CHEM ICAL JOU RNAL O F CH IN ESE UN IV ERS IT IES V (vṡ [1, 2 ]. OH OH :

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1 V ol. 23 N o CHEM ICAL JOU RNAL O F CH IN ESE UN IV ERS IT IES ,,,, (, ) ( ),., T io 2, V (vṡ SCE),, H 2O 2,,. ; ; T io 2 ; ; O A (2002) , [1, 2 ]. OH ( ), [3 ]. OH, V, (2. 87 V ),,, CO 2 H 2O, [4 ]. OH Fenton ( H 2O 2 Fe 2+ ) [5 ], [6 ] H 2O 2 O 3 [7 ] [8, 9 ].,, H 2O 2 (O 2+ 2H + + 2e H 2O 2), [10 ]., T io 2,, OH H 2O 2,, [ 10 ], (PT FE), T io 2. ( 40 nm ) T io 2 ( ), 2. 2 T io 2,.,, m in., ggcm () ml,, R u2t i2o SnO 22FgT i,.. H T 21712H (5). : : ( : ). : (1946 ),,,. E2m ail: nccai@w hu. edu. cn

2 1152 V ol. 23 A. R.. F ig. 1 Schema tic represen ta tion of the reaction appara tus 1. Composite electrode or carbon2ptfe (air) O 2 electrode(12 cm 8 cm ) ; 2. Ru2T i2o or SnO 22FgT i anode; 3. low p ressure m ercury lamp (8 W, 254 nm ) ; 4. m agnetic stick; 5. D. C. constant current regulatoṙ 1. 3 TiO 2 F ig. 2 Schema tic represen ta tion of the polar iza tion curvesmea suremen t appara tus W : W orking electrode; R: reference electrode(sce) ; C: counter electrode(p t). ik: dark current; ip: photocurrenṫ 2. T io W T io 2 128A. X 2Y 2. O 2, H2O 2 H 2O 2, O 2 2 (O 2+ 2H + + 2e H 2O 2), H 2O (COD ) ( ). COD (Ν), Ν% = ( [COD ]0 - [COD ] t) g[cod ]0, [COD ]0 [COD ] t. COD HH H2O 2 JEOL JEM 2100Xg. 3 SEM, T io 2,. 4, ( 4 a) H 2O 2, 15 ma gcm 2 85%.,, H 2O 2,. T io 2, H 2O 2, i 15 ma gcm 2 80%. T io 2 ( 3) H 2O 2, H 2O 2 F ig. 3 The SEM of the composite electode

3 N o. 6 : 1153,. T io 2 ( 5 b), V (vṡ SCE ),,,., [11 ].,,, [12, 13 ] V, T io V, ( 5 a), V F ig. 4 Rela tion sh ip of the curren t eff ic iency (Γ) of genera ting H2O2 a. Carbon2PTFE (air) O 2 electrode; b. composite electrode. 12 ma gcm 2, H 2O 2 ( 4) V (vṡ, SCE), H 2O 2.,, ( 6). H 2O 2 T io 2, OH, (RH ) ( )., T io 2 (e - ) (h + ),,,, H 2O OH,,, OH (6). T io 2gT io 2,.,,. F ig. 5 Ca thode polar iza tion curve of the composite electrode ( a ) and the var ia tion of the photocurren t w ith poten tia l of TiO2 photoca ta lyst(b) 2. 2 F ig. 6 Combina tion of photo-ca ta lysis and photochem ica l ox ida tion on the degrada tion of organ ic m olecule in the com posite electrode system RH: O rganic molecule; R: oxidation p roducts of organic molecule. 7 1 COD. 7 a ( 10 ma gcm 2 ) R u2t i2o, H 2O 2. 7 b, H 2O 2, a. 7 c b, (i= 0, H 2O 2 ),. T io 2.,

4 1154 V ol. 23 c, 7 d. 7d b, c,, ( 7 b) ( 7 c),. [ 12, 14 ], 2Fenton ( H 2O 2, Fe 2+ )., OH F ig. 7 Var ia tion of the remova l percen tage (Ν) of COD in H 2O 2, solution w ith the increa se of reaction tim e ( t ) H 2O 2 Fe 2+ Fenton under differen t reaction condition s [Fe 2+ + H 2O 2 Fe (OH ) 2+ + OH ] c (A niline) = 10-3 molgl, c(k2so 4) = 0125 molgl, ph = Fe (OH ) 2+ [ Fe (OH ) 2+ + hμ Fe a. Carbon2PTFE (air) O 2 electrode as the cathode, Ru2 OH ] [12, 14 ], OH., 2Fenton T io 2 2 Fenton ( 8), 2Fenton T i2o as the anode and non2radiation, i= 10 ma gcm 2 ; b. under radiation, other conditions are the sam e as a; c. under radiaton, composite electrode rep lacing the carbon2 PTFE (air) O 2 elecrode as the cathode, i= 0; d. under radiaton, composite electrode rep lacing the carbon2ptfe (air) O 2 elecrode as the cathode, i= 10 ma gcm 2. 2Fenton,, h, COD 90%., 5 h. (4 h), 13%. 2Fenton 2Fenton. 10 ma gcm 2. COD, T io 2. 9, < 20 ma gcm 2 [> 0 V (vṡ SCE) ],,,, ( 5). i> 20 ma gcm 2, H 2O 2 ( 4), T io 2,,.,, ma g cm 2, V (vṡ SCE). F ig. 8 Var ia tion of the remova l percen tage (Ν) of COD in solution w ith the increa se of reaction tim e ( t ) in differen t reaction system s Cathode: i= 10 ma gcm 2, solution: c(aniline) = molgl, c(fe 2+ ) = molgl, ph = 315. a. Photo2Fenton systym; b. photo2fenton system w ith composite electrode. F ig. 9 Inf lunce of curren t den sity of the composite electrode (a) and Carbon-PTFE[a ir O2 electrode (b) ] on the remova l percen tage (Ν) of COD in solution Reaction tim e: 2 h, c(aniline) = molgl, c(k2so 4) = 0125 molgl, ph = 5.

5 N o. 6 : T io 2, H 2O 2,. T io 2, H 2O 2, V (vṡ SCE).,, ( ). [ 1 ] Enrique B rillas, Rosa M aria Bastida, E lisabet L losa et al. J. E lectrochem. Soc. [J ], 1995, 142 (6) : [ 2 ] Enrique B rillas, Eva M uṙ. J. E lectrochem. Soc. [J ], 1996, 143 (3) : L 49 L 53 [ 3 ] O turan M. A.. J. App l. E lectrochem. [J ], 2000, 30: [ 4 ] Polcar A. M., Palm as S., Renoldi F. et al.. J. App l. E lectrochem. [J ], 1999, 29: [ 5 ] R ichard G.. Zepp. Environ. Sci. Technol. [J ], 1992, 26 (2) : [ 6 ] Stucki S., Kota R., Carcer B. et al.. J. App l. E lectrochem. [J ], 1991, 21: [ 7 ] Glaze W. H., Koang J. W., Chap in D. H.. O zone Sci. Eng. [J ], 1987, 9 (4) : [ 8 ] XU Yi2M ing ( ). Chem. J. Chinese U niversities() [J ], 2000, 21 (10) : [ 9 ] ZHAN G Q ing2hong ( ), GAO L ian ( ), GUO J ing2kun ( ). Chem. J. Chinese U niversities() [J ], 2000, 21 (10) : [ 10 ] WAN G Yu2L ing ( ), CA IN ai2cai( ), ZHAN G Hui2Song ( ) et al.. Chem. J. Chinese U niversities( ) [J ], in p ress [ 11 ] ZHA Q uan2xing ( ). The Dynam ics of E lectrode P rocess( ) [M ], Beijing: Science P ress, 1987: [ 12 ] V inodgopal K., Hotchandani S., P rashant V. K.. J. Phy. Chem. [J ], 1993, 97: [ 13 ] Dong Hyun Kim, A nderson M. A.. Environ. Sci. Technol. [J ], 1994, 28: [ 14 ] W ang Y., Hong C2S.. W aṫ Reṡ [J ], 1999, 33 (9) : Prepara tion of the Novel D ouble-functiona l Com posite Electrode and Its Role on the D egradation of Organ ic Pollutan ts in Water WAN G Yu2L ing, CA IN ai2cai 3, WAN G Ya2P ing, L I J in, ZHON G J ia2sheng (Colleg e of Chem istry and M olecular S cience, W uhan U niversity, W uhan , China) Abstract T he m ethods for p reparing the novel composite electrode, the double function of the novel composite electrode and the role of it on increasing the degradation rate of the organic pollutants ( such as an iline) in w ater are in troduced. T he reaction m echan ism is also discussed. T he results indicate that w hen the work ing potential w as controlled at V or so, the composite electrode m ade up of the carbon2 PT FE (air) O 2 electrode and the T io 2 photo2catalyst not only possesses photocurrent effect but also has a h igh efficiency of generating H 2O 2. T hen the organic molecule in solution can obtain two k inds of roles on degradation com ing from the com bination of the pho to2catalysis and the pho tochem ical ox idation. T he rate of degradation of the organic molecule is obviously enhanced. Keywords Composite electrode; Carbon2PT FE (air) O 2 electrode; T io 2 photo2catalyst; D egradation; A niline (Ed. : V, X)