Fabrication and Photocatalytic Performance of GaN/ZnO Composites

doi:10.15541/jim20130617

Abstract

Abstract:

GaN powder was firstly synthesized by the Sol-Gel method using polyvinylpyrrolidone (PVP) and gallium nitrate [Ga(NO₃)₃] as surfactant and gallium source, respectively. Then, GaN/ZnO composites were prepared by solid phase method through mechanical mixing GaN powder and ZnO powder with different proportions. The composites were characterized by using X-Ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), high-resolution X-ray electron microscope (HRTEM) and photoluminescence (PL) spectra. The photocatalytic performance of GaN/ZnO composites as catalyst was tested by degradation of methylene blue in aqueous solution under white light irradiation. The results show that the photocatalytic property of GaN/ZnO composites is obviously improved comparing with that of pure GaN and ZnO powders. The photocatalytic activity is analyzed by pseudo-first-order kinetics equation, showing that the best photodegradation rate constant k is 0.11 min^-1 for the GaN/ZnO composites with GaN and ZnO mixing ratio of 1: 2.

Key words: GaN/ZnO composites, photocatalysis, methylene blue, reaction kinetics

CLC Number:

O643

PENG Dan, ZHENG Xue-Jun, XIE Shu-Fan, LUO Xiao-Ju, WANG Ding. Fabrication and Photocatalytic Performance of GaN/ZnO Composites[J]. Journal of Inorganic Materials, 2014, 29(9): 956-960.

Figures/Tables 6

Fig. 1 XRD patterns of GaN/ZnO composites

Fig. 2 SEM images of GaN/ZnO composites with different ratios and EDS images of GaN/ZnO composites with ratio of 1: 1 (a) GaN; (b) GaN: ZnO=4: 1; (c) GaN: ZnO=1: 1; (d) GaN: ZnO=1: 2; (e) GaN: ZnO=1: 4; (f) ZnO; (g) EDS of hollow cross fork; (h) EDS of solid cross fork

Fig. 3 TEM (a) and HRTEM (b) images of GaN/ZnO composites

Fig. 4 PL spectra of GaN/ZnO compositesInset is the PL spectra of GaN powder

Fig. 5 Absorption spectra of the methylene blue solution at different time intervals with GaN/ZnO composites (a) GaN; (b) GaN: ZnO=4: 1; (c) GaN: ZnO=1: 1; (d) GaN: ZnO=1: 2; (e) GaN: ZnO=1: 4; (f) ZnO

Fig. 6 Methylene blue solution degradation efficiency with irradiation time (a) and relationship between ln(C0/C) and irradiation time (b) with GaN/ZnO composites

References 22

[1]	FUJISHIMA A, HONDA K. Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238: 37-38.
[2]	KEMPA T J, CAHOON J F, KIM S K, et al. Coaxial multishell nanowires with high-quality electronic interfaces and tunable optical cavities for ultrathin photovoltaics. Proceedings of the National Academy of Sciences, 2012, 109(5): 1407-1412.
[3]	HOCHBAUM A I, CHEN R, DELGADO R D, et al. Enhanced thermoelectric performance of rough silicon nanowires. Nature, 2008, 451(10): 163-167.
[4]	HU Y F, ZHANG Y, XU C, et al. High-output nanogenerator by rational unipolar assembly of conical nanowires and its application for driving a small liquid crystal display. Nano Letters, 2010, 10(12): 5025-5031.
[5]	LI Z, WANG Z L. Air/liquid-pressure and heartbeat-driven flexible fiber nanogenerators as a micro/nano-power source or diagnostic sensor. Advanced Materials, 2011, 23(1): 84-89.
[6]	JUNG H S, HONG Y J, LI Y, et al. Photocatalysis using GaN nanowires. ACS Nano, 2008, 2(4): 637-642.
[7]	KIDA T, MINAMI Y, GUAN G, et al. Photocatalytic activity of gallium nitride for producing hydrogen from water under light irradiation. Journal of Materials Science, 2006, 41(11): 3527-3534.
[8]	CAO T P, LI Y J, WANG C H. Preparation and photocatalytic property of NiO/ZnO heterostructured nanofibers. Journal of Inorganic Materials, 2013, 28(3): 295-300.
[9]	ZHOU W Q, LU Y M, CHEN C Z, et al.Effect of Li-doped TiO2 compact layers for dye sensitized solar cells. Journal of Inorganic Materials, 2011, 26(8): 819-822.
[10]	CAO T P, LI Y J, SHAO C L, et al. Fabrication, structure, and enhanced photocatalytic properties of hierarchical CeO2 nanostruc-tures/TiO2 nanofibers heterostructures. Materials Research Bulletin, 2010, 45(10): 1406-1412.
[11]	YU C L, YANG K, YU J C, et al. Hydrothermal synthesis and photocatalytic performance of Bi2WO6/ZnO heterojunction photoca-ta-lysts. Journal of Inorganic Materials, 2011, 26(11): 1157-1163.
[12]	LIU S X,LIU H. Basic and Application of Photocatalytic and Photoelectrocatalytic. Beijing: Chemical Industry Press, 2006.
[13]	MAEDA K, TAKATA T, HARA M, et al. GaN: ZnO solid solution as a photocatalyst for visible-light-driven overall water splitting. Journal of the American Chemical Society, 2005, 127(23): 8286-8287.
[14]	ZHU Z F, WANG Y, LI J Q, et al. The synthesis of 3D Bi2WO6/TiO, heterojunction photocatalysts and enhanced photocatalytic activity. Journal of Functional Materials, 2013, 44(16): 2324-2328.
[15]	DENG Q, LI M, CAI Q, et al. Preparation of rare earth/titanium dioxide catalysts and photocatalytic elimination of gaseous pollutant. Journal of the Chinese Society of Rare Earths, 2011, 29(2): 170-177.
[16]	JING L Q, ZHENG Y G, XU Z L, et al. Electronic paramagnetic resonance characteristics of ZnO ultrafine particlesand their photocatalytic performance. Chemical Journal of Chinese Unive-rsities, 2001, 22(11): 1885-1888.
[17]	XIE S F, LIU Y Y, CHEN Z L, et al. Superior photocatalytic properties of phosphorous-doped ZnO nanocombs. RSC Advances, 2013, 3(48): 26080-26085.
[18]	QIAN P P, XUE J L, FAN G X, et al. Photocatalytic degradation properties of methylene blue over ZnAl layered double hydroxides. Chinese Journal of Inorganic Chemistry, 2012, 28(7): 1348-1352.
[19]	NAGESWARA R A, SIVASANKAR B, SADASIVAM V. Kinetic study on the photocatalytic degradation of salicylic acid using ZnO catalyst. Journal of Hazardous Materials, 2009, 166(2): 1357-1361.
[20]	MOHAMED R M, BAEISSA E S, MKHALID I A, et al. Optimization of preparation conditions of ZnO-SiO2 xerogel by Sol-Gel technique for photodegradation of methylene blue dye. Applied Nanoscience, 2013, 3(1): 57-63.
[21]	YAN J H, ZHANG L, ZHU Y R, et al. Preparation and photocatalytic hydrogen production of NiO(CoO)/N-SrTiO3 heteroj-un-ction complex catalyst under simulated sunlight irradiation. Journal of Inorganic Materials, 2009, 24(4): 666-670.
[22]	WANG X, XU Q, LI M, et al. Photocatalytic overall water splitting promoted by an α-β phase junction on Ga2O3. Angewandte Chemie International Edition, 2012, 51(52): 13089-13092.