The Preparation of Porous Activated Slag Granules/TiO₂ Photocatalyst and Its De-NO _x Performance

Abstract

The porous structure and honeycombed structure of granulated blast furnace slag formed by alkali activation (AGBFS) can be used as a promising photocatalysts substrate for the photocatalytic removal of atmospheric or water pollutants. In this study, photocatalytic activated slag granules were synthesized by loading TiO₂ on AGBFS with immersion method. The physicochemical properties and NO _x removal performance of activated slag granules/TiO₂ photocatalysts were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and photocatalytic performance test. The effects of slag particle sizes and nano-TiO₂ loading concentrations on photocatalytic efficiencies of NO _x removal were also investigated. It was found that the De-NO _x performance of activated slag granules/TiO₂ photocatalyst increased with the increasing of slag particle size in low TiO₂ loading concentration situation, while increasing the TiO₂ loading concentration would result in the opposite De-NO _x performance as slag size increased. Nevertheless, for the same size activated slag, the photocatalytic efficiency of activated slag granules/TiO₂ photocatalyst gradually improved with the increase of loading concentration of TiO₂.

Keywords

granulated blast furnace slag / porous structure / alkali-activation / photocatalysis / NO _x

References

[1] Zhang L. Study on Preparation and Photocatalytic Properties of Alkali-activated Granulated Blast Furnace Slag-based Conductive Cementitious Composite[D], 2018 Xi’an: Xi’an University of Architecture and Technology.

[2] Yang K H, Sim J I, Nam S H. Enhancement of Reactivity of Calcium Hydroxide-activated Slag Mortars by the Addition of Barium Hydroxide[J]. Construction and Building Materials, 2010, 24(3): 241-251.

[3] Wang P Z, Trettin R, Rudert V, Umlauf R. Recrystallisation of Granulated Blast-furnace Slags and the Significance for the Hydraulic Reactivity[J]. Advances in Cement Research, 2003, 15(1): 29-33.

[4] Salahuddin M B M, Norkhairunnisa M, Mustapha F. A Review on Thermophysical Evaluation of Alkali-activated Geopolymers[J]. Ceramics International, 2015, 41: 4273-4281.

[5] Rashad A M. Alkali-activated Metakaolin: A Short Guide for Civil Engineer-An Overview[J]. Construction and Building Materials, 2013, 41: 751-765.

[6] Zhang Y J, Yang M Y, Kang L, et al. Research Progresses of New Type Alkali-activated Cementitious Material Catalyst[J]. Journal of Inorganic Materials, 2016, 31(3): 225-233.

[7] Wang P Z, Hao L S. The Separation of Primary Mineral Phase in Granulated Blast-furnace Slag[J]. Journal of Shanxi Datong University, 2008 (5): 44–47

[8] Zhu K Z, Qin Y M, Hou S, et al. Experimental Study of Cement Grinding Aids Using in Slag Grinding[J]. Cement Engineering, 2017 (3): 4–6, 22

[9] Liu H, Zhou Z H, Wang X H, et al. Preparation and Photocatalytic Activities of Photocatalysts From High-iron Slag[J]. Industrial Safety and Environmental Protection, 2012, 38(1): 84-87.

[10] Natali A, Manzi S, Bignozzi M C. Novel Fiber-reinforced Composite Materials Based on Sustainable Geopolymer Matrix[J]. Procedia Engineering, 2011, 21(3): 1124-1131.

[11] Rashad A M. A Comprehensive Overview about the Influence of Different Additives on the Properties of Alkali-activated Slag-A Guide for Civil Engineer[J]. Construction and Building Materials, 2013, 47(10): 29-55.

[12] X X, Wang Z G, Liu SH. Mechanism of Application of Ground Mineral Admixtures in Cement Based Materials[J]. Coal Ash, 2015, 27(6): 16-19.

[13] Wei R L, Li H. Status of Recycling Technology of Blast Furnace Slag[J]. Journal of Xi’an University of Architecture & Technology (Natural Science Edition), 2010, 42(03): 446-450.

[14] Wei G H, Zhang C L, Zhu H Y. The Durability of Applying Ground Granulated Slag in Concrete[J]. Concrete, 2004, (11): 38–41, 53

[15] Oner M. A Study of Intergrinding and Separate Grinding of Blast Furnace Slag Cement[J]. Cement and Concrete Research, 2000, (30): 473–480

[16] Erdogdu K, Tokyay M, Turker P. Comparison of Intergrinding and Separate Grinding for the Production of Natural Pozzolal and GBFS-incorporated Blended Cements[J]. Cement and Concrete Research, 1999, (29): 743–746

[17] Wang J D, Lu H G, Tian Q Y. Research on the Mechanism of Action of Grinding Aids on High Blast Furnace Slag[J]. Journal of Tonggi University (Natural Science), 1996, 24(6): 660-664.

[18] Zhang Y J, Liu L C, Ni L L, et al. A Facile and Low-cost Synthesis of Granulated Blast Furnace Slag-based Cementitious Material Coupled with Fe₂O₃ Catalyst for Treatment of Dye Wastewater[J]. Applied Catalysis B: Environmental, 2013, 138–139(28): 9-16.

[19] Zhang Y J, Yang M Y, Zhang L, et al. A New Graphene/Geopolymer Nanocomposite for Degradation of Dye Wastewater[J]. Integrated Ferroelectrics, 2016, 171(1): 38-45.

[20] Gasca-Tirado J R, Manzano-Ramírez A, Vazquez-Landaverde P A, et al. Ion-exchanged Geopolymer for Photocatalytic Degradation of A Volatile Organic Compound[J]. Materials Letters, 2014, 134(11): 222-224.

[21] Falah M, Mackenzie K J D, Knibbe R, et al. New Composites of Nanoparticle Cu (I) Oxide and Titania in A Novel Inorganic Polymer (Geopolymer) Matrix for Destruction of Dyes and Hazardous Organic Pollutants[J]. Journal of Hazardous Materials, 2016, 318: 772-782.

[22] Yang L, Hakki A, Wang F Z, et al. Photocatalyst Efficiencies in Concrete Technology: The Effect of Photocatalyst Placement[J]. Applied Catalysis B Environmental, 2018, 222: 200-208.

[23] Yang L, Hakki A, Zheng L, et al. Photocatalytic Concrete for NOx Abatement: Supported TiO₂ Efficiencies and Impacts[J]. Cement and Concrete Research, 2019, 116: 57-64.