With a coordination complex modified polyoxometalate compound and filter paper as precursors, an oxygen vacancy rich composite photocatalyst (WO_3−x/NC) composed of nonstoichiometric tungsten oxide (WO_3−x, 1 > x > 0) and a 3D nitrogen doped carbon matrix was synthesized successfully. In WO_3−x/NC, WO_3−x nanoparticles with a size of about 3 to 6 nm are dispersed homogenously in a 3D nitrogen doped carbon matrix. The existence of oxygen vacancies has been confirmed by electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS). WO_3−x/NC exhibits remarkable photocatalytic activity for the degradation of volatile organic compounds (VOCs). Under visible light irradiation it can completely degrade formaldehyde and benzene in 90 min. The durability of WO_3−x/NC is also excellent. After 8 successive reaction cycles the removal rate stays as high as 92%. More importantly, WO_3−x/NC also exhibits outstanding visible and near-infrared light driven photocatalytic H₂ evolution activity. The prominent VOC removal and H₂ production properties can be attributed to the oxygen vacancies from WO_3−x and the good conductivity of the nitrogen doped carbon matrix. We hope WO_3−x/NC can be applied as an effective material in air purification and H₂ energy development.

中文翻译：

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存在于3D氮掺杂碳基质中的非化学计量氧化钨，一种用于氧空位的VOC降解和H ₂产生的复合光催化剂†

以配位配合物改性的多金属氧酸盐化合物和滤纸为前体，由非化学计量的氧化钨（WO _{3− x}，1> x > 0）和3D氮掺杂的碳组成的富氧空位复合光催化剂（WO _{3 x} / NC）基质合成成功。在WO _{3- x} / NC中，大小为约3至6 nm的WO _{3- x}纳米颗粒均匀地分散在3D氮掺杂碳基质中。通过电子自旋共振（ESR）和X射线光电子能谱（XPS）确认了氧空位的存在。WO _{3− x}/ NC对挥发性有机化合物（VOC）的降解表现出显着的光催化活性。在可见光照射下，它可以在90分钟内完全降解甲醛和苯。WO _{3- x} / NC的耐久性也极好。经过8个连续的反应循环后，去除率保持高达92％。更重要的是，WO _{3- x} / NC还表现出出色的可见光和近红外光驱动的光催化H ₂析出活性。突出的VOC去除和H ₂产生特性可归因于WO _{3- x}的氧空位和氮掺杂碳基质的良好电导率。我们希望WO _{3− x}/ NC可用作空气净化和H ₂能量开发的有效材料。