Abstract Environmentally friendly, chemically inert, and cost-effective 10 nm-sized MgO/TiO2 nanocomposites were prepared by a chemical precipitation method at room temperature and followed by calcination. The structural and optical properties of photocatalyst were characterized by XRD, SEM, TEM, XPS, EIS, PL, and DRS. The MgO/TiO2 photocatalysts were tested for the degradation of methylene blue (MB) dye using visible light instead of UV irradiation. The highest photodegradation efficiency of 99.7% was achieved by MgO/TiO2-30 with a 30 wt% Mg precursor within 120 min. The effect of calcination temperature on the catalytic activity of the catalyst was also investigated. The degradation of MB was confirmed using HPLC. The rate constant of MgO/TiO2-30 was 2.4 × 10−2 min−1, which is 4 times greater than that of bare P25–TiO2 with a rate constant of 6.0 × 10−3 min−1. The excellent photocatalytic activity of MgO/TiO2 arises because of the incorporation of MgO to the 10 nm-sized TiO2 to form the MgO/TiO2 interface. A concept of the stoichiometric/nonstoichiometric oxide interface for better charge transport is proposed. The recyclability of the photocatalyst was evaluated. Finally, the suggestive reaction mechanism was also proposed.

中文翻译：

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10 nm 可见光 TiO2 光催化剂在 MgO 存在下降解亚甲蓝

摘要 采用化学沉淀法在室温下通过煅烧制备了环境友好、化学惰性、成本效益好的 10 nm 尺寸的 MgO/TiO2 纳米复合材料。通过XRD、SEM、TEM、XPS、EIS、PL和DRS对光催化剂的结构和光学性质进行了表征。使用可见光代替紫外线照射，测试了 MgO/TiO2 光催化剂对亚甲蓝 (MB) 染料的降解。MgO/TiO2-30 和 30 wt% Mg 前驱体在 120 分钟内实现了 99.7% 的最高光降解效率。还研究了煅烧温度对催化剂催化活性的影响。使用 HPLC 确认 MB 的降解。MgO/TiO2-30 的速率常数为 2.4 × 10-2 min-1，是速率常数为 6 的裸 P25-TiO2 速率常数的 4 倍。0 × 10−3 min−1。MgO/TiO2 优异的光催化活性是由于 MgO 与 10 nm 大小的 TiO2 结合形成了 MgO/TiO2 界面。提出了用于更好的电荷传输的化学计量/非化学计量氧化物界面的概念。评价光催化剂的可回收性。最后，还提出了暗示性的反应机理。