Carbon-doped In 2O 3 films for photoelectrochemical hydrogen production

Abstract

Carbon-doped In 2O 3 films were synthesized by spray pyrolysis and evaluated for photoelectrocatalysis. All C-doped films showed cubic structure, and XPS confirmed carbon's presence and content. 13C SSNMR showed the presence of carbonate-type species. C-doped In 2O 3, compared to undoped, showed increased absorption in the 350–500 nm range with a red shift in the band gap transition. The photoactivity was evaluated under near-UV and visible light irradiation. The C-doped films exhibited photocurrent densities up to 1 mA/cm 2, with a high contribution (40%) from visible light irradiation. Under the same irradiation conditions, C-doped In 2O 3 produced much greater photocurrent densities than the undoped films. Photocurrent densities of the C-doped films were determined as a function of the dopant source, its concentration, and film thickness. These results indicate the potential for further development of In 2O 3 photocatalysts, and provide useful information towards understanding the structure and enhanced photoelectrochemical properties of these new materials.