Non-Covalent Immobilization of Lanthanum Phthalocyanine on Graphene Oxide: Structural, Spectroscopic, and Thermal Characterization

Abstract

A lanthanum phthalocyanine-graphene oxide (LaPc-GO) nanohybrid was prepared via a non-covalent immobilization strategy and systematically characterized to elucidate its structural, spectroscopic, morphological, and thermal properties. The effective integration of the LaPc macrocycle onto the graphene oxide surface was examined using UV-Vis, FT-IR, Raman, XRD, XPS, SEM-EDX, and TG-DTA techniques. The spectroscopic results indicate that the intrinsic electronic and vibrational characteristics of LaPc are preserved after hybrid formation, while subtle band shifts and intensity variations suggest strong interfacial interactions with the GO surface. Structural and morphological analyses reveal a homogeneous dispersion of LaPc on the graphene oxide sheets without noticeable phase segregation or aggregation. Thermal analysis further demonstrates that the LaPc-GO nanohybrid exhibits enhanced thermal stability compared to pristine graphene oxide, as evidenced by increased decomposition temperatures and higher residual mass. These findings confirm the structural integrity and interfacial coupling within the LaPc-GO nanohybrid and highlight its potential for applications requiring thermally stable and it-conjugated functional materials.