TY - JOUR
T1 - The influence of zeolites fly ash bead/TiO2 composite material surface morphologies on their adsorption and photocatalytic performance
AU - Yang, Lu
AU - Wang, Fazhou
AU - Hakki, Amer
AU - Macphee, Donald E.
AU - Liu, Peng
AU - Hu, Shuguang
N1 - Acknowledgment
The authors would like to acknowledge the financial support from the Engineering and Physical Sciences Research Council of UK − Natural Science Foundation of China (EPSRC-NSFC) International Joint Research Project (51461135005).
PY - 2017/1/15
Y1 - 2017/1/15
N2 - A low cost zeolite fly ash bead/TiO2 (ZFABT) composite materials with various surface structure features were prepared for describing those structures importance on TiO2 coating, adsorbability and photocatalytic performances. The results indicated that fly ash bead (FAB) surface was significantly altered by the precipitation/growth of secondary zeolite phases after alkali activation, which generates abundant open pores and stacked petal-liked spherical beads (∼2 μm, Sodalite zeolites). More importantly, this porosity increases as activation time was increased from 2 h to 12 h, through the precipitation of sodalite and then Na-P1 (lamellar crystals) and Na-X (octahedral crystals) zeolite structures. Compared to those of unsupported TiO2 or inactivated support/TiO2 samples, all of ZFABT samples exhibited a higher adsorption capacity and photocatalytic efficiency for RhB removal. However, adsorption is not only one factor to influence TiO2 surface reaction, the intraparticle diffusion rate of rhodamine B (RhB) molecules, and light penetration are also important parameters. Alkali activated 4 h ZFABT sample exhibited the highest photocatalytic activity, indicating its pore structure provided a better balance for those parameters to achieve a synergistic adsorption/photocatalytic process. The kinetics model suggested its high intraparticle diffusion rate allowed for more RhB molecules to easily reach the reaction surface, which is more important for high efficiency photocatalysis.
AB - A low cost zeolite fly ash bead/TiO2 (ZFABT) composite materials with various surface structure features were prepared for describing those structures importance on TiO2 coating, adsorbability and photocatalytic performances. The results indicated that fly ash bead (FAB) surface was significantly altered by the precipitation/growth of secondary zeolite phases after alkali activation, which generates abundant open pores and stacked petal-liked spherical beads (∼2 μm, Sodalite zeolites). More importantly, this porosity increases as activation time was increased from 2 h to 12 h, through the precipitation of sodalite and then Na-P1 (lamellar crystals) and Na-X (octahedral crystals) zeolite structures. Compared to those of unsupported TiO2 or inactivated support/TiO2 samples, all of ZFABT samples exhibited a higher adsorption capacity and photocatalytic efficiency for RhB removal. However, adsorption is not only one factor to influence TiO2 surface reaction, the intraparticle diffusion rate of rhodamine B (RhB) molecules, and light penetration are also important parameters. Alkali activated 4 h ZFABT sample exhibited the highest photocatalytic activity, indicating its pore structure provided a better balance for those parameters to achieve a synergistic adsorption/photocatalytic process. The kinetics model suggested its high intraparticle diffusion rate allowed for more RhB molecules to easily reach the reaction surface, which is more important for high efficiency photocatalysis.
KW - Alkali activation
KW - Enhanced adsorption
KW - Intraparticle diffusion
KW - Photocatalysis
KW - TiO
KW - Zeolite fly-ash bead
UR - http://www.scopus.com/inward/record.url?scp=84988736420&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2016.09.023
DO - 10.1016/j.apsusc.2016.09.023
M3 - Article
AN - SCOPUS:84988736420
VL - 392
SP - 687
EP - 696
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
ER -