Ball-milled bismuth oxychloride/biochar nanocomposites with rich oxygen vacancies for reactive red-120 adsorption in aqueous solution

Fabricating surface oxygen vacancies is considered to be an efficient method to improve the adsorption performance of sorbents.In this work,a bismuth oxychloride/biochar(BiOCl/BC)nanocomposite with abundant oxygen vacancies was successfully prepared by a facile ball milling method.BiOCl/BC nanocomposite was found to have excellent adsorption performance for removing reactive red-120(RR120)from aqueous solution.The effects of key adsorption parameters,such as RR120 dye concentration,solution pH(2-10),and contact time were studied by batch adsorption test.The adsorption data were well described by the Langmuir and Freundlich isotherms and pseudo-second-order kinetic models.The 50%-BiOCl/BC(50 wt%of BiOCl in composite)exhibited the best adsorptive performance(60%),much better than the pristine BM-BC(20%).The high adsorption capacity of 50%-BiOCl/BC(Langmuir maximum capacity of 116.382 mg g^(−1))can be attributed to the electrostatic effect,π-πinteractions,and hydrogen bond.This work provided a facile method to prepare semiconductor assisted biochar-based adsorbents,which would also contribute to the advance of environmental remediation.