Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador.
Ingeniería Química, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador.
Int J Mol Sci. 2023 Feb 14;24(4):3780. doi: 10.3390/ijms24043780.
Cyanide is a highly toxic compound that can pose serious health problems to both humans and aquatic organisms. Therefore, the present comparative study focuses on the removal of total cyanide from aqueous solutions by photocatalytic adsorption and degradation methods using ZnTiO (ZTO), La/ZnTiO (La/ZTO), and Ce/ZnTiO (Ce/ZTO). The nanoparticles were synthesized by the sol-gel method and characterized by X-ray powder diffractometry (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Diffuse reflectance spectroscopy (DRS), and Specific surface area (SSA). The adsorption equilibrium data were fitted to the Langmuir and Freundlich isotherm models. Adsorption kinetics were also evaluated using the pseudo-first-order and pseudo-second-order models and the intraparticle diffusion model. Likewise, the photodegradation of cyanide under simulated sunlight was investigated and the reusability of the synthesized nanoparticles for cyanide removal in aqueous systems was determined. The results demonstrated the effectiveness of doping with lanthanum (La) and cerium (Ce) to improve the adsorbent and photocatalytic properties of ZTO. In general, La/ZTO showed the maximum percentage of total cyanide removal (99.0%) followed by Ce/ZTO (97.0%) and ZTO (93.6%). Finally, based on the evidence of this study, a mechanism for the removal of total cyanide from aqueous solutions using the synthesized nanoparticles was proposed.
氰化物是一种剧毒化合物，会对人类和水生生物造成严重的健康问题。因此，本比较研究专注于使用 ZnTiO（ZTO）、La/ZnTiO（La/ZTO）和 Ce/ZnTiO（Ce/ZTO）通过光催化吸附和降解方法从水溶液中去除总氰化物。纳米粒子通过溶胶-凝胶法合成，并通过 X 射线粉末衍射（XRD）、扫描电子显微镜（SEM）、能谱（EDS）、漫反射光谱（DRS）和比表面积（SSA）进行了表征。吸附平衡数据拟合了 Langmuir 和 Freundlich 等温吸附模型。还使用准一级和准二级动力学模型以及内扩散模型评估了吸附动力学。同样，研究了模拟太阳光下氰化物的光降解，并确定了合成纳米粒子在水溶液中去除氰化物的可重复使用性。结果表明，掺杂镧（La）和铈（Ce）可以有效提高 ZTO 的吸附和光催化性能。总的来说，La/ZTO 表现出最高的总氰化物去除率（99.0%），其次是 Ce/ZTO（97.0%）和 ZTO（93.6%）。最后，根据本研究的证据，提出了使用合成纳米粒子从水溶液中去除总氰化物的机理。
