The photocatalytic conversion of molecular O into reactive oxygen species, such as superoxide radicals (·O), has become the focus in the oxidative removal of organic pollutants. Nevertheless, the inefficient light absorption, limited adsorption of O, and the fast recombination rate of photo-induced electron-hole pairs considerably impede the conversion efficiency of the photocatalysts. Herein, we report the synthesis of Ag@LAFO photocatalyst, which contains Ag nanoparticles (NPs)-decorated LAFO (Ag-substituted LaFeO), to enhance the photodegradation efficiency of tetracycline (TC) with the assistance of water oxidation. Structural and spectroscopic analyses confirmed the successful decoration of Ag NPs on LAFO, which was prepared by substituting 10 % La with Ag. The efficiency of TC photocatalytic degradation rate of Ag@LAFO is 76.25 %, which is 6.1-fold higher than that of pure LFO (12.41 %). The trapping experiment of active radicals verified that ·O was crucial in the decomposition of TC molecules and was continuously supplied by the reduction of O molecules supported by photocatalytic water oxidation. Moreover, the Ag NPs in Ag@LAFO were found to be crucial for boosting the capture of photo-induced electrons and the activation of adsorbed O. This study offers a new perspective on the conversion of O to ·O with the assistance of photocatalytic water oxidation for photocatalytic degradation of organic pollutants.

中文翻译：

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制备Ag修饰的La0.9Ag0.1FeO3，在可见光下水氧化辅助下高效光催化降解四环素

光催化将O分子转化为超氧自由基（·O）等活性氧已成为有机污染物氧化去除的研究热点。然而，低效的光吸收、有限的 O 吸附以及光诱导电子空穴对的快速复合率极大地阻碍了光催化剂的转换效率。在此，我们报道了Ag@LAFO光催化剂的合成，其中含有Ag纳米粒子（NPs）装饰的LAFO（Ag取代的LaFeO），可在水氧化的辅助下提高四环素（TC）的光降解效率。结构和光谱分析证实了 Ag NPs 在 LAFO 上的成功修饰，LAFO 是通过用 Ag 取代 10% La 制备的。 Ag@LAFO的TC光催化降解效率为76.25%，是纯LFO（12.41%）的6.1倍。活性自由基捕获实验证实，·O对于TC分子的分解至关重要，并通过光催化水氧化支持的O分子还原持续供应。此外，Ag@LAFO 中的 Ag NP 对促进光生电子的捕获和吸附 O 的活化至关重要。这项研究为光催化水辅助下 O 转化为·O 提供了新的视角光催化氧化降解有机污染物。