碱活化材料(AAMs)是利用低成本工业固体废物生产的环保粘合剂。它们具有良好的机械和物理性能,并且它们的制造与低环境影响和减少温室气体排放有关。因此,最近,AAM 在环境修复等新应用中受到了相当大的关注。在这里,用Bi 2 O 2 CO 3和Bi 2 O 3 /Bi 2 O 2 CO 3功能化的碱活化材料异质结构被设计、制造和评估为用于环境修复的光催化剂。为了证明这些复合材料(或材料系统)的适用性,研究了三种具有代表性的光催化反应:(i)自清洁,(ii)空气净化和(iii)抗菌活性。光催化剂采用缺溶剂法和水热法合成,促进了片状和花状颗粒的形成。Bi 2 O 3 /Bi 2 O 2 CO 3异质结构表现出较低的带隙和更有效的电荷转移,而 Bi 2 O 2 CO 3光催化剂显示出更高的表面积(28 m 2 /g)和更小的微晶尺寸。用光催化剂功能化的碱活化材料显示出粗糙的表面(~1μm),具有紧密的微观结构,由几个与碱性硅酸盐相关的棒状颗粒组成,维氏硬度约为 30-50 MPa。AAM 表现出从其表面去除亚甲蓝(~30%)的活性,这证明了它们的自清洁活性。此外,AAMs 表现出显着的去除空气中甲醛的活性,照射 3 小时后效率高达 81%。此外,通过抑制大肠杆菌沙门氏菌的生长,研究了 AAMs 的抗菌活性。和金黄色葡萄球菌, 在辐照下。对细菌的研究表明,在培养基中 24 小时后,AAM 对这些微生物表现出抑制区(大肠杆菌,2.14-3.00 厘米;沙门氏菌,3.01-3.31 厘米;金黄色葡萄球菌,2.67-3.31 厘米) . 在 AAM 中进行了加速老化测试,以保证其在使用寿命内的效率。结果证实了在老化处理 300 小时后,用异质结构光催化剂功能化的 AAM 的光催化活性。这些结果证明了通过应用由工业废物和 Bi 2 O 3 /Bi 2制造的 AAM 产生自清洁、空气净化和抗菌表面的可能性O 2 CO 3光催化剂。
"点击查看英文标题和摘要"
Photocatalytic performance of alkali-activated materials functionalized with β-Bi2O3/Bi2O2CO3 heterostructures for environmental remediation
Alkali-activated materials (AAMs) are environmentally friendly binders produced with industrial solid wastes of low cost. They have good mechanical and physical properties, and their manufacture is associated with a low environmental impact and reduced greenhouse emissions. Thus, recently, AAMs have received considerable attention for new applications, such as environmental remediation. Here, alkali-activated materials functionalized with Bi2O2CO3 and Bi2O3/Bi2O2CO3 heterostructures were designed, fabricated, and evaluated as photocatalysts for environmental remediation. To demonstrate the applicability of these composites (or materials system), three representative photocatalytic reactions: (i) self-cleaning, (ii) air purification, and (iii) antimicrobial activity, were investigated. The photocatalysts were synthesized by solvent-deficient and hydrothermal methods, which promoted the formation of particles with flake and flower morphologies. Bi2O3/Bi2O2CO3 heterostructures exhibited lower band gaps and a more efficient charge transfer, whereas the Bi2O2CO3 photocatalysts showed higher surface area (28 m2/g) and smaller crystallite size. The alkali-activated materials functionalized with the photocatalysts showed a rough surface (∼1 μm) with a compact microstructure composed of several rod-like particles related to alkaline silicates with a Vickers hardness around 30–50 MPa. AAMs showed activity to remove methylene blue (∼30%) from their surface, which evidenced their self-cleaning activity. In addition, the AAMs showed remarkable activity to remove formaldehyde from the air, reaching efficiencies up to 81% after 3 h of irradiation. Furthermore, the antimicrobial activity of the AAMs was studied by means of the growth inhibition of Escherichia coli, Salmonella sp. and Staphylococcus aureus, under irradiation. The study with bacteria showed that, after 24 h in the culture medium, the AAMs exhibited inhibition zones against these microorganisms (Escherichia coli, 2.14–3.00 cm; Salmonella sp., 3.01–3.31 cm; and Staphylococcus aureus, 2.67–3.31 cm). Accelerated weathering tests were performed in the AAMs to guarantee their efficiency over their lifetime. The results confirm the photocatalytic activity of the AAMs functionalized with the heterostructured photocatalysts after 300 h of aging treatment. These results demonstrated the possibility of generating self-cleaning, air-depolluting, and antimicrobial surfaces by applying the AAMs fabricated with industrial wastes and Bi2O3/Bi2O2CO3 photocatalysts.