Abstract

This study describes the synthesis of Cu/Nb₂O₅, Fe/Nb₂O₅, and Cu-Fe/Nb₂O₅ catalysts obtained by incorporating copper and/or iron metals into niobium pentoxide (Nb₂O₅). The new materials were characterized by the following techniques: Thermogravimetric Analysis (TA), surface and pore analysis, X-ray diffractometry (XRD), and Fourier Transform Infrared Spectroscopy (FT-IR). The catalyst was applied in the photocatalytic degradation of salicylic acid (SA). The influence of different parameters (calcined temperature, pH, and metal addition) on the photocatalytic reaction was evaluated. The results indicated that catalysts containing copper were more active and pH influenced the SA degradation process. SA removal results indicated that Cu/Nb₂O₅ photocatalyst presented a 1.5 fold higher degradation after 120 min in comparison to Cu-Fe/Nb₂O₅ and 4.6 fold higher than Fe/Nb₂O₅ catalyst, all them calcined at 400 °C. In tests carried out in the presence of formic acid, increasing the pH from about 3 to 7 allowed an almost 3.4-fold increase in SA degradation for the Cu-Fe/Nb₂O₅ catalyst calcined at 400 °C.

摘要

本研究描述了通过将铜和_/或铁金属掺入_五氧化二铌_{（Nb 2} O ₅）。通过以下技术对新材料进行表征：热重分析 (TA)、表面和孔分析、X 射线衍射 (XRD) 和傅里叶变换红外光谱 (FT-IR)。该催化剂应用于水杨酸（SA）的光催化降解。评估了不同参数（煅烧温度、pH 和金属添加量）对光催化反应的影响。结果表明，含铜催化剂活性更高，pH影响SA降解过程。SA去除结果表明，与Cu-Fe/Nb ₂ O _{5相比，Cu/Nb 2} O ₅光催化剂在120分钟后的降解率高出1.5倍，比Fe/Nb ₂ O高出4.6倍₅催化剂，均在400℃下煅烧。在甲酸存在下进行的测试中，将 pH 从约 3 提高到 7 可使在 400°C 煅烧的 Cu-Fe/Nb ₂ O _{5催化剂的 SA 降解增加近 3.4 倍。}