Interface engineering of nanoceramic hematite photoelectrode for solar energy conversion
André L. M. Freitas, Dereck N.F. Muche, E. R. Leite, Flávio L. Souza
Abstract
Abstract This work addresses the role of different modifiers on the overall photocurrent response, which allowed a dual material insertion, increasing the charge separation without compromise the surface catalysis. Sn‐addition onto nanoceramic hematite photoelectrodes clearly increased flat band potential, promoting a good charge separation, and shifting the onset to a higher potential, attributed to the surface‐trapping state created by this modification. Notoriously, Sn‐hematite photoelectrodes loaded with NiFeO x exhibited the highest photocurrent density, suggesting a partially recovered surface‐trapping states created during the electrode designing. The well‐known cocatalyst acted in the overall photoelectrocatalytic response with no significant effect on the turn‐on voltage, in other words, with minor effect related to catalytic efficiency. The dual modification contributes to understand the role of different modifiers allowing to satisfactorily improve charge separation while maintaining the conductivity attributed to IV‐group ions.