Photocatalytic degradation of organic pollutants by shape selective synthesis of β-Ga2O3 microspheres constituted by nanospheres for environmental remediation

Abstract

A potential single crystalline photocatalyst β-Ga₂O₃ with unique spherical morphology has been synthesized using a surfactant assisted hydrothermal process. Organic additive triblock co-polymer pluronic F127 was used as a soft template. The morphology of the material was investigated using scanning electron microscopy and it was confirmed that the nanospheres self-assembled to form microspheres with diameters in the range ∼1–3 μm. The crystal phase and chemical composition of the β-Ga₂O₃ microspheres were revealed by X-ray diffraction and X-ray photoelectron spectroscopy. Structural characterization exhibits the monoclinic phase of the microspheres with preferential growth along the [111] direction. A plausible mechanism has been proposed to understand the formation of microspheres. The optical absorbance spectrum showed an intense absorption feature in the UV spectral region with a bandgap energy of 4.6 eV. The Brunauer–Emmett–Teller specific surface area was found to be 82 m² g⁻¹. The photocatalytic activity of the material has been investigated for the degradation of model organic pollutants Rhodamine B and methylene blue under ultraviolet light irradiation. The photocatalytic mechanism towards the degradation of organic dyes has also been proposed.