title: Near-complete suppression of surface recombination in solar photoelectrolysis by "Co-Pi" catalyst-modified W:BiVO4.
abstract: The influence of an earth-abundant water oxidation electrocatalyst (Co-Pi) on solar water oxidation by W:BiVO(4) has been studied using photoelectrochemical (PEC) techniques. Modification of W:BiVO(4) photoanode surfaces with Co-Pi has yielded a very large (∼440 mV) cathodic shift in the onset potential for sustained PEC water oxidation at pH 8. PEC experiments with H(2)O(2) as a surrogate substrate have revealed that interfacing Co-Pi with these W:BiVO(4) photoanodes almost completely eliminates losses due to surface electron-hole recombination. The results obtained for W:BiVO(4) are compared with those reported recently for Co-Pi/α-Fe(2)O(3) photoanodes. The low absolute onset potential of ∼310 mV vs RHE achieved with the Co-Pi/W:BiVO(4) combination is promising for overall solar water splitting in low-cost tandem PEC cells, and is encouraging for application of this surface modification strategy to other candidate photoanodes.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.
authors.forename: Diane K
authors.initials: DK
authors.lastname: Zhong
authors.forename: Sujung
authors.initials: S
authors.lastname: Choi
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gamelin