WO₃ film with reasonable morphology could be a promising photocatalytic material for indoor air purification. Herein, we constructed WO₃ nanoplate film for photocatalytic degradation of gaseous acetaldehyde. The WO₃ nanoplate film was prepared by nitric acid corrosion of W foil using oxalic acid for morphology regulation. SEM, XRD, and XPS evidenced that the monoclinic phase WO₃ nanoplates grew on W foil. The oxalic acid anchored on the specific faces of the tungsten oxide hydrate facilitated for forming high quality larger and thinner WO₃ nanoplates. UV–vis diffuse reflection spectra (DRS) manifested that the oxalic acid modulated WO₃ nanoplate films possess smaller absorption edge and wider solar light absorption region. The oxalic acid contributed to obtain efficient WO₃ nanoplate film photocatalyst for gaseous acetaldehyde decomposition under simulated solar light irradiation, which was response for the increased crystallinity and more surface reactive sites as well as the enhanced light absorption. The morphology modulation by oxalic acid will pave the way for synthesis of practical WO₃ films in environment purification.

形态合理的WO ₃薄膜可能是一种有前景的光催化材料，可用于室内空气净化。本文中，我们构建了WO ₃纳米板膜用于光催化降解气态乙醛。WO ₃纳米板膜的制备是通过草酸对W箔进行硝酸腐蚀来进行形态调节的。SEM，XRD和XPS证明单斜相WO ₃纳米板在W箔上生长。锚固在氧化钨水合物特定表面上的草酸有助于形成高质量的更大，更薄的WO ₃纳米板。紫外可见漫反射光谱（DRS）表明草酸调节了WO ₃纳米板膜具有较小的吸收边缘和较宽的太阳光吸收区域。草酸有助于获得有效的WO ₃纳米板薄膜光催化剂，用于在模拟太阳光照射下气态乙醛分解，这是对结晶度增加和更多的表面反应位以及增强的光吸收的响应。草酸的形态调节将为在环境净化中合成实用的WO ₃薄膜铺平道路。