Here, we report thorough spectroscopic characterization of tungsten oxide (WO₃) nanoparticles (NPs) and WO₃ NPs surface doped with transition metal (TM) ions (TM@WO₃; TM = Cr³⁺, Mn²⁺, Fe³⁺, Co²⁺, and Ni²⁺) by using various surface analysis techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), high-resolution X-ray photoelectron spectroscopy (HRXPS), and extended X-ray absorption fine structure (EXAFS). At first glance, the morphologically distinct features were not perceivable across TM dopants. However, the detailed XPS analysis confirmed that the WO₃ NPs doped with Cr and Fe ions formed a relatively large number of surface defects. Moreover, we found through EXAFS analysis that the chromium and iron ions doping on WO₃ NPs promoted the dramatic shortening of the WO bond length as compared to pristine WO₃ and other metal ion doped WO₃ NPs. Much enhanced photocatalytic and electrocatalytic activities of Cr@WO₃ and Fe@WO₃, which relied on the different density of surface defects created by the charge and size of the TM dopants, were demonstrated in the photocatalytic degradation reactions of 4-chlorophenol and the electrocatalytic hydrogen evolution reaction. The present result can serve as a practical guideline for atomically precise control of oxygen vacancy toward the development of high-performance metal oxide photocatalysts.

在这里，我们报告了氧化钨 (WO ₃ ) 纳米粒子 (NPs) 和掺杂过渡金属 (TM) 离子 (TM@WO ₃ ; TM = Cr ³⁺ , Mn ²⁺ , Fe ³⁺ ) 的 WO ₃ NPs 表面的全面光谱表征、Co ²⁺和 Ni ²⁺ ) 通过使用各种表面分析技术，例如透射电子显微镜 (TEM)、X 射线衍射 (XRD)、X 射线吸收光谱 (XAS)、高分辨率 X 射线光电子能谱(HRXPS) 和扩展 X 射线吸收精细结构 (EXAFS)。乍一看，跨 TM 掺杂剂无法感知形态上不同的特征。然而，详细的 XPS 分析证实，WO ₃掺杂了 Cr 和 Fe 离子的 NPs 形成了相对大量的表面缺陷。此外，我们通过 EXAFS 分析发现，与原始 WO ₃和其他金属离子掺杂的 WO ₃ NPs相比，在 WO ₃ NPs上掺杂的铬和铁离子促进了WO键长的显着缩短。Cr@WO ₃和Fe@WO _{3 的}光催化和电催化活性大大增强依赖于由 TM 掺杂剂的电荷和尺寸产生的不同密度的表面缺陷，在 4-氯苯酚的光催化降解反应和电催化析氢反应中得到了证明。目前的结果可以作为原子级精确控制氧空位以开发高性能金属氧化物光催化剂的实用指南。