TY - JOUR
T1 - Photoassisted Electrolysis of Water by Ultraviolet Irradiation of an Antimony Doped Stannic Oxide Electrode
AU - Wrighton, Mark S.
AU - Morse, David L.
AU - Ellis, Arthur B.
AU - Ginley, David S.
AU - Abrahamson, Harmon B.
PY - 1976/1/1
Y1 - 1976/1/1
N2 - Products, stoichiometry, and the stability of the photoelectrode show that the n-type semiconductor Sb-SnO2, as a single crystal, can serve as the photoreceptor in a photoelectrochemical cell to electrolyze H2O to H2 and O2. The O2 is evolved at the irradiated Sb-SnO2 electrode, and the H2 is evolved at the Pt electrode of the cell. Substantial photocurrents are obtained when the applied potential (+ lead to SnO2) exceeds ~0.5 V, and light of greater energy than the 3.5 eV band gap of SnO2 is required to observe photoeffects at 25°. Importantly, increasing the temperature results in a measurable shift to lower energy for the onset of the photoeffects. The quantum efficiency for electron flow at 254 nm at 0.0 V vs. SCE in 1.0 M NaOH is 0.27 ± 0.03, and the wavelength response curve and current-voltage curve show that the quantum efficiency for electron flow is near unity at higher energy excitation wavelengths and slightly higher applied potentials. The photocurrent produces H2 with >90% efficiency. Experiments with H218O show that the O2 produced is not due to decomposition of SnO2, and additionally, stability of the SnO2 photoelectrode has been determined by constant weight before and after prolonged irradiation.
AB - Products, stoichiometry, and the stability of the photoelectrode show that the n-type semiconductor Sb-SnO2, as a single crystal, can serve as the photoreceptor in a photoelectrochemical cell to electrolyze H2O to H2 and O2. The O2 is evolved at the irradiated Sb-SnO2 electrode, and the H2 is evolved at the Pt electrode of the cell. Substantial photocurrents are obtained when the applied potential (+ lead to SnO2) exceeds ~0.5 V, and light of greater energy than the 3.5 eV band gap of SnO2 is required to observe photoeffects at 25°. Importantly, increasing the temperature results in a measurable shift to lower energy for the onset of the photoeffects. The quantum efficiency for electron flow at 254 nm at 0.0 V vs. SCE in 1.0 M NaOH is 0.27 ± 0.03, and the wavelength response curve and current-voltage curve show that the quantum efficiency for electron flow is near unity at higher energy excitation wavelengths and slightly higher applied potentials. The photocurrent produces H2 with >90% efficiency. Experiments with H218O show that the O2 produced is not due to decomposition of SnO2, and additionally, stability of the SnO2 photoelectrode has been determined by constant weight before and after prolonged irradiation.
UR - https://www.scopus.com/pages/publications/0011831267
U2 - 10.1021/ja00417a009
DO - 10.1021/ja00417a009
M3 - Article
AN - SCOPUS:0011831267
SN - 0002-7863
VL - 98
SP - 44
EP - 48
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 1
ER -