Open AccessThe Galvanic Protection of an Electrochemically Deposited Photocatalytic Au/FeAu Multilayered Nanowire—TiO2 Composite
Author(s) -
Savidra Lucatero,
Elizabeth J. Podlaha
Publication year - 2021
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abdfe3
Subject(s) - materials science , photocatalysis , nanowire , photocurrent , composite number , chemical engineering , water splitting , catalysis , galvanic cell , alloy , layer (electronics) , dielectric spectroscopy , electrode , nanotechnology , composite material , metallurgy , electrochemistry , chemistry , optoelectronics , biochemistry , engineering
Gold nanoparticles on the surface of TiO 2 is a useful water splitting photocatalyst but its performance can degrade in an oxygenated environment. To deter this degradation a novel composite photocatalyst consisting of electrodeposited Au/FeAu nanowires dispersed onto electrochemically deposited TiO 2 on top of a stainless steel substrate was shown to inhibit degradation effects observed during water oxidation in base. A step in illumination and impedance modulated photocurrent spectroscopy (IMPS) provided a quantitative measure of the photoactivity and fate of minority carriers (holes, h + ) in fresh and aged composites. The photogenerated current and h + flux to the electrode surface of fresh catalyst significantly decayed within a period of 120 d in the Au/TiO 2 system, whereas in the Fe-containing composite, these performance parameters were maintained for an extended period of time. Composite photocatalysts with Au/FeAu nanowires exhibiting modulations in porosity and composition of the alloy segment were also investigated. The catalyst photoactivity was adversely affected by either decreasing porosity and/or increasing Fe content within the alloy layer of nanowires combined with TiO 2 .