title: A new alkali-activated steel slag-based cementitious material for photocatalytic degradation of organic pollutant from waste water.
abstract: A new type of Ni,Ca-cementitious material was firstly synthesized via a two-step reaction of alkali-activated steel slag polymerization and ion exchange. The XRF results showed that almost all the Na(+) ions in the matrix of Na,Ca-cementitious material were replaced by Ni(2+) ions at room temperature. The new hydrated products of metahalloysite (Si(2)Al(2)O(5)(OH)(4)) and calcium silicate hydrate (CSH) were formed in the Na,Ca-cementitious material. The diffuse reflectance UV-vis near infrared ray spectrum was blue-shifted due to the strong interaction between Ni(2+) and negative charge of [AlO(4)](5-) tetrahedron in the framework of cementitious material. The Ni,Ca-cementitious material was used as a catalyst for the photocatalytic degradation of methylene blue dye and showed a degradation rate of 94.39% under UV irradiation. The high photocatalytic degradation activity was suggested to be the synergistic effect of the cementitious matrix, Ni(2+) ions and the iron oxides of wustite (FeO) and calcium iron oxide (Ca(2)Fe(2)O(5)) from the steel slag. A probable mechanism of photocatalytic oxidative degradation was proposed.
authors.affiliation: College of Material Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China. yaojzhang@yahoo.com.cn
authors.forename: Yao Jun
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Li Cai
authors.initials: LC
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.forename: Ya Chao
authors.initials: YC
authors.lastname: Wang
authors.forename: De Long
authors.initials: DL
authors.lastname: Xu
mesh_terms: D002384:Catalysis; D009930:Organic Chemicals / Q000737:chemistry*; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D019265:Spectroscopy, Near-Infrared; D013232:Steel; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D013232:Steel