Geopolymer armor-reinforced composite membranes for efficient oil–water separation and dye degradation

Developing efficient dual functional membranes through simple methods to remove various water pollutants remains challenging. Herein, a dual functional geopolymer/copper mesh membrane (GM/CM) was fabricated by one-step coating for oil–water separation and dye degradation. The geopolymer coating, serving as armor, improved hydrophilicity and pore structure, enabling rapid pollutant adsorption and degradation via advanced oxidation processes (AOPs) while inhibiting copper ion leaching. The GM/CM had a water flux of 4936 L m −2 h −1 bar −1 and demonstrated a separation efficiency of over 99 % for five different oil–water emulsions. Copper ions in GM/CM, with multiple valences, could efficiently catalyze reactive oxygen species production from H 2 O 2 . In batch mode, the GM/CM + H 2 O 2 system removed 98.48 % of methylene blue (MB) in water with 1 O 2 as the primary active species. Multiple anions had no significant impact on the degradation efficiency of the GM/CM + H 2 O 2 system. In filtration mode, the GM/CM + H 2 O 2 system achieved over 98 % removal of MB within a continuous 180 min period. Compared to other membranes, GM/CM had both high flux and competitive removal efficiencies. Moreover, due to the ion exchange and chelating effects of the geopolymer armor, the leaching concentration ratio of copper ions was two orders of magnitude lower than that in the unarmored catalyst CM + H 2 O 2 system, and significantly below the standard limit and the results reported in other literature. Overall, this work shows the potential application of GM/CM in water treatment and offers a new method for convenient preparation of dual functional membranes.