RESUMO
A highly symmetrical, 24-faceted, concave BiVO4 polyhedron was fabricated, bounded by multiple high-index {012}, {210}, {115}, and {511} facets, exhibiting impressive photocatalytic O2 evolution for water oxidation in the absence of any cocatalysts, more than two orders of magnitude higher than that of the bulk materials. The corresponding apparent quantum yield (AQY) of O2 evolution was measured as high as 30.7% under 420 nm light irradiation, a new record AQY for BiVO4. The high-index facets are not only energetically favorable for water dissociation, but also exhibit an obvious reduction in the overpotential (0.7-1.0 V) for the oxygen evolution reaction.
RESUMO
Correction for 'Direct Z scheme-fashioned photoanode systems consisting of Fe2O3 nanorod arrays and underlying thin Sb2Se3 layers toward enhanced photoelectrochemical water splitting performance' by Yong Zhou et al., Nanoscale, 2019, DOI: 10.1039/c8nr08292h.
RESUMO
An elegant Z-scheme-fashioned photoanode consisting of Fe2O3 nanorod arrays and underlying thin Sb2Se3 layers was rationally constructed. The photocurrent density of the Sb2Se3-Fe2O3 Z-scheme photoanode reached 3.07 mA cm-2 at 1.23 V vs. RHE, three times higher than that of pristine Fe2O3 at 1.03 mA cm-2. An obvious cathodic shift of the photocurrent onset potential of about 200 mV was also observed. The transient photovoltage response demonstrates that the suitable band edges (ECB â¼ -0.4 eV and EVB â¼ 0.8 eV) of Sb2Se3, match well with Fe2O3 (ECB â¼ 0.29 eV and EVB â¼ 2.65 eV), permitting the photoexcited electrons on the conduction band of the Fe2O3 to transfer to the valence band of Sb2Se3, and recombine with the holes therein, thus allowing a high concentration of holes to collect in the Fe2O3 for water oxidation. The transient absorption spectra further corroborate that the built-in electric field in the p-n heterojunction leads to a more effective separation and a longer lifetime of the charge carriers.
RESUMO
Integration of FexS electrocatalysts and simultaneously generated interfacial oxygen vacancies (VO) was designed to promote the water splitting performance of Fe2O3 photoanodes, in which a synergistic effect remarkably reduces the carrier recombination, increases the number of active sites, and facilitates the photogenerated holes to participate in water oxidation.