Temperature Driven Evolution of Alumina Nanowhiskers in Aluminum Intercalated Layered Graphene Oxide

Abstract Layered graphene oxide (GO) has attracted considerable attention for a wide range of applications, from optoelectronic devices to solar cells, where performance can be significantly enhanced through elemental intercalation. In this work, we demonstrate the temperature-dependent hydrothermal growth of Al-intercalated GO (Al@GO), achieved through the chemical reaction of GO and aluminum acetylacetonate, resulting the formation of Al–O–C bonds, as confirmed by X-ray photoelectron spectroscopy. X-ray diffraction measurements reveal the transformation of GO to reduced GO (rGO) at 180 °C, while scanning electron microscopy indicates the formation of layered GO with tortuous porous morphology. High-resolution transmission electron microscopy, along with energy-dispersive X-ray spectroscopy, further confirms the discrete evolution of alumina nanowhiskers, predominantly in the γ-phase, as evidenced by selected area electron diffraction. Density functional theory calculations support the formation of Al–O–C bonds in Al@GO, while Al intercalation induces an indirect-to-direct bandgap transition in GO.