Bismuth vanadate (BiVO₄) has surface states that give rise to defect levels that mediate electron-hole recombination. In order to minimize the inefficiencies, an ultrathin Al overlayer was deposited on the BiVO₄ electrodes. A 54 % improvement on the photocurrent density was obtained using the Al-modified BiVO₄ electrode, accompanied by a 15 % increase in stability over 7.5 h of continuous irradiation. Moreover, surface capacitance measurements showed that the Al overlayer was indeed passivating the surface states. We also shed light on the deposition of an Al overlayer on the surface of BiVO₄, by investigating the process on model BiVO₄ powders. This study presents useful, previously unreported information about the surface chemistry of BiVO₄ based on experimental methods and gives unique insights on the characterization of the BiVO₄ surface. The existence of surface reactive sites on BiVO₄ was confirmed and quantified (1.5 reactive sites/nm²) via chemical titration.

钒酸铋（BiVO ₄）的表面状态会导致缺陷水平介导电子-空穴复合。为了最大程度地降低效率，在BiVO ₄电极上沉积了一层超薄的Al覆盖层。使用Al改性的BiVO ₄电极可将光电流密度提高54％，并在7.5 h的连续辐照下使稳定性提高15％。此外，表面电容测量表明，Al覆盖层确实钝化了表面状态。通过研究BiVO ₄模型上的过程，我们还揭示了Al覆盖层在BiVO ₄表面上的沉积。粉末。这项研究基于实验方法，提供了有关BiVO ₄表面化学的有用的，以前未曾报道的信息，并对BiVO ₄表面的表征提供了独特的见解。通过化学滴定确认并定量了BiVO ₄上表面反应位点的存在（1.5个反应位点/ nm ²）。