Hierarchical MOF-74/Cu2O/Cu composite derived from metal-organic frameworks toward degradation of 4-nitrophenol

Abstract

Metal-organic frameworks (MOFs) are recognized as advanced functional materials and ideal sacrificial templates due to their high specific area, abundant active sites, well-organized framework structure, and diverse morphologies. However, single component MOFs have been unable to meet the increasing application requirements. Herein, MOF-74 was used as a sacrificial template to synthesize a composite material MOF-74/Cu2O/Cu by calcinating hierarchical MOF-74 at 250 "℃" . A series of characterization techniques were employed to analyse the morphology, chemical components, and valence state of Cu in the MOF-74/Cu2O/Cu. The results revealed that the MOF-74/Cu2O/Cu inherits the hierarchical structure of parent MOF-74, which is constructed by nanosheets. Furthermore, particial Cu2+ nodes were transformed into Cu2O and Cu during the pyrolysis process of MOF-74, resulting in the formation of multicomponent composite material MOF-74/Cu2O/Cu. Considering its multicomponent and hierarchical structure, the catalytic performance of MOF-based composite material was evaluated for degrading 4-NP in the presence of NaBH4. Additionally, the presence of Cu2O and Cu was found to effectively shorten induction period for reducing 4-NP and enhance the catalytic rate. Moreover, MOF-74/Cu2O/Cu presented improved catalytic in the degradation of the dyes MO and MB. This study proposes a facile approach for synthesizing multiple phase composites based on the incompletely pyrolysis of MOFs, aiming to advance the development of functional materials.