A recent development on core-shell-based material and their application in membranes for water and wastewater treatment

The increasing demand for clean water urges many attempts to treat wastewater. The excessive presence of organic waste and many pollutants threatens human health, potentially resulting in various forms of discomfort and negative consequences. Many materials used have been modified vividly to solve the problem mentioned. Core-shell-based material as a catalyst and adsorbent is one of the modifications that increase nowadays, and the material used is believed to be the foremost point in the characteristic and application of the material. On the other hand, when used in the form of powder or solid, there are various challenges associated with its application, including the complications of separation, susceptibility to saturation, and the issue of leaching. Hence, one of the solutions is to develop core–shell-based materials in the form of membranes or incorporate them into a membrane matrix. Due to its low cost and practicality, membrane technology emerges as an efficient method. Various membrane modifications and configurations, such as core–shell-based membrane matrix, as membrane filler, or as coating layer, have been carried out to achieve excellent filtration performance. Nanofiber membrane which adopts a core–shell configuration in its matrix has shown better performance. Furthermore, fouling is a prevalent problem for membranes that can be addressed by using fillers made from core-shell structured materials. The enhanced filler dispersion and matrix stability lead to the high permeation flux and selectivity. Nevertheless, the particular synthesis and preparation conditions of the material remain a limitation, particularly when it comes to scaling up its application. This review focuses on core–shell-based material as a catalyst and adsorbent, encompassing variations in their core materials, synthesis methods, and their application in membranes which involves the core–shell configuration of membranes, the synthesis process, and the performance of the membrane with the presence of the structured material as a matrix, filler, and others. In addition, comprehensive applications of the core–shell-based membrane as a photocatalytic and adsorptive membrane in wastewater treatments are discussed. Furthermore, the review outlines a forward-looking perspective on the potential evolution of core-shell-based membranes, underscoring their continued significance in advancing wastewater treatment methodologies.