School of Chemistry and Environmental Engineering, Wuhan Institution of Technology, Wuhan 430205, China; Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
School of Chemistry and Environmental Engineering, Wuhan Institution of Technology, Wuhan 430205, China.
J Colloid Interface Sci. 2018 Mar 15;514:576-583. doi: 10.1016/j.jcis.2017.12.066. Epub 2017 Dec 27.
New photocatalytic materials for stable reduction and/or oxidization of water by harvesting a wider range of visible light are indispensable to achieve high practical efficiency in artificial photosynthesis. In this work, we prepared 2D WO·HO and WO nanosheets by a one-pot hydrothermal method and sequent calcination, focusing on the effects of crystal transformation on band structure and photocatalytic performance for photocatalytic water oxidation in the presence of electron acceptors (Ag) under simulated solar light irradiation. The as-prepared WO nanosheets exhibit enhanced rate of photocatalytic water oxidation, which is 6.3 and 3.6 times higher than that of WO·HO nanosheets and commercial WO, respectively. It is demonstrated that the releasing of water molecules in the crystal phase of tungstic acid results in transformation of the crystal phase from orthorhombic WO·HO to monoclinic WO, significantly improving the activity of photocatalytic water oxidation in the presence of Ag because the shift-up of conduction band of WO matches well with the electrode potential of Ag/Ag(s), leading to efficient separation of photoinduced electrons and holes in pure WO nanosheets.
在人工光合作用中，为了实现高效率，需要新的光催化材料来稳定地还原和/或氧化水，并能利用更广泛的可见光。在这项工作中，我们通过一步水热法和随后的煅烧制备了 2D WO·HO 和 WO 纳米片，重点研究了晶体转变对带结构和在模拟太阳光照射下存在电子受体（Ag）时光催化水氧化性能的影响。所制备的 WO 纳米片表现出增强的光催化水氧化速率，分别比 WO·HO 纳米片和商业 WO 高 6.3 和 3.6 倍。结果表明，在水合氧化钨晶体相中释放水分子导致晶体相从正交 WO·HO 转变为单斜 WO，这显著提高了在 Ag 存在下光催化水氧化的活性，因为 WO 的导带位移与 Ag/Ag(s)的电极电势相匹配，从而导致在纯 WO 纳米片中光诱导电子和空穴的有效分离。
