Solvent-Free Hydrothermal Synthesis of Network-Like Graphene Quantum Dots (GQD) Nano Particle and Ultrasonic TiO2/GQD Nanocomposite

The enhancement of solar cell efficiency, is required to use materials of a good electrical properties. In this work, the graphene quantum dots (GQD) created from starch as precursor has been performed in single pot using a hydrothermal process. The TiO2/GQD nano-composite was prepared using an in-depth ultrasonic technique to use as a semiconductor in a solar cell. The investigated using techniques such as: FT-IR, FE-SEM, XRD, Raman spectrum. Additionally, the synthesis and the characterization of novel porphyrin derivatives with amide, were designed as sensitizers in dye-synthesized solar cells (DSSCs). Five derivatives were synthesized via a one-pot reaction of porphyrin with amines, and their optimal yield was obtained under various conditions. The synthesized dyes were characterized using techniques such as melting point analysis, mass spectroscopy, FT-IR, 1H,13C-NMR and ESI-Mass. The obtained results demonstrated that the 6b dye exhibited with the high efficiency of 1.86 % at AM 1.5, followed by 6a with 1.82 %, 8a with 1.34 %, and 8b with 1.14 %, as compared to the control cell (N719) with an efficiency of 5.4 %.