Porous materials including polymeric and inorganic membranes are important and widely used in various industries. Controlling the pore size and pore distribution in porous materials is the major focus in this field. In this study, a novel copper-catalyzed template dissolution approach using ferric oxyhydroxide (FeOOH) as nano-templates was introduced for the preparation of ultraporous polymeric membrane. Compared to typically used acid dissolution method, this approach accelerated the removal of FeOOH by 30 folds. The reduction of ferric by copper into ferrous weakened the Fe-O bonds in FeOOH hence leading to fast dissolution of the nanomaterials. The effectiveness of copper-catalyzed FeOOH dissolution was affected by the concentration of acid and copper ions as well as the type of anions present in the dissolution solution. Membranes fabricated via FeOOH-templating approach were evaluated for microalgae dewatering application and showed 8�21 higher solution flux than their corresponded nanocomposite membrane. The enhancement was attributed to the elevation of membrane porosity by 1�4 and the creation of more interconnected pore system. The best membrane, M1.0 exhibited the highest porosity of 94 and achieved the best microalgae solution flux of 57.7 L·m�2·h�1. The outcomes of this study confirmed the viability of copper-catalyzed approached in accelerating the formation of ultraporous materials and demonstrated the potential of such materials in microalgae dewatering application. © 2022 Elsevier B.V.