Guel-Nájar Norma Araceli, Rios-Hurtado Jorge Carlos, Muzquiz-Ramos Elia Martha, Dávila-Pulido Gloria I, González-Ibarra Adrián A, Pat-Espadas Aurora M
Facultad de Metalurgia, Universidad Autónoma de Coahuila, Carretera 57 Km 5, Monclova 25710, Coahuila, Mexico.
Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Blvd. Venustiano Carranza S/N, República, Saltillo 25280, Coahuila, Mexico.
Materials (Basel). 2023 Apr 15;16(8):3127. doi: 10.3390/ma16083127.
Biochar is a carbonaceous and porous material with limited adsorption capacity, which increases by modifying its surface. Many of the biochars modified with magnetic nanoparticles reported previously were obtained in two steps: first, the biomass was pyrolyzed, and then the modification was performed. In this research, a biochar with FeO particles was obtained during the pyrolysis process. Corn cob residues were used to obtain the biochar (i.e., BCM) and the magnetic one (i.e., BCM). The BCM biochar was synthesized by a chemical coprecipitation technique prior to the pyrolysis process. The biochars obtained were characterized to determine their physicochemical, surface, and structural properties. The characterization revealed a porous surface with a 1013.52 m/g area for BCM and 903.67 m/g for BCM. The pores were uniformly distributed, as observed in SEM images. BCM showed FeO particles on the surface with a spherical shape and a uniform distribution. According to FTIR analysis, the functional groups formed on the surface were aliphatic and carbonyl functional groups. Ash content in the biochar was 4.0% in BCM and 8.0% in BCM; the difference corresponded to the presence of inorganic elements. The TGA showed that BCM lost 93.8 wt% while BCM was more thermally stable due to the inorganic species on the biochar surface, with a weight loss of 78.6%. Both biochars were tested as adsorbent materials for methylene blue. BCM and BCM obtained a maximum adsorption capacity (q) of 23.17 mg/g and 39.66 mg/g, respectively. The obtained biochars are promising materials for the efficient removal of organic pollutants.
生物炭是一种吸附能力有限的碳质多孔材料，可通过修饰其表面来提高吸附能力。先前报道的许多用磁性纳米颗粒修饰的生物炭是分两步制备的：首先，将生物质热解，然后进行修饰。在本研究中，在热解过程中获得了含有FeO颗粒的生物炭。使用玉米芯残渣来制备生物炭（即BCM）和磁性生物炭（即BCM）。BCM生物炭在热解过程之前通过化学共沉淀技术合成。对所获得的生物炭进行表征以确定其物理化学、表面和结构性质。表征结果显示，BCM的表面具有多孔结构，比表面积为1013.52 m²/g，BCM为903.67 m²/g。如扫描电子显微镜图像所示，孔隙分布均匀。BCM表面显示出球形且分布均匀的FeO颗粒。根据傅里叶变换红外光谱分析，表面形成的官能团为脂肪族和羰基官能团。生物炭中的灰分含量，BCM为4.0%，BCM为8.0%；这种差异对应于无机元素的存在。热重分析表明，BCM失重93.8 wt%，而BCM由于生物炭表面的无机物种而具有更高的热稳定性，失重78.6%。两种生物炭均作为亚甲基蓝的吸附材料进行了测试。BCM和BCM的最大吸附容量（q）分别为23.17 mg/g和39.66 mg/g。所获得的生物炭是用于高效去除有机污染物的有前景的材料。
