Different numbers of N/Ti³⁺ codoped triphasic TiO₂ layer are deposited on TiO₂ nanotube arrays by hydrothermal reaction of TiN and TiO₂ nanotube arrays. The crystal structure, morphology, and composition of the as-prepared samples and their photoelectrochemical properties are investigated and discussed. There are obviously red shift of the optical edge and enhanced visible light absorption for the resulting samples in the ultraviolet–visible diffuse reflectance spectroscopy. Besides, the photoelectrochemical tests indicate that the N/Ti³⁺ codoped triphasic TiO₂-TiO₂ nanotube array samples exhibit an enhanced photocurrent density and photovoltage under visible light irradiation. The maximum photoconversion efficiency of N/Ti³⁺ codoped triphasic TiO₂-TiO₂ nanotube array sample is 2.1 times higher than that of pristine TiO₂ nanotube arrays. In addition, reduced impedance, higher carrier density, and excellent stability of photoelectrochemical performance of N/Ti³⁺ codoped triphasic TiO₂-TiO₂ nanotube array samples are also demonstrated. Finally, a plausible mechanism for the charge migration and separation on N/Ti³⁺ codoped triphasic TiO₂-TiO₂ nanotube array samples is proposed. This study provides a novel strategy to design and fabricate visible-light-driven TiO₂ based composites and promote their applications in the field of solar energy utilization.

通过TiN和TiO ₂纳米管阵列的水热反应，将不同数量的N / Ti ³⁺共掺杂三相TiO ₂层沉积在TiO ₂纳米管阵列上。研究和讨论了所制备样品的晶体结构，形态，组成及其光电化学性能。在紫外-可见漫反射光谱法中，所得样品的光学边缘明显发生红移，可见光吸收增强。此外，光电化学测试表明N / Ti ³⁺共掺杂三相TiO ₂ -TiO ₂纳米管阵列样品在可见光照射下表现出增强的光电流密度和光电压。N / Ti ³⁺共掺杂的三相TiO ₂ -TiO ₂纳米管阵列样品的最大光转换效率是原始TiO ₂纳米管阵列的2.1倍。另外，还证明了N / Ti ³⁺共掺杂的三相TiO ₂ -TiO ₂纳米管阵列样品的降低的阻抗，更高的载流子密度和优异的光电化学性能稳定性。最后，在N / Ti ³⁺共掺杂的三相TiO ₂ -TiO ₂上电荷迁移和分离的合理机理提出了纳米管阵列样品。这项研究提供了一种新颖的策略来设计和制造可见光驱动的TiO ₂基复合材料，并促进其在太阳能利用领域的应用。