Ag@Sr2TiO4/Bi5O7I Heterostructured Composite for Solar-Driven Photoelectrochemical Analysis

摘要

PlasmonicAg nanoparticles were photodeposited on the surface of Sr2TiO4 and Bi(5)O(7)wI to fabricate a photoelectrode for photoelectro-chemical measurements. The Ag@Sr2TiO4/Bi5O7I heterostructured composite exhibited extended visible-light absorption, surface plasmonic resonance, improved photocurrent response, decreased film resistance, and increased donor density. The semiconducting properties of these samples, including the conduction and valence band levels, flatband potential, and donor density, were obtained from AC impedance spectra, a Mott-Schottky analysis, and a linear current-potential scan under the illumination of a xenon lamp with an AM1.5 filter to simulate AM 1.5-type solar irradiation. The Mott-Schottky analysis clearly displayed the formation of a p-n junction at the interface of the Ag@Sr2TiO4/Bi5O7I composite, which is advantageous to the electron transfer. Thanks to its interfacial p-n junction and the surface plasmonic resonance effect of Ag on the Ag@Sr2TiO4/Bi5O7I composite, this photoelectrode can serve as a potential candidate for solar-driven photoelectrochemical applications. (C) 2018 The Electrochemical Society.