Photoelectrochemical study of potentiodynamically anodized H<SUB>2</SUB>-reduced PbTiO<SUB>3</SUB> + PbO mixed-oxide electrode in 0.1 M NaOH + 0.1 M Na<SUB>2</SUB>SO<SUB>4</SUB>

The mechanism of lead oxide formation and the enhanced photoresponse produced by potentiodynamic anodization of the H2-reduced surface of a PbTiO3 + PbO sintered pellet were investigated in the potential region from -1.25 to +2.35 V/SCE in 0.1 M Na2SO4 + 0.1 M NaOH at 80&#176;C. The anodized electrode was characterized by X-ray diffraction, UV-visible reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy with energy dispersive X-ray analysis and various photoelectrochemical techniques. An 11-fold increase in solar to electrical power conversion efficiency and an enhanced quantum yield of 9% in 0.1 M Fe(CN)3-/4-6 redox electrolyte (pH 9.2) was observed with the H2-reduced PbTiO3 + PbO electrode anodized for 30 min compared with the unanodized H2-reduced PbTiO3 + PbO electrode