NO S-g-C3N4/MgAl-CLDH纳米复合物的降解能力及其在基于水泥的材料中的潜在应用
Zhengxian Yang1, Xiaoli Xiong1, Xueyuan Yan1
1Joint International Research Laboratory of Deterioration and Control of Costal and Marine Infrastructures and Materials, College of Civil Engineering, Fuzhou University Fuzhou 350108 China y.zhang@fzu.edu.cn.
RSC advances
|July 20, 2023
概括
一种新的S-g-C3N4/MgAl-CLDH纳米复合材料有效降解光催化水泥砂中的NOX. 这种稳定的材料显示了100%的NOX降解和与基于水泥的应用程序的良好兼容性.
科学领域:
- 材料科学 材料科学 材料科学
- 环境科学 环境科学
- 化学 化学 化学
背景情况:
- 光催化材料对于环境修复至关重要.
- 氧化 (NOx) 是主要的空气污染物,导致烟雾和酸雨.
- 开发稳定高效的光催化剂,将其整合到建筑材料中是一个持续的挑战.
研究的目的:
- 为了合成和描述一种新的S-g-C3N4/MgAl-CLDH光催化纳米复合材料.
- 为了评估纳米复合材料的NOx降解效率及其融入水泥砂.
- 评估纳米复合材料在水泥环境中的化学稳定性和兼容性.
主要方法:
- 在S-g-C3N4/MgAl-CLDH纳米复合材料的合成.
- 纳米复合材料通过内部混合和涂层将纳米复合材料纳入水泥砂.
- 在可见光照射下进行光催化NOx降解测试.
- 使用模拟混凝土孔溶液评估化学稳定性.
- 对材料属性的分析,包括带隙,再组合率和表面积.
主要成果:
- 与S-g-C3N4相比,S-g-C3N4/MgAl-CLDH具有更窄的带隙 (2.45 eV),减少了电子孔重组,以及更大的表面积 (36.86 m2 g-1).
- 纳米复合材料在21分钟内实现了100%的NOx降解,超过了S-g-C3N4 (81.5%).
- 该材料在模拟的混凝土孔溶液中表现出良好的稳定性,降解效率仅下降了5%.
- 内部混合砂显示,随着纳米复合物剂量的增加,NOx降解的增强,而过度涂层降低了效率.
结论:
- 这种S-g-C3N4/MgAl-CLDH纳米复合材料是NOx降解的高效和稳定的光催化剂.
- 它成功地集成到水泥砂中,为创建自净化建筑材料提供了一个有希望的方法.
- 该研究证实了该材料与基于水泥的系统的兼容性,为实际的环境应用铺平了道路.
相关概念视频
01:24Hydration of Cement
290
Hydration of cement is a chemical reaction between cement particles and water. This process occurs primarily through two mechanisms: through-solution and topochemical. In the through-solution process, anhydrous compounds dissolve into their constituents, hydrates form in the solution, and then precipitate from the supersaturated solution. The topochemical process involves solid-state reactions at the cement particle surface. The through-solution process dominates the topochemical process at the...
290
01:21Types of Cement I
155
Portland cement comes in several types, each with distinct properties and applications based on their chemical composition and hydration characteristics:
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
155
01:20Strength of Cement
167
Strength tests for cement are not performed directly on neat cement paste due to difficulty in obtaining consistent, reliable specimens. Instead, cement is typically tested in the form of cement-sand mortar.
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
167
01:22Types of Cement II
132
Portland blast-furnace cement is made by blending Portland cement clinker with granulated blast-furnace slag, which accounts for 25 to 65 percent of the cement's weight. Despite its similarities to ordinary Portland (Type I) cement in terms of fineness and setting times, its early strength is lower, though it achieves comparable strength later on. It's particularly suited for mass concrete structures and marine environments due to its lower heat of hydration and superior sulfate...
132
01:29Strength and Heat of Hydration
274
The hydration of cement is an exothermic reaction in which heat is generated as cement hydrates. This heat of hydration is critical to cement's strength development. The rate at which this heat is generated affects the temperature rise, with a majority of the heat being released early in the hydration process, half within the first three days, and about 75% within the first week.
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
274
01:15Fineness of Cement
162
The fineness of cement directly influences the rate of hydration, as the hydration begins at the surface of the cement particles. In addition to hydration, the fineness of cement is vital for various properties of concrete including workability, gypsum requirement, and long-term behavior. The fineness of cement is represented in terms of the specific surface of cement which is typically measured in square meters per kilogram, with several methods available for this determination.
Direct...
Direct...
162