A hydrogen-doped helium atmospheric pressure plasma jet (APPJ) is shown to be effective for the chemical reduction of metal oxides. Copper and tin oxide films (CuO and SnO₂) show rapid (<2 seconds) and complete reduction to zero valence metal after exposure to the plasma jet, as revealed by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, and Raman spectroscopy. After a total residence time of the plasma jet of 100 seconds, titanium oxide (TiO₂) produced a surface decorated with Ti²⁺, Ti³⁺ and Ti⁴⁺ with proportions of 16, 38 and 46 atom%, respectively, as determined by XPS peak integration. Similarly, with tungsten oxide (WO₃), after exposure for a few seconds, W⁵⁺ was produced, yielding a deep blue electrically conductive coating. The treatment of these oxide films by this dielectric radio frequency (RF) barrier discharge plasma jet provides a level of redox conversion not seen in any other technique, particularly for TiO₂, especially with a comparable power input. The precise nature of the reduction is unclear; however, the involvement of free electrons may have an important role in the reduction process.

中文翻译：

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使用H2 / He大气压等离子流对金属氧化物薄膜进行构图

氢掺杂的氦气大气压等离子体射流（APPJ）被证明对金属氧化物的化学还原有效。X射线光电子能谱（XPS），俄歇电子能谱和拉曼光谱表明，铜和氧化锡膜（CuO和SnO ₂）在暴露于等离子流后显示出快速的（<2秒）并完全还原为零价金属。光谱学。在等离子流的总停留时间为100秒之后，氧化钛（TiO ₂）产生了用Ti 2 ⁺，Ti ³⁺和Ti ⁴⁺装饰的表面，分别确定为16、38和46原子％。通过XPS高峰整合。类似地，使用氧化钨（WO ₃），在曝光几秒钟后，W产生⁵⁺，产生深蓝色导电涂层。通过该介电射频（RF）势垒放电等离子体射流对这些氧化膜的处理提供了在任何其他技术中都看不到的氧化还原转换水平，尤其是对于TiO _2而言，尤其是在可比较的功率输入下。减少的确切性质尚不清楚；然而，自由电子的参与可能在还原过程中起重要作用。