title: Got TiO2 nanotubes? Lithium ion intercalation can boost their photoelectrochemical performance.
abstract: Cations such as H(+) and Li(+) are intercalated into TiO(2) nanotube arrays by subjecting them to short-term electrochemical pulses at controlled potentials (<-1.0 V vs Ag/AgCl). The intercalation of these small cations has a profound effect toward enhancing photocurrent generation under UV light irradiation. A nearly three-fold increase in the photoconversion efficiency (IPCE) was observed upon intercalation of Li(+) ions into TiO(2) nanotube arrays. The intercalation process is visualized by the color change from gray to blue. Spectroelectrochemical measurements were carried out to monitor the absorption changes at different applied potentials. The analysis of the V(oc) decay following termination of UV light shows a significant decrease in the rate of recombination of accumulated electrons upon Li(+) ion intercalation.
authors.affiliation: Radiation Laboratory and Departments of Chemistry and Biochemistry, and Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Meekins
authors.forename: Prashant V
authors.initials: PV
authors.lastname: Kamat
mesh_terms: D000042:Absorption; D017097:Electric Impedance; D004563:Electrochemistry; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry*; D055620:Optical Phenomena; D055668:Photochemical Processes; D013057:Spectrum Analysis; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D008094:Lithium; D014025:Titanium