Constructing S-scheme heterojunctions with a robust internal electric field (IEF) to enhance the photocatalytic degradation of chlorinated volatile organic compounds (Cl-VOCs) presents a significant challenge. Herein, an innovative S-scheme heterojunction of N-doped titanium dioxide (TiO₂) and tungsten trioxide (WO₃) with abundant oxygen vacancies (OVs) was first synthesized and manipulated via an eco-friendly two-step plasma. The charge transfer pathway between TiO₂ and WO₃ was analyzed using UV–Vis DRS, XPS, UPS, and EPR measurements, confirming the successful formation of the S-scheme heterojunction. Interestingly, two novel types of IEF: stream-type and waterfall-type were first proposed to distinguish the IEF strength before and after regulation. Under visible light, 5NTW with the optimal ratio (4.66 at% nitrogen and 5 wt% WO₃) achieved the highest degradation efficiency and carbon dioxide mineralization rate of 95.4% and 94.1% for chlorobenzene, respectively. The performance enhancement was attributed to the fact that N-doping modifies the electronic structure and work function of TiO₂, enhancing the Fermi level difference (ΔE_f) with WO₃. Meanwhile, the plasma treatment roughened the surface topography of the catalyst and increased the content of OVs, which serve as charge traps and bolster active sites. These synergies led to a transformation from a stream-type IEF of TW to a waterfall-type IEF of 5NTW. KPFM, zeta potential tests, and DFT calculations confirmed that the IEF strength and the number of electron transfers in the waterfall-type IEF are 3.17 and 2.04 times greater, respectively, than those in the stream-type IEF. This strategy transcends the limitations of previous work, offering a novel perspective on the integrated optimization of photocatalysts for superior performance and also further broadens the application prospects of nonthermal plasma technology.

中文翻译：

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在 N-TiO2/WO3 S 型异质结中等离子体辅助构建瀑布式 IEF，用于高效可见光驱动降解 Cl-VOCs


构建具有稳健内电场 （IEF） 的 S 型异质结以增强氯化挥发性有机化合物 （Cl-VOC） 的光催化降解是一项重大挑战。在此，首次合成了一种具有丰富氧空位 （OVs） 的 N 掺杂二氧化钛 （TiO₂） 和三氧化钨 （WO₃） 的创新 S 型异质结，并通过环保的两步等离子体进行操纵。使用紫外-可见光 DRS、XPS、UPS 和 EPR 测量分析 TiO₂ 和 WO₃ 之间的电荷转移途径，证实了 S 型异质结的成功形成。有趣的是，首次提出了两种新型 IEF：溪流型和瀑布型，以区分调节前后的 IEF 强度。在可见光下，最佳配比 （4.66 at% 氮和 5 wt% WO₃） 的 5NTW 对氯苯的降解效率和二氧化碳矿化率分别为 95.4% 和 94.1%。性能的提高归因于这样一个事实：N 掺杂改变了 TiO₂ 的电子结构和功函数，增强了与 WO₃ 的费米能级差 （ΔE_f）。同时，等离子体处理使催化剂的表面形貌粗糙化，并增加了 OVs 的含量，OVs 用作电荷陷阱和增强活性位点。这些协同效应导致从 TW 的溪流型 IEF 转变为 5NTW 的瀑布式 IEF。KPFM、zeta 电位测试和 DFT 计算证实，瀑布型 IEF 中的 IEF 强度和电子转移次数分别是流型 IEF 中的 3.17 倍和 2.04 倍。 这一策略超越了以往工作的局限性，为光催化剂的集成优化以获得卓越的性能提供了新的视角，也进一步拓宽了非热等离子体技术的应用前景。