Degradation of organic pollutants using photocatalysts has gained utmost importance, due to the increasing environmental pollution. Despite various attempts to improve the photocatalytic efficiency of well-known photocatalysts such as titanium dioxide (TiO₂), by making them visible light active, various issues need to be resolved. In this work, attempts have been made to improve the visible light absorption capacities of the electrospun TiO₂ nanofibers by modification using squaric acid (SqA). An interfacial charge transfer complex is formed by the condensation reaction between the hydroxyl groups on the surface of the TiO₂ nanofibers and the SqA ligand. Various characterizations confirmed that the modification using SqA had led to the formation of the interfacial charge transfer layer, without affecting the crystallinity or morphology of the TiO₂ nanofibers. The modified TiO₂ nanofibers showed sensitivity to visible light with red shift in the optical absorption. It exhibited an improved photocatalytic efficiency of 85% against the degradation of tetracycline, compared with 60% for unmodified TiO₂ nanofibers. It also showed an increased rate of degradation of 0.21 mg/L/min, when compared with the 0.13 mg/L/min of unmodified TiO₂ nanofibers.

中文翻译：

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使用方酸制备可见光敏感电纺 TiO2 纳米纤维用于光催化应用

由于环境污染日益严重，使用光催化剂降解有机污染物变得至关重要。_{尽管人们尝试通过使二氧化钛（TiO 2} ）等众所周知的光催化剂具有可见光活性来提高其光催化效率，但仍有许多问题需要解决。在这项工作中，人们尝试通过使用方酸（SqA）进行改性来提高电纺TiO _{2纳米纤维的可见光吸收能力。TiO 2}表面羟基之间发生缩合反应形成界面电荷转移络合物纳米纤维和 SqA 配体。各种表征证实，使用SqA的改性导致了界面电荷转移层的形成，而不影响TiO ₂纳米纤维的结晶度或形态。改性TiO ₂纳米纤维表现出对可见光的敏感性，并且光学吸收发生红移。_{它对四环素的降解表现出 85% 的光催化效率，而未改性的 TiO 2}纳米纤维的光催化效率为 60% 。_{与未改性的 TiO 2}纳米纤维的 0.13 mg/L/min 相比，它还显示出 0.21 mg/L/min 的降解速率增加。