Mesotubular‐Structured Hybrid Membrane Nanocontainer for Periodical Monitoring,Separation, and Recovery of Cobalt Ions from Water

Exposure to toxins can cause deleterious effects even at very low concentrations. We have developed an optical sensor, filter, and extractor (i.e., containerlike) in a nanoscale membrane (NSM) for the ultratrace sensing, separation, and recovery of Co²⁺ ions from water. The design of the NSM is successfully controlled by dense decoration of a hydrophobic oil‐hydrophilic receptor onto mesoscale tubular‐structured silica nanochannels made of a hybrid anodic alumina membrane. The particular structure of the nanocontainer is ideal to control the multiple functions of the membrane, such as the optical detection/recognition, rejection/permeation, and recovery of Co²⁺ species in a single step. A typical sensor, filter, and extractor assessment experiment was performed by using a benchtop contact time technique and a flow‐through cell detector to allow for precise control of the optical detection and exclusive rejection of target ions and the permeation of nontarget metal ions in water. This nanocontainer membrane has great potential to meet the increasing needs of purification and separation of Co²⁺ ions.