Fabrication, Characterization, and Photoelectrochemical Properties of Cu-Doped PbTiO3 and Its Hydrogen Production Activity

Abstract

We report herein the fabrication of visible-light responsive n-type PbTiO3 by a combustion method and p-type Cu-doped PbTiO3 by an impregnation method to improve hydrogen production activity. Copper was doped into the PbTiO3 lattice up to 1wt%; any further increase in the loading resulted in the formation of CuO on the surface of the sample. Photoluminescence confirmed that 1wt% Cu-doped PbTiO3 effectively suppressed the defects in PbTiO3, which helped to reduce the recombination rate of the photoinduced charge carriers. The prepared PbTiO3 photocatalyst behaves as an n-type semiconductor, whereas 1wt% Cu-doped PbTiO3 behaves as a p-type semiconductor. The photocatalytic hydrogen production activity of PbTiO3 increased with increasing Cu content up to 1wt% and thereafter decreased upon further loading. The 1wt% Cu-doped PbTiO3 sample showed higher activity for hydrogen liberation than pristine PbTiO3 (2.5times) and all of the other CuO-loaded samples(.) The energy conversion efficiency of 1wt% Cu-doped PbTiO3 was 5.95% for hydrogen production under visible-light irradiation. The enhanced hydrogen production activity of Cu-doped PbTiO3 was discussed on the basis of optimum copper doping, photoluminescence intensity, and their band-edge positions. However, the higher activity of CuO-loaded (>1wt%) PbTiO3 relative to that of neat PbTiO3 is perhaps a result of the extensive light absorption properties of the CuO nanoparticles, which help to generate more electron-hole pairs on the surface.