Novel functionalization of ZIF-67 for an efficient broad-spectrum photocatalyst: formaldehyde degradation at room temperature

Abstract

Indoor formaldehyde (HCHO) (emitted from furniture and/or wood products) causes widespread concerns, and photocatalysis is one of the effective methods to degrade HCHO. In this work, we prepared a new MOF-based photo-catalyst by modifying ZIF-67 (modified ZIF-67, ZIF-67-F) via a low-temperature thermal treatment, which allows the conversion of –NC– groups in ZIF-67 to –NCO, effectively expending the limited light absorption of ZIF-67 from 200–310 nm and 500–620 nm to a broad absorption in the UV-visible region of 200 to 780nm. In addition, the dissociation of the functional groups (–CH₃) on ZIF-67 creates more cavities and improves the porous ZIF-67-F material. Benefiting from the excellent light excitation and adsorption performance, ZIF-67-F can successfully degrade 87.8% HCHO at room temperature, where, ˙O₂⁻ is the main active species in the degradation reactions. In addition, ZIF-67-F shows great stability and reusability.