Mixed perovskite- and mullite-type bandgap tailored visible light photocatalysts for wastewater purification

用于废水净化的混合钙钛矿型和莫来石型带隙定制可见光光催化剂

• 批准号: 461295486
• 负责人: Professor Dr. Thorsten Michael Gesing
• 金额: --
• 依托单位: Arbeitsgruppe Neurobiochemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/461295486?language=en
• 关键词: Mixed; perovskite; mullite; type; bandgap

The proposed project optimizes narrow bandgap materials for enhanced photocatalytic activity by using a combination of perovskite- and mullite-type compounds. Perovskite-type BiFeO3 and mullite-type Bi2Fe4O9 structures exhibit both high photocatalytic activities and oxidize organic pollutants, as in wastewater, into carbon dioxide and mineral acids under visible light irradiation. It is possible to substitute Fe3+ with other cations like Al3+, Ga3+ and Mn3+, also showing photocatalytic activity. Therefore, it bears a critical importance to investigate the rich set of solid solutions, by replacing the M-cations (M = Al3+, Ga3+, Mn3+) systematically, to establish a relation between composition, bandgap and the highest possible photocatalytic activity. The materials to be investigated are mainly Bi2M4O9 structures but explorative work on the Bi2Mn4O10 structure and related structures/compositions are as well planned. Our recent experiments showed that designing quantum-sized crystallites led to a co-crystallization of metastable (Bi1-xFex)FeO3 and Bi2Fe4O9. This finding offers the possibility to form two different photocatalytic active structures within one matrix leading to pseudo-single exciton stabilization analogous to that of well-known TiO2 rutile/anatase mixture. Using different synthesis routes such as the glycerin method, polyol method, PVA method and the flame spray pyrolysis different particle sizes, crystallite sizes as well as morphologies and perovskite-/mullite-type ratios could be produced. The materials will be characterized by diffuse reflectance UV/Vis spectroscopy, X-ray powder diffraction (XRPD), infrared (IR) and Raman spectroscopy, dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and microscopic methods (TEM, SEM and EDX). For selected samples of good quality, the photocatalytic activity will be determined. For selected samples of good quality, the photocatalytic activity is determined, for which a corresponding flow cell is built and used as a test system. The resulting decomposition products are examined for their toxicity as well as by potential material abrasion.

该项目通过结合使用钙钛矿型和莫来石型化合物来优化窄带隙材料，以增强光催化活性。钙钛矿型BiFeO3和莫来石型Bi2Fe4O9结构表现出高光催化活性，并在可见光照射下将废水中的有机污染物氧化成二氧化碳和无机酸。可以用 Al3+、Ga3+ 和 Mn3+ 等其他阳离子取代 Fe3+，也表现出光催化活性。因此，通过系统地替换M-阳离子（M = Al3+、Ga3+、Mn3+）来研究丰富的固溶体，以建立组成、带隙和最高可能的光催化活性之间的关系至关重要。待研究的材料主要是Bi2M4O9结构，但对Bi2Mn4O10结构和相关结构/成分的探索工作也在计划中。我们最近的实验表明，设计量子尺寸的微晶导致了亚稳态 (Bi1-xFex)FeO3 和 Bi2Fe4O9 的共结晶。这一发现提供了在一个基质内形成两种不同光催化活性结构的可能性，从而产生类似于众所周知的 TiO2 金红石/锐钛矿混合物的伪单激子稳定性。采用不同的合成路线，如甘油法、多元醇法、PVA法和火焰喷射热解法，可以生产不同的粒径、微晶尺寸以及形态和钙钛矿/莫来石型比例。这些材料将通过漫反射紫外/可见光谱、X射线粉末衍射（XRPD）、红外（IR）和拉曼光谱、动态光散射（DLS）、小角度X射线散射（SAXS）和显微方法（ TEM、SEM 和 EDX）。对于选定的优质样品，将测定其光催化活性。对于选定的优质样品，确定光催化活性，为此构建相应的流动池并用作测试系统。检查所得分解产物的毒性以及潜在的材料磨损。