Abstract

In this study, the photocatalytic efficiency of scoria-Ni/TiO₂ nanoparticles is evaluated for methyl orange removal under both the ultraviolet (UV) and sunlight irradiations. The synthesized catalysts are characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectra (DRS), scanning electron microscope (SEM), and energy dispersive X-ray analysis (EDAX) analysis. According to the results, the absorption edge of TiO₂ alternated to visible light successfully, and the SEM and EDAX analysis approved that the particles, which are in nano-size, doped on the scoria. The effect of pH, catalyst dosage, methyl orange concentration, and contact time on efficiency was assessed. The initial experiment revealed that 0.05% and 0.1% of nickel have more efficiency while using the sun and UV light sources, respectively. In a 50-ml lab-scale reactor, methyl orange removal efficiency by scoria-Ni/TiO₂ was 95.89 and 93.97% under UV and sunlight irradiation, respectively, within 45 min contact time while it was 26.7 and 45.9% under the sun and UV light irradiation, respectively, for commercial TiO₂. In addition, the reaction kinetics followed the Langmuir–Hinshelwood model. Finally, radical production and catalytic activity of Ni/TiO₂ verified by significant decrease in removal efficiency due to surface and solution radical scavengers addition.

Graphic abstract

中文翻译：

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固定的二氧化铈-Ni / TiO 2纳米粒子对光催化降解甲基橙的优化

摘要

在这项研究中，评估了氧化ria-Ni / TiO ₂纳米颗粒在紫外（UV）和日光照射下对甲基橙去除的光催化效率。使用X射线衍射（XRD），傅里叶变换红外光谱（FTIR），漫反射光谱（DRS），扫描电子显微镜（SEM）和能量色散X射线分析（EDAX）分析对合成的催化剂进行表征。根据结果​​，TiO ₂的吸收边缘成功地转换为可见光，并且SEM和EDAX分析批准将纳米尺寸的颗粒掺杂在氧化渣上。评估了pH，催化剂用量，甲基橙浓度和接触时间对效率的影响。初始实验表明，分别使用阳光和紫外线光源时，镍的0.05％和0.1％具有更高的效率。在50毫升实验室规模的反应器中，在45分钟的接触时间内，紫外和日光照射下，经scoria-Ni / TiO ₂去除甲基橙的效率_分别为95.89和93.97％，而在阳光和阳光下则分别为26.7和45.9％。分别用于商用TiO _2的紫外线照射。此外，反应动力学遵循Langmuir-Hinshelwood模型。最后，由于表面和溶液自由基清除剂的加入，去除效率显着降低，证实了Ni / TiO _2的自由基产生和催化活性。

图形摘要