Abstract Oil spill from explosion of oil wells and tankers threatens the life of sea creatures. Photocatalytic oxidation of oil spill is a promising way due to its low cost, complete conversion and the capability of using free and abundant sunlight. For better interaction between oil, photocatalyst and the light, it is recommended to use floating photocatalysts. In this research, recycled drinking bottles made of polyethylene terephthalate (PET) were used as a floating support for C3N4 and ZnO photocatalysts. ZnO–C3N4/r-PET composite with various amounts of ZnO (0, 5, 10 and 15 wt.%) were synthesized and characterized by means of X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM-EDX), N2-sorption isotherm (BET-BJH), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR) and UV–vis diffuse reflectance spectroscopy (UV–Vis DRS). The as-prepared ZnO–C3N4/r-PET nanocomposites were tested for the photocatalytic degradation of benzene. The results show that by increasing the amount of ZnO, the particle size decreased, size distribution narrowed and a more homogenous morphology was observed. Moreover, pore volume, pore diameter and BET surface area increased. In details, ZnO crystallite size reduced from 32 nm in ZnO–C3N4/r-PET nanocomposite with 5 wt.% of ZnO to 18 nm in similar nanocomposite with 15 wt.% of ZnO. Increasing the ZnO amount, broadened the band gap but enhanced the light absorption in visible and UV regions. Good interaction between C3N4 and ZnO was confirmed in TEM image. The highest degradation performance was obtained in the presence of 15 wt.% of ZnO. In fact by decreasing the amount of ZnO in the ZnO–C3N4/r-PET composite, the photodegradation rate decreased significantly. Influence of operating parameters like pH, catalyst loading, benzene volume percent and simulated sea conditions on photodegradation of floating benzene were also studied in details.

中文翻译：

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漂浮回收 PET 瓶上的 ZnO-C3N4 太阳能光驱动纳米光催化剂作为溢油降解的支持

摘要 油井和油轮爆炸造成的石油泄漏威胁着海洋生物的生命。溢油光催化氧化具有成本低、转化完全、可利用自由充足的阳光等优点，是一种很有前景的方法。为了油、光触媒和光之间更好的相互作用，建议使用浮动光触媒。在这项研究中，由聚对苯二甲酸乙二醇酯 (PET) 制成的回收饮料瓶用作 C3N4 和 ZnO 光催化剂的漂浮载体。合成了含有不同量 ZnO（0、5、10 和 15 wt.%）的 ZnO-C3N4/r-PET 复合材料，并通过 X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM-EDX）表征, N2 吸附等温线 (BET-BJH)，透射电子显微镜 (TEM)，傅里叶变换红外光谱 (FT-IR) 和紫外-可见漫反射光谱 (UV-Vis DRS)。测试制备的 ZnO-C3N4/r-PET 纳米复合材料对苯的光催化降解。结果表明，随着ZnO用量的增加，颗粒尺寸减小，尺寸分布变窄，并且观察到更均匀的形态。此外，孔体积、孔径和 BET 表面积增加。具体而言，ZnO 晶粒尺寸从含有 5 wt.% ZnO 的 ZnO-C3N4/r-PET 纳米复合材料中的 32 nm 减小到含有 15 wt.% ZnO 的类似纳米复合材料中的 18 nm。增加 ZnO 的量，加宽了带隙，但增强了可见光和紫外区的光吸收。在 TEM 图像中证实了 C3N4 和 ZnO 之间的良好相互作用。在 15 wt.% ZnO 的存在下获得了最高的降解性能。事实上，通过降低 ZnO-C3N4/r-PET 复合材料中 ZnO 的含量，光降解率显着降低。还详细研究了pH值、催化剂负载量、苯体积百分比和模拟海况等操作参数对漂浮苯光降解的影响。