Synthesis of meso-porous α-Ga 2 O 3 from liquid Ga metal having significantly high photocatalytic activity for CO 2 reduction with water.

We have succeeded in synthesizing meso-porous α-Ga 2 O 3 which shows significantly high photocatalytic activity for CO 2 reduction with water. The sample was synthesized by hydroxidation of liquid Ga metal in water to obtain GaOOH and Ga(OH) 3 , followed by the calcination of the mixed hydroxides at 773 K for 1 hour which converted them to meso-porous α-Ga 2 O 3 . The nano-pores remained as the trace of the evaporation of water produced by the oxidation of the hydroxides during the calcination. The photocatalytic activity of the synthesized meso-porous α-Ga 2 O 3 for CO 2 reduction with water was as high as or higher than previous studies using various types of Ga 2 O 3 with and without cocatalysts.