thut x l nc c in loi phenol: Hp ph bng cacbon hot tnh; Oxy ha ha hc; Phn hy sinh hc.

26

2. NG DNG Oxy ha phenol Rahmani AR. PhD v cc cng s, nm 2008 kho st kh nng phn hy phenol bng xc tc quang ha TiO2 c s hin din UV.

27

2. NG DNG Oxy ha phenol

Rahmani AR. PhD et al., 2008

28

Rahmani AR. PhD et al., 2008

29

2. NG DNG Oxy ha phenol Kt qu ch ra rng pH = 11 kt hp vi UV th t kt qu tt nht. Sau 9 gi phn ng, lng phenol phn hy t hn 80%. iu ny c th gii thch, khi phenol trong mi trng kim (pH=11) s chuyn thnh dng ion phenoxide d phn hy hn phenol.
Rahmani AR. PhD et al., 2008
30

2. NG DNG Oxy ha cht kh

31

2. NG DNG Oxy ha cc cht kh Nitric oxide (NO v NO2) Sulfur dioxide (SO2) Cacbon monoxid (CO) Cc hp cht d bay hi (VOCs) nh hng nghim trng n sc khe nh gy bun ng, au u, au hng v tinh thn mt mi

32

2. NG DNG Oxy ha kh NO

Hnh 3. S h thng lm sch khng kh

C.H. Ao, S.C. Lee, 2003
33

2. NG DNG Oxy ha kh NO TiO2 (Degussa) dng thng mi. S dng mng lc c bit hiu qu cao (HEPA) v cacbon hot tnh (AC). Qut ly tm s dng hng khng kh i vo cht xc tc Ti b mt mng TiO2 c chiu UVA, UVC. Nng NO c o bng h thng phn tch NO Chemiluminescence (Thermo Environmental Instrument Inc. Model 42c)
C.H. Ao, S.C. Lee, 2003
34

2. NG DNG Oxy ha kh NO

Hnh S dng n UVA v UVC loi NO trn TiO2

C.H. Ao, S.C. Lee, 2003
35

2. NG DNG Oxy ha kh NO

Hnh 13. S dng TiO2 v TiO2/AC loi NO

C.H. Ao, S.C. Lee, 2003
36

2. NG DNG Oxy ha kh NO

Hnh 14. Sn phm trung gian t qu trnh phn hy NO cc iu kin khc nhau
C.H. Ao, S.C. Lee, 2003
37

2. NG DNG Oxy ha kh NO C ch phn hy NO bng TiO2 NO + HO* HNO2 HNO2 + HO* NO2 + H2O NO2 + HO* NO3- + H+

C.H. Ao, S.C. Lee, 2003

38

2. NG DNG Oxy ha kh CO Sangman Hwang v cc cng s, nm 2003 nghin cu kh nng oxy ha CO trn quang xc tc TiO2. Tc gi s dng 3 loi TiO2 thng mi: Degussa P25 (TiO2-D), ISK STS-01 (TiO2-I) v Hombikat UV-100 (TiO2-H) Mng TiO2 c ph trn a thy tinh din tch 2,25 cm2 s dng k thuc nhng ph.
Sangman Hwang et al., 2003
39

2. NG DNG Oxy ha kh CO

Hnh 15. Kh nng oxy ha CO trn cc h phn ng khc nhau theo thi gian
Sangman Hwang et al., 2003
40

2. NG DNG Oxy ha kh CO
C ch qu trnh oxy ha CO c m t

Sangman Hwang et al., 2003

41

2. NG DNG Oxy ha kh HCHO Formaldehyde (HCHO) t cc ta nh, t vt liu v cc sn phm tiu dng l mt trong ngun to VOCs bn mi trng ngoi. HCHO l nguyn nhn gy kch ng da, mt, ng h hp.

42

2. NG DNG Oxy ha kh HCHO Song Sun v cc cng s, vo nm 2010 nghin cu kh nng oxy ha ca xc tc quang ha TiO2. Tc gi s dng TiO2 thng mi (Degussa P25)

Song Sun et al., 2010

43

2. NG DNG Oxy ha kh HCHO

Hnh 16. chuyn ha formaldehyde thnh sn phm cui cng l CO2; a) khan, b) m
Song Sun et al., 2010
44

2. NG DNG Oxy ha kh HCHO

Hnh 17. C ch oxy ha formaldehyde trn TiO2 tinh khit; a) s dng gc t do O2-*, b) s dng gc t do HO* lm tc nhn oxy ha
Song Sun et al., 2010
45

2. NG DNG Oxy ha kh HCHO Tc phn hy HCHO trn TiO2 trong mi trng m c phn cao hn l do c s hin din ca nc, to ra gc t do *OH c th oxy ha cao, xc tin cho s hnh thnh formate trung gian, v sn phm cui cng l CO2 v H2O.

Song Sun et al., 2010

46

3. KT LUN

47

Ti liu tham kho

1. Nguyn c Ngha. Ha hc nano cng ngh nn v vt liu ngun. Nh xut bn Khoa hc t nhin v cng ngh, 283 305 (2007) 2. Trn Mnh Tr, Trn Mnh Trung. Cc qu trnh oxy ha nng cao trong x l nc v nc thi C s khoa hc v ng dng. Nh xut bn Khoa hc v k thut. (2006) 3. Hubert Gnaser, Bernd Huber, Christiane Ziegler, Nanocrystalline TiO2 for Photocatalysis, 505 535 (2004). 4. H. Lachheb et al., Application catalyst B: Environment. 39, 75 (2002) 5. Ioannis K. Konstantinou, Trianfafyllos A. Albanis, TiO2 assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic invesgations: A review. 2003. 6. Rahmani AR. PhD, Samadi MT. PhD, Enayati Moafagh A. Investigation of photocatalytic degradation of phenol by UV/TiO2 process in aquatic solutions. 2008. 7. C. H. Ao, S. C. Lee. Indoor air purification by photocatalyst TiO2 immobilized on an activated carbon filter installed in an air cleaner. 2003. 8. Q. L. Yu, H. J. H. Brouwers. Indoor air purification using heterogeneous photocatalytic oxidation. Part I: Experimental stuydy. 2009. 9. Sangman Hwang, Myung Churl Lee, Wonyong Choi. Highly enhanced photocatalytic oxidation of CO on titania deposited with Pt nanoparticles: kinetics and mechnism. 2003. 10. Song Sun, Jianjun Ding, Jun Bao, Chen Gao, Zeming Qi, Chengxiang Li. Photocatalytic Oxidation of Gaseous Formaldehyde on TiO2: An in situ Drifts study. 2010
48

Cm n c v cc bn theo di.

49