Metal-organic framework membranes for wastewater treatment and water regeneration

Metal-organic framework (MOF), which is composed of metal ions and bridged organic ligands, are one of the most high-profile materials currently, because their regular and tunable pore structures confer unique properties. In particular, MOF materials have attracted widespread attention in the field of membrane separation, wherein water-stable MOF membranes stand out especially in the field of wastewater treatment and water regeneration. This review critically summarizes the various design and synthesis strategies of bare MOF membranes and MOF composite membranes. The formation and function of the structural defects in MOF play important roles in the performance of MOF-based membrane. Different characterization techniques are discussed systematically, and the applications of MOF membranes in membrane filtration, membrane distillation, and membrane pervaporation are described. In order to uncover the full potential of MOF-based membranes in wastewater treatment and water regeneration, current challenges are detailed and future research directions proposed.