N/Si共掺杂的TiO_2 NRs光电化学性质研究的新视点

New Sight into the Photo-electrochemical Properties of N/Si Co-doped TiO_2 NRs

元素掺杂是抑制电荷重组和改变TiO_2带隙的有效手段,因此提高了其光催化活性。在这里,我们首先报告了N/Si共掺杂单晶金红石TiO_2纳米线通过一步水热法诱导的共掺杂制备的,用于改善在FTO电基底上生长的TiO_2纳米线的光电化学性能。这项工作报告了,用传统的电化学法研究在1.23 V时表现出2.17 m A cm-2的光电流,优异的光电化学性能可归因于N和Si共掺杂剂改变TiO_2带隙,增强对紫外和可见光区中的入射光子吸收的,并提高了光电转换效率。然后结合原位、实时的UV-vis/SECM技术研究了改善的光电阳极/电解液界面间的光诱导电子转移(PET)行为。发现N/Si共掺杂TiO_2纳米线的keff最大,说明N/Si共掺杂的协同作用共同抑制电荷重组,提高了量子效率,引起微区PET动力学增加。

Elemental doping is an effective means of suppressing charge recombination and changing the band gap of TiO2, thus improving its photocatalytic activity. Here, we first report the co-doping method of N/Si co-doped single-crystal rutile TiO2 nanowires by one-step hydrothermal method to improve the photo-electrochemical performance of TiO2 nanowires grown on FTO substrate. This work reported that photocurrents of 2.17 mA·cm-2 at 1.23 V were studied using conventional electrochemical method. Excellent photo-electrochemical performance could be attributed to the fact that N and Si co-dopants changed the TiO2 bandgap, enhancing absorbs incident photons in the ultraviolet and visible regions, improving the photoelectric conversion efficiency. The improved photo-anode/electrolyte interface was then investigated by UV-vis/SECM techniques with in-situ, real-time for light-induced electron transfer （PET） behavior. N/Si co-doped TiO2 nanowires given the largest keff; indicating that the N/Si co-doping inhibited the charge recombination, increased the quantum efficiency, and caused the increase in the kinetics of PET in the micro-domain.