Nanoengineered Laser-Induced Graphene-Ni Composite Membranes for Heterogeneous Catalysis: A Strategy for Removal of Carbamazepine and Ciprofloxacin

Membrane technology is a promising alternative for water purification due to its compact process and high efficiency for micropollutant removal. However, high-pressure requirements and fouling remain challenges, affecting cost and membrane lifespan. Electroconductive ultrafiltration (UF) membranes have shown the potential for efficient pollutant removal via an electrostatic rejection; however, they have inferior performance for electrochemical oxidation in the absence of catalysts. In the present work, laser-induced graphene-nickel (LIGNi) based electroconductive catalytic porous surfaces such as electrodes, filters, and UF membranes are fabricated by optimizing the Ni concentration in a single step with CO2 infrared laser and used for emerging contaminants removal. LIGNi composite surfaces exhibit high catalytic properties and electrical conductivity, with a surface charge density of 8.18 × 104 μC cm–2, which is twice that of control LIG. These composites enhance Carbamazepine and Ciprofloxacin removal, achieving ∼85% and ∼80% removal, respectively, at 500 L m–2 h–1 flux and 5 V in flow-through filtration due to effective heterogeneous catalysis. In cross-flow filtration, removal exceeds 90% via electrostatic rejection, electrosorption, and electrochemical oxidation. The electrocatalytic properties of electroconductive membranes enable multiple pollutant degradation mechanisms, including direct and indirect oxidation. Integrating LIGNi composite membranes facilitates simultaneous filtration and degradation in low-pressure ultrafiltration, reducing the carbon footprint and promoting sustainability.