Fabrication of Dual‐Functional MXene@NiCo2S4 Composites with Enhanced Nonlinear Optical and Electrochemical Properties

Abstract The design and synthesis of multifunctional nanomaterials have attracted considerable attention for expanding the range of practical applications. Herein, a metal–organic framework (MOFs)‐derived NiCo 2 S 4 attached to MXene is rationally designed and constructed for an optical limiter and supercapacitor. The MOF‐derived NiCo 2 S 4 enhances the tendency of hydroxyl groups on the MXene surface to attract metal ions, resulting in the formation of sulfur vacancies. Moreover, MXene offers a high specific surface area to facilitate the rapid complexation of charge carriers. The resultant MXene@NiCo 2 S 4 (MX@NCS) exhibits markedly enhanced nonlinear optical (NLO) and electrochemical properties through synergistic interactions between the components. The NLO properties can be further optimized by adjusting the amount of MX@NCS powder dispersed in methyl methacrylate (MX@NCS) 2–6 /PMMA) by using the Z‐scan technique. Specifically, the (MX@NCS) 4 /PMMA exhibits the strongest reverse saturable absorption (RSA) and self‐defocusing effects at 100 µJ with β = 3.87 × 10 2 cm·GW −1 and γ = −5.94 × 10 −4 cm 2 ·GW −1 . Concurrently, the constructed supercapacitor shows a superior energy density of 51.21 Wh·kg −1 at a power density of 863.65 W·kg −1 . Notably, the present study indicates a novel strategy to explore the application of materials in the development of efficient optical limiter and supercapacitor technologies.