Improvement of Solar Energy Conversion with Nb‐Incorporated TiO2 Hierarchical Microspheres. Issue 10 (19th March 2013)

• Record Type: Journal Article
• Authors: Hoang, Son; Ngo, Thong Q.; Berglund, Sean P.; Fullon, Raymond R.; Ekerdt, John G.; Mullins, C. Buddie
• Is Part Of: Chemphyschem. Volume 14:Issue 10(2013)
• Page Start: 2270
• Page End: 2276
• Publication Date: 2013-03-19
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201201092
• Languages: English
• ISSNs: 1439-4235

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Niobium‐modified TiO₂ hierarchical spherical micrometer‐size particles, which consist of many nanowires, are synthesized by solvothermal synthesis and studied as photoelectrodes for water photo‐oxidation and dye‐sensitized solar cell (DSSC) applications. Incorporation of Nb leads to a rutile‐to‐anatase TiO₂ phase transition in the TiO₂ hierarchical spheres (HSs), with the anatase percentage increasing from 0 % for the pristine TiO₂ HSs to 47.6 % for the 1.82 at. % Nb‐incorporated TiO₂ sample. Incorporation of Nb leads to significant improvements in water photo‐oxidation with the photocurrents reaching 70.5 μA cm⁻² at 1.23 V versus the reversible hydrogen electrode, compared with 28.3 μA cm⁻² for the pristine TiO₂ sample. The photoconversion efficiency of Nb:TiO₂ HS‐based DSSCs reaches 6.09±0.15 % at 0.25 at. % Nb, significantly higher than that for the pristine TiO₂ HS cells (3.99±0.02 %). In addition, the incident‐photon‐to‐current efficiency spectra for DSSCs show that employing TiO₂ and Nb:TiO₂ HSs provides better light harvesting, especially of long‐wavelength photons, than anatase TiO₂ nanoparticle‐based DSSCs.</p> </abstract>