| 초록 |
Here, we report pH-independent high-efficiency photoelectrochemical (PEC) water oxidation via facile electrochemical hydroxylation of the surface of rutile TiO2 (rTiO2). The electrochemically treated rTiO2 (ECT-rTiO2) shows a photocurrent density of 1.3 mA cm-2 over the entire pH range (pH 0 ~ pH 14) without the incorporation of any co-catalysts, hole scavengers or over-layers. Moreover, a charge transfer efficiency of ~100% is achieved for ECT-rTiO2 at 1.23 V vs RHE, which implies that the electrochemical-reduction-induced surface -OH successfully promotes the water oxidation reaction pathway. According to our density functional theory (DFT) calculations, the ECT- rTiO2 surface can possess increased -OH coverage, faster decay of the positive surface charge in acidic environments, and weakened H+ adsorption for pH＞7, which enable enhanced water oxidation performance independent of the pH value of the electrolyte. |
