Abstract This work explores the development of hybrid Nb2O5/carbon xerogel photocatalysts. The precursor materials used, such as tannin and recycled niobium scraps, enhance the economic and environmental aspects of the synthesis. The materials were characterized by diffuse reflectance spectroscopy, scanning electron microscopy, dispersive energy spectroscopy, infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The photocatalytic action of the material was evaluated by methylene blue decomposition as determined by UV–visible spectroscopy. Anhydrous niobium oxide has a hexagonal structure. The X-ray profiles of the materials developed (XC-wNb) are similar to Nb2O5, confirming the presence of inorganic oxide in the matrix of these composites. The chemical elements that compose the samples are homogeneously distributed on the surface of the samples, confirming the dispersion of the oxide in the carbonaceous matrix. The XC-wNb absorbs radiation in a considerably wider range than inorganic oxides, in this case, for the entire wavelength range used in the experiments, thereby suggesting the synergistic effect of xerogel and niobium oxide on the optical properties of the XC-wNb samples. All XC-wNb presented photocatalytic activity under visible radiation, evidencing the beneficial coupling effect on the photocatalytic properties of the material. The XC-24Nb was the most effective photocatalyst at the wavelength used due its composition, morphological and photochemical properties. The methylene blue photodegradation is controlled to a greater extent by reaction with the OH • radical. The XC-24Nb also presents high stability and reusability, which are optimal properties for industrial application.

中文翻译：

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Nb/C 比对新型廉价 Nb 2 O 5 /碳干凝胶复合材料的形态、结构、光学和光催化性能的影响

摘要 这项工作探索了混合 Nb2O5/碳干凝胶光催化剂的开发。所使用的前体材料，如单宁和回收的铌废料，提高了合成的经济和环境方面。通过漫反射光谱、扫描电子显微镜、色散能谱、红外光谱、拉曼光谱和X射线衍射对材料进行了表征。该材料的光催化作用通过紫外-可见光谱法测定的亚甲基蓝分解来评估。无水氧化铌具有六方结构。开发的材料 (XC-wNb) 的 X 射线分布类似于 Nb2O5，证实这些复合材料的基体中存在无机氧化物。构成样品的化学元素均匀分布在样品表面，证实了氧化物在碳质基质中的分散。在这种情况下，对于实验中使用的整个波长范围，XC-wNb 在比无机氧化物更宽的范围内吸收辐射，从而表明干凝胶和氧化铌对 XC-wNb 样品的光学性质的协同作用。所有 XC-wNb 在可见光辐射下都表现出光催化活性，证明了对材料光催化性能的有益耦合作用。XC-24Nb 因其成分、形态和光化学性质而成为所用波长下最有效的光催化剂。亚甲蓝光降解通过与 OH • 自由基反应得到更大程度的控制。