Mesoporous mixed-phase Ga 2 O 3 : Green synthesis and enhanced photocatalytic activity

Abstract Mesoporous mixed-phase Ga 2 O 3 was synthesized by calcining the GaOOH precursor. The composition, crystal phase and microstructures of Ga 2 O 3 were characterized in detail. The phase composition of the as-prepared Ga 2 O 3 depended on the calcination temperature and the mixed-phase Ga 2 O 3 was obtained at 600–700 °C. As compared to the pure-phase α-Ga 2 O 3 and β-Ga 2 O 3 , the mixed-phase Ga 2 O 3 exhibited an enhanced photocatalytic property for the degradation of metronidazole solution. The heterojunction in the mixed-phase Ga 2 O 3 was beneficial to the separation of photogenerated electrons and holes. Moreover, the mixed-phase Ga 2 O 3 possessed mesopore structure, which increased more reaction sites and was in favor of the contact of metronidazole molecules with reaction sites. The recycling experiments show that the mixed-phase Ga 2 O 3 has good stability and can be separated easily from the reaction system.