Nitrogen photofixation to produce ammonia has mainly focused on the single photocatalyst leading to poor charge separation and limited reductive capability. In this work, we demonstrate an efficient all solid-state z-scheme heterojunction by immobilization of Fe doped MoS₂ nanobundles on carbon coated porous TiO₂ nanosheets, achieving a high yield of ammonia of 205.7 μg g_cat⁻¹ h⁻¹ in ultrapure water without any sacrificial reagent under illumination. The z-scheme heterojunction has been compared with the designed p-n junction. It is found that the high performance is ascribed to at least three aspects. Firstly, the Fe doped MoS₂ nanobundles provide multiple sites to surface nitrogen reduction reaction. Secondly, the z-scheme system has directed the flow of photocarriers, and hence electrons in high energy level of MoS₂ can be utilized for the surface reduction reaction. Lastly, the charge transfer is significantly improved by the suppressed recombination of photogenerated electrons and holes in the z-scheme junction. The present study has provided a useful strategy to design active composite photocatalysts for nitrogen photofixation.

氮光固定产生氨主要集中在单一光催化剂上，导致电荷分离差和还原能力有限。在这项工作中，我们通过将 Fe 掺杂的 MoS ₂纳米束固定在碳包覆的多孔 TiO ₂纳米片上，证明了一种高效的全固态 z 型异质结，在超纯中实现了 205.7 μg g _cat ^-1 h ^-1的高氨产率光照下不加任何牺牲试剂的水。z 方案异质结已与设计的 pn 结进行了比较。研究发现，高性能至少归功于三个方面。首先，Fe掺杂的MoS ₂纳米束为表面氮还原反应提供了多个位点。其次，z-scheme系统引导了光载流子的流动，因此可以利用MoS ₂高能级的电子进行表面还原反应。最后，通过抑制 z 型结中光生电子和空穴的复合，显着改善了电荷转移。本研究为设计用于固氮的活性复合光催化剂提供了一种有用的策略。