Laser-Induced Graphene and Graphene Oxide for Environmental Applications

Laser-induced graphene and graphene oxide (LIG/LIGO) are synthesized via a scalable, one-step laser fabrication process directly from polymeric substrates. Owing to their high electrical conductivity, porous architecture, and tunable surface chemistry, these materials are well-suited for environmental sensing and selective pollutant removal. Two representative applications are discussed below.

The detection and monitoring of lithium ions are becoming increasingly vital owing to the rising demand for clean energy sources. In the first study, we introduce an in situ fabrication approach for composite electrodes that combines LIG with manganese oxides for ion-selective electrochemical sensing. A novel manganese–oxide electrode is fabricated through the in situ transformation of an MnCl₂ precursor during the LIG laser process, and its performance is compared with LIG electrodes that incorporate pre-synthesized MnO₂ particles. Electrochemical analysis reveals that the LIG/MnOₓ electrodes formed via in situ conversion exhibit superior ion selectivity compared to those containing pre-synthesized MnO₂.

In the second study, we developed a membrane based on LIGO derived from a polyimide substrate via controlled oxidation in the presence of water during laser processing. The resulting LIGO was mixed with dopamine (DA) and polyethyleneimine (PEI), thereby forming a stable LIGO–DA/PEI composite membrane through covalent cross-linking. Membrane performance was evaluated using copper-removal efficiency and water-flux measurements and compared with membranes prepared from commercially available GO to elucidate the influence of GO properties on purification performance.

These two applications provide a promising platform for the future development of LIG and LIGO in the areas of sensing and purification.