Sustainable carbonaceous materials-based catalytic membranes for organic wastewater treatment: Progress and prospects

Catalytic membrane, as a cutting-edge hybrid technology, is promising for organic wastewater treatment not only because of the excellent removal efficiency for various organic pollutants, but also because of the mitigation of membrane fouling. However, some challenges persist, including the relatively high fabrication costs of membranes, the high possibility of metal ions leaching from membrane structures, and the poor renewability of synthetic materials, which significantly restrict more widespread application. To address these issues, carbonaceous materials (e.g., biochar, activated carbon, carbon nanotubes, graphene, graphene oxide) are renewable and environmentally friendly materials that inherently have large surface areas, high porosity, and tuneable surface functional groups that can be employed as excellent alternatives in catalytic membranes. In this review, various methods (e.g., blending, in-situ growth, interfacial polymerization, and layer-by-layer assembly) for the fabrication of carbonaceous materials-based membranes are comprehensively summarized and discussed. Subsequently, the integration of catalytic membranes in different processes, whether individually (e.g., photocatalytic process, advanced oxidization process, and electrocatalytic process) or hybridized (e.g., photoelectrochemical process, photo-assisted advanced oxidization process), is assessed. In addition, various carbonaceous materials-based catalytic membranes implemented for the remediation of wastewater are critically discussed. Furthermore, the existing challenges are described, and further research recommendations are proposed. This review is expected to be beneficial for advancing the development of carbonaceous materials-based catalytic membranes for practical decontamination of organic wastewater.