Park Eunoak, Patil Santosh S, Lee Hyeonkwon, Kumbhar Vijay S, Lee Kiyoung
Department of Chemistry and Chemical Engineering, Inha University, 22212 Incheon, Republic of Korea.
Research Institute of Environmental Science & Technology, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, Republic of Korea.
Nanoscale. 2021 Oct 21;13(40):16932-16941. doi: 10.1039/d1nr04763a.
Tungsten oxide/bismuth vanadate (WO/BiVO) has emerged as a promising photoanode material for photoelectrochemical (PEC) water splitting owing to its facilitated charge separation state differing significantly from single phase materials. Practical implementation of WO/BiVO is often limited by poor stability arising from the leaching of V from BiVO during PEC operations. Herein, we demonstrate that the synthesis of a tungsten oxide/bismuth vanadate/titanium oxide (WO/BiVO/TiO) heterostructure onto a fluorine-doped tin oxide-coated glass substrate through a combined simple hydrothermal-spin coating strategy will advance PEC performance while slowing water oxidation kinetics and improving photostability. We show that surface postmodification with a nanometer-thick layer of (1 0 1) monofacet-selective single-crystalline TiO provides stable photocurrent density, up to 1.04 mA cm at 1.23 V (compared to a reversible hydrogen electrode in 0.5 M NaSO), with excellent quantum efficiency (45% at 460 nm) and long-term photostability (24 h). Interestingly, crystalline TiO activation layers behave differently from previous TiO amorphous layers, blocking surface defects while improving corrosion resistance, photostability, and the electron transfer process. These results indicate a ≈2.5 times enhancement in photoelectrocatalytic activity related to referenced WO/BiVO photoanodes, encouraging the use of single-crystalline TiO modulations to develop a range of materials for PEC/photocatalytic applications.
氧化钨/钒酸铋（WO/BiVO）因其电荷分离状态比单相材料有显著改善，已成为一种有前景的用于光电化学（PEC）水分解的光阳极材料。WO/BiVO的实际应用常常受到PEC操作过程中钒酸铋中钒浸出导致稳定性差的限制。在此，我们证明通过简单水热-旋涂相结合的策略，在氟掺杂氧化锡涂层玻璃基板上合成氧化钨/钒酸铋/二氧化钛（WO/BiVO/TiO）异质结构，将提高PEC性能，同时减缓水氧化动力学并提高光稳定性。我们表明，用纳米厚的（1 0 1）单平面选择性单晶TiO进行表面后修饰可提供稳定的光电流密度，在1.23 V时高达1.04 mA/cm²（相对于0.5 M Na₂SO₄中的可逆氢电极），具有优异的量子效率（460 nm时为45%）和长期光稳定性（24小时）。有趣的是，结晶TiO活化层的行为与之前的TiO非晶层不同，它能阻挡表面缺陷，同时提高耐腐蚀性、光稳定性和电子转移过程。这些结果表明，与参考的WO/BiVO光阳极相比，光电催化活性提高了约2.5倍，这鼓励使用单晶TiO调制来开发一系列用于PEC/光催化应用的材料。
