Non-metal codoping including nitrogen (N) and hydrogen (H) codoping has been emerging as an effective way to improve the performance of anatase TiO₂ in solar cell, fuel conversion and pollutant degradation. However, the mechanism of the synergistic effect of N doping and H doping on TiO₂ is still far from thorough. In this paper, N and H codoped TiO₂ nanoparticles are obtained by N doping in ammonia and then H doping in hydrogen gas, which achieves substantially boosted efficiency and reaction rate in the photocatalytic degradation of benzene under visible light excitation. The superiority of the N–H–TiO₂ photocatalyst was fully elaborated by comparing with H–N–TiO₂, which was obtained by thermal treating in H₂ and then NH₃. The reaction rate of N–H–TiO₂ in the photocatalytic degradation of benzene was nearly 2 times that of H–N–TiO₂, ∼7 times higher than that of pristine TiO₂. Furthermore, the cycling test revealed the high repeatability and stability of the N–H–TiO₂ photocatalyst. The excellent performance N–H–TiO₂ was attributed to an adequate concentration of N_iH_i defects occupying interstitial sites of the TiO₂ structure and a disordered surface layer introduced by annealing in NH₃ and H₂ successively. The synergistic effect of N–H-codoping also increased the separation and migration of electron–hole pairs triggering a photoinduced redox reaction on the surface of TiO₂.

中文翻译：

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TiO2光催化剂的N-H-和H-N-共掺杂在可见光下有效降解苯的机理研究

包括氮（N）和氢（H）共掺杂在内的非金属共掺杂已成为提高锐钛矿TiO ₂在太阳能电池、燃料转化和污染物降解中的性能的有效途径。然而，N掺杂和H掺杂对TiO ₂的协同作用机理还远未完全。在本文中，N和H共掺杂的TiO ₂纳米颗粒是通过在氨中掺杂N，然后在氢气中掺杂H，在可见光激发下显着提高苯的光催化降解效率和反应速率。_{通过与H-N-TiO 2}的比较，充分阐述了N-H-TiO ₂光催化剂的优越性_{, 它是通过在 H 2}和 NH ₃中热处理获得的。_{N-H-TiO 2}在光催化降解苯中的反应速率是H-N-TiO ₂的近 2 倍，是原始 TiO ₂的 7 倍。此外，循环测试揭示了 N-H-TiO ₂光催化剂的高重复性和稳定性。_{N-H-TiO 2}的优异性能归因于足够浓度的 N _i H _i缺陷占据 TiO _{2结构的间隙位点以及通过在 NH 3}和 H ₂中退火引入的无序表面层依次。N-H-共掺杂的协同效应也增加了电子-空穴对的分离和迁移，从而引发了TiO ₂表面的光致氧化还原反应。