Facile fabrication of a 2D/2D CoFe-LDH/g-C3N4 nanocomposite with enhanced photocatalytic tetracycline degradation.

Abstract

The widespread use of tetracycline (TC) in medicine and agriculture has caused severe pollution problems in the environment. In this work, a nanocomposite comprising of CoFe-layered double hydroxides grown on graphitic carbon nitride nanosheets (CoFe-LDH/g-C3N4) with a notable two-dimensional/two-dimensional (2D/2D) heterostructure was synthesized through a facile co-precipitation method. The CoFe-LDH/g-C3N4 nanocomposite displayed significantly improved visible-light-driven photocatalytic activity towards TC degradation, compared to pristine g-C3N4 and CoFe-LDH alone. The enhanced activation efficiency was a result of intimate interfacial contact, enlarged the surface area, broadened visible-light absorbance, and enhanced photogenerated electron transfer. The scavenging experiments showed that holes (h+) and superoxide radical anions (‧O2-) played a crucial role in TC degradation. Factors including the type of TCs, initial concentration of TC, presence of ions, and the type of water matrix were investigated to evaluate the practical feasibility of the nanocomposites for TC removal from antibiotics-contaminated water. The repeated tests showed that the nanocomposites possessed good stability and recyclability. This study demonstrated the feasibility of achieving photocatalytic activity enhancement of g-C3N4 through the formation of a 2D-2D heterostructure between LDHs and g-C3N4.