ABSTRACT Dimensional shrinkage and morphology modulation of nanostructured β‐Ga 2 O 3 play a crucial role in regulating its photocatalytic and cold‐emission performances. In this work, β‐Ga 2 O 3 nanostructures were synthesized via calcination of gallium oxyhydroxide, prepared through a simple chemical route. Morphological control was achieved using polyvinylpyrrolidone (PVP) as a shape‐directing agent, which suppresses particle agglomeration and promotes controlled growth along specific crystallographic facets. In addition to conventional structural and morphological characterizations, the photocatalytic performance of Ga 2 O 3 systems was evaluated by time‐resolved UV–Vis absorption spectroscopy during degradation of eosin B (EB) dye under UV irradiation. The porous β‐Ga 2 O 3 nanoflakes exhibited a significantly larger effective surface area and enhanced UV–Vis light absorption compared to irregularly shaped, agglomerated Ga 2 O 3 . Consequently, the nanoflake‐based β‐Ga 2 O 3 achieved a photodegradation efficiency of ∼99% within 30 min of UV‐exposure, markedly superior to that of the agglomerated Ga 2 O 3 counterpart (∼30%). Furthermore, the β‐Ga 2 O 3 nanoflakes demonstrated enhanced cold emission characteristics, attributed to their high aspect ratio, porous morphology, and increased density of emission sites. Overall, this study presents a facile, low‐cost, and environmentally benign strategy for tailoring the morphology of Ga‐based oxide nanostructures, enabling superior photocatalytic activity for wastewater remediation and improved cold‐cathode emission performance compared to commercially available gallium oxide.
Das et al. (2026) studied this question.