In Situ Synthesis and Characterization of Conductive Hybrid Composites Using Functionalized 3D Molybdenum Disulfide Nanoflowers

We obtained 3D nanoflowers of MoS₂ (3D-MoS₂) with an average size of 1–3 µm synthesized by a one-step hydrothermal method, the "flower-shape" being composed of several petal-like sheets with a thickness of about 19 nm. The 3D nanoflowers underwent functionalization with diethyl[2-hydroxy-2-(thiophen-3-yl)ethyl]phosphonate and 2-tiophene carboxylic acid. P3HT/MoS₂ composites were synthesized by Grignard metathesis using a 2,5-dibromo-3-hexylthiophene/MoS₂ weight ratio of 1:0.05. As a reference, the P3HT/MoS₂ composites were also synthesized with unfunctionalized 3D-MoS₂. The P3HT/MoS₂ composites were characterized by FTIR, XRD, TEM, ¹H NMR, UV–Vis, TGA, and cyclic voltammetry. We studied the influence of 3D-MoS₂ nanoflowers functionalized with phosphonic and carboxyl groups on the properties of the P3HT/MoS₂ composites. The addition of functionalized 3D-MoS₂ in the P3HT/MoS₂ composites improved the percentage of HT dyads and the definition of shoulders in the dyad signal, indicating a better arrangement of the polymeric chains in the P3HT/3D-MoS₂ functionalized composites. In addition, the functionalization of the 3D-MoS₂ white phosphonic group increased the conjugation length, the percentage of crystallinity, and the conductivity. Likewise, the P3HT/MoS₂ functionalized composites showed a decrease in the energy gap compared to P3HT. The functionalization of the 3D-MoS₂ was successfully carried out, and a close interaction between the P3HT and 3D-MoS₂ was determined. We achieved the in situ synthesis of P3HT/MoS₂ composites by Grignard metathesis using functionalized 3D-MoS₂ obtained by the hydrothermal method. We compared two functionalization groups with 3D-MoS₂ and their subsequent polymerization with P3HT. Our work provides evidence for a better performance in composites functionalized with a phosphonate group because a phosphonic anchor provides strong electronic coupling with the 3D-MoS₂. The above makes this material suitable for applications in flexible electronics photosensors, electrochromic devices, photocatalysis, and harvesting energy material in solar cells.