Laser-Induced Synthesis of ZnO/Graphene Composites with a Porous Structure for Supercapacitors

The growing demand for advanced energy storage systems has intensified the exploration of materials for supercapacitors (SCs). Zeolitic imidazolate frameworks (ZIFs) and their derivatives have emerged as promising candidates due to their unique structural and performance characteristics. This study demonstrates a laser-induced method for synthesizing ZnO/graphene composites with a porous structure derived from dopamine-coated ZIF-8. The simultaneous laser-induced carbonization of dopamine to form graphene and decomposition of ZIF-8 to generate ZnO resulted in a synergistic porous structure, significantly enhancing the charge transport ability and electrochemical performance of the ZnO/graphene composite. Following optimization, the ZnO/graphene composite electrode (ZPL-9) achieved a high specific capacitance of 331.8 mF cm-2 at a current density of 1 mA cm-2. Furthermore, the electrode retained 87% of its capacitance after 10,000 cycles at 5 mA cm-2, highlighting its robust cycle stability. A button-type symmetric SC was successfully assembled using the ZPL-9 electrode, achieving an energy density of 5.2 mu Wh cm-2 at a power density of 299.04 mu W cm-2. The study not only provides insights into the application of MOF-based materials in energy storage but also demonstrates the potential of laser-induced methods for synthesizing high-performance electrode materials.