Primary Photocalorimetry Investigation of the In-situ Photocatalytic Process of Methyl Orange Degradation†

doi:10.7503/cjcu20140176

Abstract

Abstract:

Ag@AgCl photocatalyst was prepared by reduction of AgCl precursor at room temperature, and characterised by X-ray powder diffraction(XRD) and field-emission scanning electron microscope(FE-SEM). A novel photoreaction-microcalorimetry was designed and employed to obtain the on-line thermodynamic and kinetic informations of photocatalysis of methyl orange over Ag@AgCl. The results showed that the degradation process went through an initial endothermic reaction and followed by an exothermic stage which finally kept a constant exothermic rate for at least 4 h. The heat effects of ab, ac, and ad stages were -0.2609, 2.5845 and 40.7289 J, respectively. Meanwhile, the steady rate of exothermic platform, the stage of cd, is 2.581 mJ/s. The microscopic mechanism of photodegradation was discussed in detail.

Key words: Photocatalysis under visible-light, Ag@AgCl, Photocalorimetry, Methyl orange, Photodegradation mechanism(Ed.: S, Z, M)

CLC Number:

O645

TrendMD:

LI Xingxing, HUANG Zaiyin, FAN Gaochao, WU Yenan, TAN Xuecai. Primary Photocalorimetry Investigation of the In-situ Photocatalytic Process of Methyl Orange Degradation^†[J]. Chem. J. Chinese Universities, 2014, 35(7): 1480.

Figures/Tables 3

Fig.1 Novel photoreaction-microcalorimetric system

Fig.2 XRD pattern(A) and SEM image(B) of Ag@AgCl a. XRD criterion pattern of AgCl; b. XRD pattern of as-prepared Ag@AgCl. Inset in (A): diffraction peak of Ag NPs.

Fig.3 Heat flow curves of photocatalysis of MO over Ag@AgCl under 25 ℃ during 0—15000 s(A) and 0—3000 s(B), UV-Vis spectrum during MO degradation with Ag@AgCl as photocatalyst(C) and MO degradation curves by using AgCl, Ag@AgCl as photocatalysts under 55 W LED irradiation(D) Insets in (B): (1) The initial solution; (2) the solution after reaction for 15 min.

References 20

[1]	Fujishima A., Honda K., Nature, 1972, 238, 37—38
[2]	Kudo A., Miseki Y., Chem. Soc. Rev., 2009, 38, 253—278
[3]	Chen C. C., Ma W. H., Zhao J. C., Chem. Soc. Rev., 2010, 39, 4206—4219
[4]	Wang J. G., Ji P. L., Kong X. Z., Chem. J. Chinese Universities, 2013, 34(11), 2635—2643
	(王金刚, 姬平利, 孔祥正. 高等学校化学学报, 2013, 34(11), 2635—2643)
[5]	Wang P., Huang B. B., Qin X., Qin X. Y., Zhang X. Y., Dai Y., Wei J. Y., Angew. Chem. Int. Ed., 2008, 47(41), 7931—7933
[6]	Chun H., Peng T. W., Hu X. X., J. Am. Chem. Soc., 2010, 132, 857—862
[7]	An C. H., Peng S., Sun Y. G., Adv. Mater., 2010, 22(23), 2570—2574
[8]	Cui Y. M., Photographic Sci. Photochem., 2004, 22(6), 434—443
	(崔玉民. 感光科学与光化学, 2004, 22(6), 434—443)
[9]	Liu B.S., Zhao X. J., The Heterogeneous Photocatalysis by Semiconductor: Thermodynamics Mechanism Study and Experimental Demonstration, Science Press, Beijing, 2013
	(刘保顺, 赵修建. 半导体异相光催化: 热动力学机制研究和实验论证, 北京: 科学出版社, 2013)
[10]	Magee J. L., DeWitt T. W., Smith E. C., Daniels F., J. Am. Chem. Soc., 1939, 61, 3529—3533
[11]	Seybold P. G., Gouterman M., Callis J., Photochem. Photobiol., 1969, 9(3), 229—242
[12]	Olmsted J. III, Rev. Sci. Instrum., 1979, 50(10), 1256—1259
[13]	Olmsted J. III, J. Am. Chem. Soc., 1980, 102(1), 66—71
[14]	Adamson A. W., Vogler A., Kunkely H., Wachter R., J. Am. Chem. Soc., 1978, 100, 1298—1300
[15]	Schaarschmidt B., Lamprecht I., Experientia, 1973, 29, 505—506
[16]	Teixeira C., Wadsö I., J. Chem. Thermodyn., 1990, 22, 703—713
[17]	Dhuna M., Beezer A.E., Connor J. A., Clapham D., Courtice C., Frost J., Gaisford S.,J. Pharm. Biomed. Anal., 2008, (48), 1316—1320
[18]	Dhuna M., Beezer A. E., Morris A. C., Gaisford S., Michael A. A., Hadgraft J., Connor J. A., Clapham D., Frost J., Rev. Sci. Instrum., 2007, 78(2), 0251051-1—0251051-5
[19]	Mukhanov V. S., Kemp R. B., J. Therm. Anal. Cal., 2009, 95, 731—736
[20]	Liu S.X., Liu H., Foundation and Application of Photocatalysis and Photoelectrocatalysis, Chemical Industry Press, Beijing, 2006
	(刘守新, 刘鸿. 光催化及光电催化基础与应用, 北京: 化学工业出版社, 2006)