Near-Complete Suppression of Surface Recombination in Solar Photoelectrolysis by “Co-Pi” Catalyst-Modified W:BiVO 4

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…

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  National Science Foundation