Franco Peláez Daynahi, Rodríguez S Julia Liliana, Poznyak Tatyana, Martínez Gutiérrez Hugo, Andraca Adame J Alberto, Lartundo Rojas Luis, Ramos Torres Claudia Jazmín
Laboratorio de Investigación en Ingeniería Química Ambiental, ESIQIE-Instituto Politécnico Nacional Zacatenco Ciudad de México 07738 Mexico
Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional Zacatenco Ciudad de México 07738 Mexico.
RSC Adv. 2024 Jan 26;14(6):3923-3935. doi: 10.1039/d3ra07316e. eCollection 2024 Jan 23.
This research focuses on the synthesis of NiO and CeO thin films using spray pyrolysis for the removal of benzoic acid using ozone as an oxidant. The results indicate that the addition of CeO films significantly enhances the mineralization of benzoic acid, achieving a rate of over 80% as the CeO films react with ozone to produce strong oxidant species, such as hydroxyl radicals, superoxide radicals, and singlet oxygen as demonstrated by the presence of quenchers in the reaction system. The difference in catalytic activity between NiO and CeO films was analyzed XPS technique; specifically, hydroxyl oxygen groups in the CeO film were greater in number than those in the NiO film, thus benefitting catalytic oxidation as these species are considered active oxidation sites. The effects of nozzle-substrate distances and deposition time during the synthesis of the films on benzoic acid removal efficiency were also explored. Based on XRD characterization, it was established that the NiO and CeO films were polycrystalline with a cubic structure. NiO spherical nanoparticles were well-distributed on the substrate surface, while some pin holes and overgrown clusters were observed in the CeO films according to the SEM results. The stability of the CeO films after five consecutive cycles confirms their reusability. The retrieval of films is easy because it does not require additional separation methods, unlike the catalyst in powder form. The obtained results indicate that the CeO films have potential application in pollutant removal from water through catalytic ozonation.
本研究聚焦于采用喷雾热解法合成氧化镍（NiO）和氧化铈（CeO）薄膜，以臭氧作为氧化剂用于去除苯甲酸。结果表明，添加CeO薄膜显著提高了苯甲酸的矿化程度，当CeO薄膜与臭氧反应生成强氧化性物种（如羟基自由基、超氧自由基和单线态氧，反应体系中猝灭剂的存在证明了这些物种的存在）时，矿化率超过80%。利用XPS技术分析了NiO和CeO薄膜之间催化活性的差异；具体而言，CeO薄膜中的羟基氧基团数量多于NiO薄膜，由于这些物种被认为是活性氧化位点，因此有利于催化氧化。还探究了薄膜合成过程中喷嘴与基板的距离和沉积时间对苯甲酸去除效率的影响。基于XRD表征，确定NiO和CeO薄膜为具有立方结构的多晶薄膜。根据SEM结果，NiO球形纳米颗粒在基板表面分布良好，而在CeO薄膜中观察到一些针孔和过度生长的团聚物。CeO薄膜经过连续五个循环后的稳定性证实了其可重复使用性。与粉末形式的催化剂不同，薄膜的回收很容易，因为它不需要额外的分离方法。所得结果表明，CeO薄膜在通过催化臭氧化去除水中污染物方面具有潜在应用。
