Open AccessTwo-Dimensional Restructuring of Cu2O Can Improve the Performance of Nanosized n-TiO2/p-Cu2O Photoelectrodes under UV–Visible Light
Author(s) -
Antonio Rubino,
Robertino Zai,
Pier Giorgio Schiavi,
Alessandro Latini,
Francesca Pagnanelli
Publication year - 2021
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.1c13399
Subject(s) - materials science , visible spectrum , irradiation , photocatalysis , octahedron , photoelectrochemistry , water splitting , nanoparticle , electrode , nanotechnology , chemical engineering , optoelectronics , electrochemistry , catalysis , crystallography , crystal structure , chemistry , physics , biochemistry , nuclear physics , engineering
p-Cu 2 O/n-TiO 2 photoanodes were produced by electrodeposition of octahedral p-type Cu 2 O nanoparticles over n-type TiO 2 nanotubes. The photoresponse of the composite p-n photoanodes was evaluated in photoelectrochemical cells operating at "zero-bias" conditions under either visible or UV-vis irradiation. In both operating conditions, the produced electrodes invariably followed the p-n-based photoanode operations but exhibited lower photoelectrochemical performance as compared to the bare n-TiO 2 photoanode under UV-vis light. The reported experimental analysis evidenced that such decreased photoactivity is mainly induced by the scarce efficiency of the nanosized p-n interfaces upon irradiation. To overcome such limitation, a restructuring of the originally electrodeposited p-Cu 2 O was promoted, following a photoelectrochemical post-treatment strategy. p-Cu 2 O, restructured in a 2D leaf-like morphology, allowed reaching an improved photoelectrochemical performance for the p-n-based photoanode under UV-vis light. As compared to the bare n-TiO 2 behavior, such improvement consisted of photoanodic currents up to three times larger. An analysis of the mechanisms driving the transition from compact (∼100 nm) octahedral p-Cu 2 O to wider (∼1 μm) 2D leaf-like structures was performed, which highlighted the pivotal role played by the irradiated n-TiO 2 NTs.