Homogeneous nitrogen-doped oxides are of wide visible light utilization for promising photocatalytic water splitting to produce hydrogen, but currently the poor charge separation severely limits their photocatalytic performances. In this work, a homogeneous nitrogen-doped tunneled oxide of MgTa₂O_6−xN_x with an absorption edge of 570 nm was selected as a prototype to investigate the influence of ZrO₂ modification on the charge separation as well as photocatalytic performance. It is interesting to observe that the formation of the reduced tantalum species, regarded as recombination centers, in the MgTa₂O_6−xN_x sample could be effectively inhibited via the surface passivation with ZrO₂ nanoparticles, based on which the photocatalytic water reduction and oxidation half-reaction activities could be remarkably promoted. Together with modification of the deposited Pt cocatalyst, the optimized H₂ evolution rate over Pt-ZrO₂/MgTa₂O_6−xN_x (Zr/Ta = 0.10) photocatalyst was almost 4.5 times as high as that of the pristine Pt-MgTa₂O_6−xN_x sample free of ZrO₂ modification, whose apparent quantum yield at 420 nm (± 15 nm) achieved herein was superior to those of other reported homogeneous nitrogen-doped photocatalysts. The improved charge separation probably attributes to the introduction of Zr–O–Ta bond after ZrO₂ modification, which is helpful to stabilize the tantalum species at more cationic state and inhibit the formation of the reduced tantalum species. This work extends the application territory of ZrO₂ modification to the homogeneous nitrogen-doped oxide photocatalysts, and demonstrates its feasibility and effectiveness for remarkably enhanced photocatalytic water splitting performance.

均质氮掺杂氧化物具有广泛的可见光利用率，有望用于光催化水分解制氢，但目前较差的电荷分离严重限制了其光催化性能。在这项工作中，选择吸收边为570 nm的均质氮掺杂隧道氧化物MgTa ₂ O _{6− x} N _{x作为原型，研究ZrO 2}改性对电荷分离和光催化性能的影响。有趣的是，通过ZrO ₂纳米颗粒的表面钝化，可以有效抑制MgTa ₂ O _{6− x} N _x样品中被视为复合中心的还原钽物种的形成，在此基础上光催化水还原并能显着促进氧化半反应活性。结合沉积 Pt 助催化剂的改性， Pt-ZrO ₂ /MgTa ₂ O _{6− x} N _{x (Zr/Ta = 0.10) 光催化剂的优化 H 2}析出速率几乎是原始 Pt- 的 4.5 倍。不含ZrO ₂改性的MgTa ₂ O _{6− x} N _x样品，其在420 nm（±15 nm）处的表观量子产率优于其他报道的均质氮掺杂光催化剂。_{电荷分离的改善可能归因于ZrO 2}改性后Zr-O-Ta键的引入，这有助于将钽物质稳定在更多的阳离子状态并抑制还原钽物质的形成。_{这项工作将ZrO 2}改性的应用领域扩展到均相氮掺杂氧化物光催化剂，并证明了其显着增强光催化水分解性能的可行性和有效性。