Fe复合ZnO催化剂制备及其光催化固氮性能研究

Preparation of Fe Composite ZnO Catalyst and Its Photocatalytic Performance for Nitrogen Fixation

摘要: 本文以ZnSO₄·7H₂O与FeSO₄·7H₂O为原料采用沉淀还原法制备了不同含量Fe复合ZnO催化剂。通过X射线衍射仪(XRD)、紫外–可见漫反射(UV-Vis)和电化学组抗图、肖特基等表征手段对催化剂的物相、吸光特性、光生电子电阻和移动性能等进行了研究。研究结果发现随Fe含量的增加，复合ZnO催化剂光吸收强度逐渐增加，能带间隙逐渐减小，光生电子转移阻力减小，移动速度增加，光生电子空穴发生复合率降低，越容易活化氮分子与氢离子生成铵离子，复合ZnO催化剂光催化固氮性能逐渐升高。当Zn与Fe物质的量比为4:6，干燥温度为90℃时，制备的Fe复合ZnO催化剂固氮性能最好，NH₄ 浓度达到了12.8175 μg·g_cat⁻¹。

Abstract: In this paper, ZnSO₄·7H₂O and FeSO₄·7H₂O were used as raw materials to prepare composite ZnO catalysts with different contents of Fe by precipitation reduction method. The phase, absorption properties, photoelectronic resistance and mobility of the catalysts were studied by X-ray diffractometry (XRD), UV-Vis, electrochemical reactance diagram and Schottky characterization methods. The results show that with the increase of Fe content, the photo absorption strength of the composite ZnO catalyst increases gradually, the band gap decreases gradually, the photogenerated electron transfer resistance decreases, the movement speed increases, the photogenerated electron does not recombine with the hole, the easier it is to activate nitrogen molecules and hydrogen ions to form ammonium ions, and the photocatalytic nitrogen fixing performance of the composite ZnO catalyst increases gradually. When the dosage ratio of Zn to Fe is 4:6 and the drying temperature is 90˚C, the nitrogen fixation performance of Fe composite ZnO catalyst is the best, and the concentration of NH₄ reaches 12.8175 μg·g_cat⁻¹.