One-dimensional nanomaterial-assembled macroscopic membranes for water treatment

With the worldwide exponential development of population and industrialization, water pollution has become a serious issue for flora, fauna and human beings. The increasing concerns on environment sustainability require one to develop advanced materials and technologies for high-performance water treatment. Nanomaterials, exhibiting advantages of high specific surface areas and controlled architectures thereof have been vastly developed for improving the treatment speed, efficiency and selectivity. Membranes are favored materials for water decontamination due to their solute selectivity, handling robustness, and easy operational process without extra energy input. In this scenario, the combination of nanomaterials and membrane technology during water cleaning is required for both scientific research and real-world applications. One-dimensional (1D) nanomaterials-based membranes (e.g., self-assembled nanowires, nanobelts/ribbons, nanotubes, nanofibers) possessing interconnected open pore structures and large surface areas, were widely used to remove oily contaminants, toxic metal ions, emulsions, nanoparticles, small organic molecules such as antibiotics and dyes from water. This review focuses on the water treatment by using these nanomaterial-based membranes, which will be categorized based on their functionalities, i.e., adsorption, separation, filtration and photocatalytic degradation. In each section, representative studies and recent advances will be described. Further, future perspectives and challenges are summarized and put forward for developing multifunctional nanomaterial-based membranes for environmental remediation.