Synthesis of a-Ga2O3 by Water Oxidation of Metallic Gallium as a Photocatalyst for CO2 Reduction with Water

We have succeeded to synthesize gallium oxide consisting of a-phase (alpha-Ga2O3) with the calcination of GaOOH obtained by a direct reaction of liquid Ga metal with water for the first time and found that a-Ga2O3 exhibits photocatalytic activity for CO2 reduction with water and water splitting as well. The calcination above 623 K converted GaOOH to alpha-Ga2O3, and the samples calcined at 723-823 K were well crystallized to a-Ga2O3 and promoted photocatalytic CO2 reduction with water, producing CO, H-2, and O-2. This is observed for the first time that a-Ga2O3 without a cocatalyst has shown very high photocatalytic activity for the conversion of CO2 to CO.

Automated summary

The synthesis of α-phase (alpha-Ga2O3) with high photocatalytic activity for CO2 reduction and water splitting was achieved for the first time by calcination of GaOOH obtained from a direct reaction of liquid Ga metal with water. The conversion of GaOOH to α-Ga2O3 at temperatures above 623 K led to well-crystallized samples at 723-823 K, promoting the photocatalytic CO2 reduction with water to produce CO, H2, and O2. This study demonstrated the high photocatalytic activity of α-Ga2O3 for converting CO2 to CO without a cocatalyst.