Multipurpose adsorption applications of boron-doped and amino-functionalized magnetic mesoporous silica nanocomposite

Abstract

In this study, boron-doped magnetic mesoporous silica nanocomposite was prepared through the hydrothermal synthesis procedure followed by post modification with –NH2 groups. The higher surface area, more ordered mesoporous structure, and higher surface charge density obtained by boron doping and amino functionalization contributed to the use of nanocomposite for multipurpose application functions. When used as an adsorbent for light green (LG) anionic dye, boron-doped nanocomposite exhibited higher adsorption capacity (105.80 mg/g) compared to undoped nanocomposite (72.23 mg/g), while when used as a drug carrier for Doxorubicin (DOX), a sufficient drug loading capacity (48.0 mg/g) was obtained, which is also higher than that of undoped nanocomposite (30.3 mg/g). In terms of LG adsorption, the effects such as initial concentration, adsorbent dosage, time, pH, and temperature on the adsorption properties were investigated in detail. Adsorption kinetics, isotherms, thermodynamics, and reusability are discussed. The existence of small quantity of boron doping enhanced the surface charge density from 0.0393 to 0.2854 C/m2, which resulted in higher adsorption capacity for LG adsorption dominated by electrostatic attraction, and led to formation of silanol holes together with the –OH and –NH2 functional groups, which resulted in higher drug loading capacity for DOX adsorption dominated by hydrogen bonding. This promising result provides that boron-doped and –NH2 grafted magnetic mesoporous silica material can function as multipurpose adsorbent for various environmental applications.