Rodrigues Ana Sofia, Ciríaco Lurdes, Pacheco Maria José, Fernandes Annabel, Mogo Sandra, Lopes Ana
Fiber Materials and Environmental Technologies (FibEnTech-UBI), Universidade da Beira Interior, R. Marquês de D'Ávila e Bolama, 6201-001 Covilhã, Portugal.
Department of Physics, Universidade da Beira Interior, 6201-001 Covilhã, Portugal.
Nanomaterials (Basel). 2021 Nov 21;11(11):3142. doi: 10.3390/nano11113142.
Perovskites of the (La,Ba)(Fe,Ti)O family were prepared, characterized, and utilized as heterogeneous photocatalysts, activated by natural sunlight, for environmental remediation of Acid Orange 7 (AO7) aqueous solutions. Catalysts were prepared by the ceramic (CM) and the complex polymerization (CP) methods and characterized by XRD, SEM, EDS, and band gap energy. It was found that catalytic properties depend on the synthesis method and annealing conditions. In the photocatalytic assays with sunlight, different AO7 initial concentrations and perovskite amounts were tested. During photocatalytic assays, AO7 and degradation products concentrations were followed by HPLC. Only photocatalysis with BaFeO-CM and BaTiO-CP presented AO7 removals higher than that observed for photolysis. However, photolysis leads to the formation of almost exclusively amino-naphthol and sulfanilic acid, whereas some of the perovskites utilized form less-toxic compounds as degradation products, such as carboxylic acids (CA). Partial substitution of Ba by La in BaTiO-CM does not produce any change in the photocatalytic properties, but the replacement of Ti by Fe in the LaBaTiO leads to reduced AO7 removal rate, but with the formation of CAs. The best AO7 removal (92%) was obtained with BaFeO-CM (750 mg L), after 4 h of photocatalytic degradation with solar radiation.
制备了(La,Ba)(Fe,Ti)O族钙钛矿，对其进行了表征，并将其用作多相光催化剂，在自然阳光照射下对酸性橙7（AO7）水溶液进行环境修复。通过陶瓷法（CM）和络合聚合法（CP）制备催化剂，并通过XRD、SEM、EDS和带隙能量对其进行表征。发现催化性能取决于合成方法和退火条件。在阳光光催化试验中，测试了不同的AO7初始浓度和钙钛矿用量。在光催化试验过程中，通过HPLC跟踪AO7和降解产物的浓度。只有BaFeO-CM和BaTiO-CP的光催化表现出比光解更高的AO7去除率。然而，光解几乎只导致氨基萘酚和磺胺酸的形成，而一些使用的钙钛矿形成毒性较小的化合物作为降解产物，如羧酸（CA）。在BaTiO-CM中用La部分取代Ba不会使光催化性能发生任何变化，但在LaBaTiO中用Fe取代Ti会导致AO7去除率降低，但会形成CAs。在用太阳辐射进行4小时光催化降解后，使用BaFeO-CM（750 mg/L）获得了最佳的AO7去除率（92%）。
