Preparation and characterization of Ni-doped calcium silicate hydrate based on steel slag: Adsorption capacity for rhodamine B from aqueous solution

Calcium silicate hydrate based on steel slag (scsh) and ni-doped scsh (nscsh) were synthesized under specific hydrothermal conditions at saturated vapor pressure and 185°c for 7 hours. the structure and morphology of scsh and nscsh were characterized by xrd,sem,and n2 adsorption/desorption. scsh mainly consisted of amorphous calcium silicate hydrate gel (c-s-h gel) together with some flake-like tobermorite and nscsh consisted of crystalline tobermorite and xonotlite. the addition of ni(no3)2 had great influence on microstructure of the composites,and scsh possesses a mesoporous structure with slit-shaped pores,but nscsh has narrow distributions of pore size. furthermore,nscsh has a higher adsorption capacity for rhodamine b (rhb) than scsh with removal percentages of rhb of about 52.4% and 88.2%,respectively. in addition,the effects of nscsh dosage and ph values on the adsorption of rhb were investigated. adsorption isotherm parameters are obtained from both langmuir and freundlich analysis and showed a better fit to a langmuir model. all results indicated that nscsh has a great potential to be a safe,easily-made,and cost-effective material for the control of rhb contamination. © 2015 lu zeng and ligang yang.