Enhanced thermal assisted photocatalysis reduction of carbon dioxide over a Fe2−xGaxO3 solid solution

Abstract

α-Fe₂O₃ is considered as a promising photocatalytic material due to its low cost, easy availability, and excellent visible light absorption. However, its photocatalytic efficiency is still limited by fast charge recombination. Herein, we report the introduction of Ga in the form of Fe_2−xGa_xO₃ solid solution and the corresponding effect on the electronic structure and photoelectrical activity. The introduction of Ga, suggested by the results of theoretical calculation, reverses the electron spin state in the conduction band, which is beneficial to the suppression of carrier recombination. The above conclusion is further supported by the experimental results. Among the range of materials synthesized, Fe_1.96Ga_0.04O₃ displays the best photothermal activity towards CO₂ reduction, in which the CO evolution rate is about 2.4 times that of pure Fe₂O₃. This work provides an alternative way to improve the activity of α-Fe₂O₃.