General fabrication of metal oxide nanoparticles modified graphene for supercapacitors by laser ablation

Metal oxide nanoparticles (MONPs)-graphene composites are highly valued candidate electrode materials for electrochemical supercapacitor (SC). Here, we described the development of a versatile approach for fabricating SC electrodes by impregnating MONPs (M = Ti, Ni, Sn) synthesized by laser ablation in liquid on laser-induced graphene (LIG). A typical SnO₂/LIG micro-supercapacitor (MSC) delivers an area-specific capacitance of 18.58 mF cm⁻² at a scan rate of 10 mV s⁻¹, which is 5.2 times greater than the unmodified LIG. Moreover, the MSC exhibits long-life cycling stability (retaining 82.15% of specific capacitance after 5000 cycles) and good mechanical flexibility (specific capacitance is reduced by 5% at bending angle of 150°). MONPs and LIG are prepared using the same laser processing system, and no chemical ligands or reducing agents used in the synthesis process, which is cost-effective and green. This simple and straightforward method provide a highly operable solution for the large-scale preparation of MSC.