Super‐Stable, Highly Efficient, and Recyclable Fibrous Metal–Organic Framework Membranes for Precious Metal Recovery from Strong Acidic Solutions

Abstract

Precious metals such as palladium (Pd) and platinum (Pt) are marvelous materials in the fields of electronic and catalysis, but they are tapering day by day. Zr(IV)‐based metal–organic frameworks (MOFs) are competent for their recovery, notably in harsh environments, while the general powder form limits their practical application. Porous MOF‐based membranes with ultraefficient metal ion permeation, strong stability, and high selectivity are, therefore, strikingly preferred. Herein, a set of polymeric fibrous membranes incorporated with the UiO‐66 series are fabricated; their adsorption/desorption capabilities toward Pd(II) and Pt(IV) are evaluated from strongly acidic solutions; and the MOF–polymer compatibilities are investigated. Polyurethane (PU)/UiO‐66‐NH2 showed strong acid resistance and high chemical stability, which are attributable to strong π–π interactions between PU and MOF nanoparticles with a high configuration of energy. The as‐fabricated MOF membranes show extremely good adsorption/desorption performances without ruptures/coalitions of nanofibers or leak of MOF nanoparticles, and successfully display the efficacy in a gravity‐driven or even continuous‐flow system with good recycle performance and selectivity. The as‐fabricated MOF membranes set an example of potential MOF–polymer compatibility for practical applications.

Zirconium Metal–Organic Framework Materials for Efficient Ion Adsorption and Sieving

“…On the basis of the excellent precious metal ion adsorption property of Zr-MOFs, a set of polymeric fibrous membranes (FMs) incorporated with the UiO-66 series, including polyurethane (PU)/UiO-66, PU/UiO-66-NH 2 , polyacrylonitrile (PAN)/UiO-66, and PAN/UiO-66-NH 2 membranes were fabricated for adsorption of Pd II and Pt IV anions from strongly acidic solutions . Compared to the other three FMs, the PAN/UiO-66-NH 2 membrane showed the best adsorption capacities for Pd II (165 mg g –1 ) and Pt IV (172 mg g –1 ) with very good selectivity and adsorption/desorption performance.…”

Three-Dimensional MOF-Assisted Self-Polarized Ferroelectret: An Effective Autopowered Remote Healthcare Monitoring Approach

“…The attractive features of MOFs arise from their highly regulated and well-defined framework structures possessing nanochannels with a tunable size, shape, dimensionality, and surface environment. Due to their versatile properties, MOFs have been widely studied in several applications including gas storage, separation and sensing, catalysis, filtering device, electrical energy storage, optoelectronic components, nonvolatile memory element, and drug delivery. − Unfortunately, the powder form of MOF restricts its more diverse application. Particularly, MOF–polymer composites in the form of film, ink, and nanofibers are extensively studied to expand their versatility in different sensing platforms such as chemical protection and decontamination of chemical warfare agents, H 2 S sensing, metal recovery from acidic solution, chemosensor and thermosensor for aromatic pollutants, piezoresistive health monitoring, and motion sensing. − However, to date, the direct use of MOFs in autopowered pressure sensors, such as electronic skin, has been rarely studied.…”

ON/OFF Switchable Nanocomposite Membranes for Separations

“…Sensible researchers have come up with realistic alternatives instead of rejecting unrealistic industrial requirements. Their plan is to develop relatively inexpensive new materials [ 7 , 8 , 9 , 10 ], but to use a mixture of preexisting materials and design products such that they can perform only under certain conditions where external stimuli are transmitted so that frequent recycling processes are unnecessary. As such, two materials with conflicting characteristics—one organic with a stimuli-responsive switching property and the other inorganic—have been combined to create a “smart” response nanocomposite system [ 11 , 12 , 13 ].…”