±¤Àü±âÈ­Çм¿À» È°¿ëÇÑ °íºÎ°¡°¡Ä¡ ¹°Áú »ý»ê
¹ÚÁ¾Çõ
¿¬¼¼´ë

we reported that a SnO2 overlayer with oxygen vacancies (SnO2-x) can tune the activity and selectivity for PEC water oxidative H2O2 generation using a BiVO4 photoanode under simulated solar light. Our investigations on the charge exchange mechanism demonstrated the near-suppression of O2 evolution during PEC water splitting, due to the photogenerated holes of BiVO4 migrating to the SnO2-x overlayer; this process regulated the competitive 2-electron/4-electron transfer to a 2-electron/1-electron transfer by interface energetics and the concomitant suppression of H2O2 decomposition. As a result, the FE for H2O2 generation reached ca. 86% over a wide potential range from 0.6 to 2.1 V vs. RHE with an average H2O2 evolution rate of 0.825 ¥ìmol/min/cm-2 at 1.23 V vs. RHE. Because the thermodynamically less favourable H2O oxidative H2O2 reaction, this study highlighted the significance of a surface state modulation on the photoanode/electrolyte interface, opening the possibility of highly selective H2O2 synthesis from PEC water splitting by Fermi level pining effect.