Abstract Multi metal based photocatalyst (CdO-MgO-Fe2O3) was synthesized via wet chemical approach i.e. co-precipitation method. The single transition metal oxides like CdO, MgO and Fe2O3 were also prepared for comparative studies. Structural elucidation of all prepared powder catalysts (CdO, MgO, Fe2O3 and CdO-MgO-Fe2O3) was conducted by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). XRD showed the presence of the MgO (cubic) – Fe2O3 (rhombohedral)– CdO (cubic) phase with an average crystallite size of MgO (9 nm), Fe2O3 (12 nm), CdO (23 nm). FTIR proved the existence of Mg–O, Fe2-O3 and Cd-O by distinctive vibrational bands at 772 cm−1, 581 cm−1 and 480 cm−1 respectively. UV–vis spectral studies showed that the bandgap for CdO-MgO-Fe2O3 nanocomposite was 1.76 eV which made it an efficient photocatalyst for use both in the UV and visible regions. Two probe I–V measurements confirmed the pure semiconducting behavior and possible formation of heterojunction in the CdO-MgO-Fe2O3 nanocomposite. The photocatalytic performance of the CdO-MgO-Fe2O3 nanocomposite with equal metal ion concentration of Mg, Fe and Cd at different pH values was explored by visible light illumination on methylene blue (MB) dye as a standard organic pollutant. The CdO-MgO-Fe2O3 nanocomposite with metal ion ratio 1:1:1 in an alkaline medium showed the maximum photocatalytic performance. The rate constant (kMB) value for the degradation of MB was ∼ 0.0820 min−1. The photocatalytic activity has been improved due to the effective decrease in the recombination rate of charge carriers. The possible mechanism for improvement of the photocatalytic performance using visible light illumination has also been suggested and discussed.

中文翻译：

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湿化学法制备的三金属氧化物纳米结构的结构、光学和光催化研究

摘要 采用湿化学法即共沉淀法合成了多金属基光催化剂(CdO-MgO-Fe2O3)。还制备了单一过渡金属氧化物，如 CdO、MgO 和 Fe2O3，用于比较研究。通过 X 射线衍射 (XRD) 和傅里叶变换红外光谱 (FTIR) 对所有制备的粉末催化剂 (CdO、MgO、Fe2O3 和 CdO-MgO-Fe2O3) 进行结构解析。XRD 显示存在 MgO（立方）- Fe2O3（菱形）-CdO（立方）相，平均晶粒尺寸为 MgO (9 nm)、Fe2O3 (12 nm)、CdO (23 nm)。FTIR 分别通过 772 cm-1、581 cm-1 和 480 cm-1 的独特振动带证明了 Mg-O、Fe2-O3 和 Cd-O 的存在。紫外-可见光谱研究表明，CdO-MgO-Fe2O3 纳米复合材料的带隙为 1。76 eV 使其成为一种高效的光催化剂，可用于紫外和可见光区域。两个探针 I-V 测量证实了纯半导体行为和可能在 CdO-MgO-Fe2O3 纳米复合材料中形成异质结。通过对作为标准有机污染物的亚甲蓝 (MB) 染料的可见光照射，探索了在不同 pH 值下具有相同金属离子浓度 Mg、Fe 和 Cd 的 CdO-MgO-Fe2O3 纳米复合材料的光催化性能。在碱性介质中，金属离子比为 1:1:1 的 CdO-MgO-Fe2O3 纳米复合材料表现出最大的光催化性能。MB 降解的速率常数 (kMB) 值为 ~ 0.0820 min-1。由于载流子复合率的有效降低，光催化活性得到了提高。