Flexible supercapacitors based on laser-induced graphene (LIG) have emerged as a promising solution for scalable and cost-effective energy storage applications owing to their ease of fabrication and eco-friendly nature. However, the role of aqueous electrolytes in energy storage and conduction in thin-film electrodes has not yet been well explored. This study focused on optimizing the laser parameters, including the laser speed and power, to enhance the properties of LIG electrodes while investigating the influence of different aqueous electrolytes on electrochemical performance. The optimized laser parameters were a laser speed of 180 mm s⁻¹ and power of 40 W. The optimized electrodes were characterized using Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and Brunauer–Emmett–Teller surface parameter study. The characterization results revealed that the optimized LIG was highly defective, with an I _D/I _G ratio of 2.38, surface area of 25.146 m² g⁻¹, and pore diameter of 13.74 nm. Supercapacitors with H₂SO₄ exhibited a superior areal capacitance (34 mF cm⁻²) because of their high ionic conductivity, redox activity, and efficient H⁺ ion transport (hydrated radius: 2.8 Å). Na₂SO₄ and KOH showed lower capacitance (15 and 17 mF cm⁻²), limited by larger Na⁺ and K⁺ hydrated radii. The defect density increased fivefold compared to the benchmarks, enhancing the electrochemical performance eightfold. These findings underscore the role of laser parameter optimization in improving LIG-based energy-storage devices.

Molybdenum disulfide (MoS₂) is a transition metal dichalcogenide (TMDCs) having versatile properties and plays a great role in the photodegradation of organic dyes. MoS₂ also finds applications in diverse fields such as catalysis, electronics, and nanomedicine transportation. MoS₂ can be prepared by using chemical and physical methods such as hydrothermal, solvothermal, and chemical vapour deposition methods. The preparation method employed can produce subtle but significant changes in the morphology. To increase the efficiency of MoS₂, it can be combined with different materials to produce composites that improve the photodegradation efficiency of MoS₂. The various methods of preparation, the morphology of MoS₂, and photodegradation activity of the MoS₂-based nanocomposites are briefly discussed in this review.