Photocatalytic purification technology has a unique application effect in the treatment of air and water pollution and has been used in many environmental pollution treatment processes. In the past research process, the main work is centered on the preparation and application of new high activity photocatalytic materials. After half a century of development and improvement, the current research focus is on the further industrial application of the technology. In this process, the choice of materials and the adaptability to the specific process is particularly important.
Photocatalytic technology and related products are mainly used in small-scale civil products and small-scale industrial production. The main factor restricting its application in large-scale industrial production is photocatalytic materials. Titanium-containing compounds are the main body of photocatalytic materials, among which the most important is titanium oxide. Titanate, which has attracted the attention of researchers, is a new type of photocatalytic materials with great application potential at present. Lanthanum titanate material has satisfactory performance in various environmental pollution purification processes, especially the use of visible light energy makes it have a low cost of use.
Lanthanum titanate belongs to ABO3 perovskite structure material, which is a new kind of synthetic functional ceramic powder. Can be used as piezoelectric materials, photoelectric materials, ferroelectric materials, etc. Because lanthanum titanate is a typical layered perovskite (A2B2O7) type composite metal oxide, it has the advantages of high catalytic activity, high light quantum efficiency and can efficiently use light energy, so it has a very wide range of applications in photohydrolysis of water for hydrogen production, organic decomposition, environmental governance and other aspects.
Traditional synthesis methods of lanthanum titanate generally adopt the traditional solid-phase high-temperature method, which not only has high energy consumption, but also takes a long time for sintering, resulting in large particle size and uneven distribution of the synthesized products, thus affecting its performance. How to synthesize products with high purity, small particle size and uniform distribution by economical and reasonable process route has become a key research topic for scientific research workers.
At present, there are many researches on lanthanum titanate, but most synthesis methods are not simple. Lanthanum titanate is a kind of metal oxide with perovskite structure. It has many excellent properties, such as room temperature conductivity and low preparation cost. These excellent properties of lanthanum titanate conductive thin film materials determine that the lanthanum titanate conductive thin film can be used not only as the bottom electrode of ferroelectric thin film, but also as the buffer layer of ferroconductive thin film with perovskite structure. Among many methods for preparing lanthanum titanate conductive thin films, chemical solution deposition has the advantages of simple preparation process, low reaction temperature and easy reaction.
Physical and chemical properties and structure
The lanthanum titanate crystal La2Ti2O7 belongs to the monoclinic system, with a perovskite-like structure, and the space group at room temperature is P21. Lanthanum titanate crystal has good ferroelectric, photocatalytic and electro-optic properties, and has a very wide application prospect in the field of light and electricity. It has a very high Curie temperature (1500℃) and a large coercive field (45kV/cm). It can be used in high temperature electro-optic equipment and information memory, such as high temperature frequency converter, ferroelectric random access memory (FREM), etc.
In recent years, microwave technology has been rapid development, in various fields of application is increasingly widespread, so the development of new high-performance microwave dielectric materials work is more and more attention by the vast number of researchers, lanthanum titanate crystal has a high dielectric constant (εr = 42-62), Because of its low dielectric temperature coefficient and dielectric loss (100kHz-1MHz), it has become a research hotspot at home and abroad as an important microwave dielectric material. At the same time, it also has good piezoelectric properties, can be used to make high temperature sensors and microwave piezoelectric devices.
In addition, lanthanum titanate crystals have excellent photocatalytic activity, and have good application prospects in water decomposition reaction, fuel cell and other energy conversion technologies. Especially in China, there are many kinds and abundant reserves of rare earth elements, which provide a unique platform for the study of lanthanum titanate crystal.
With the development of research, it has been found that lanthanum titanate crystals can be used as coating materials with excellent performance in the manufacturing of optoelectronic devices, such as display technology, imaging technology, light output and optical integration devices, etc. The lanthanum titanate crystal coating material has stable high refractive index, high homogeneity and high transmittance. At present, lanthanum titanate crystals as coating materials have been widely used in the manufacture of high-performance optoelectronic devices, but in this field in China is still in a blank state. As for the precision optical manufacturing platform, due to the lack of advanced materials, China is also in the production stage of low-end technology products.