Donghua University has made new progress in preparation of high quality photocatalyst and photocatalytic degradation of tetracycline water pollution

Recently, Professor Xue Shaolin's research group of Donghua University School of science cooperated with City University of Hong Kong to make new progress in the field of preparing high-quality photocatalyst and photocatalytic degradation of tetracycline water pollution The related achievements are as follows: "synthesis of tetragonal prismatic γ - in 2 se 3 nanostructures with preliminary {110} facets and photocatalytic degradation of tetracycline", Doi: 10.1016/j.apcatb.2019.118218), published in applied catalyst B - environmental, a famous journal in the field of environment and chemical industry The first author of this paper is Wei Xiaofan, a postgraduate student, and the corresponding author is Professor Xue Shaolin In recent years, with the rapid development of society, a series of environmental pollution problems emerge One of the most concerned problems is the water pollution caused by antibiotics For example, tetracycline (TC), a typical antibiotic, is widely used in medicine and feed additives because it can treat bacterial diseases, ranking second in the production and use of antibiotics However, only a small part of tetracycline will be absorbed and metabolized by human or animals, and the rest will exist in the environment as excrement or itself, which will pose a serious threat to the ecosystem Therefore, it is urgent to remove the excess tetracycline and protect the environment The results show that the semiconductor catalyst can degrade tetracycline completely by solar energy without secondary pollution and can be used for a long time Therefore, the key to solve the environmental problems caused by tetracycline pollution is to find efficient semiconductor catalyst γ - in 2SE 3 nanomaterials have good optical absorption properties of visible and ultraviolet light, but there are few researches on its photocatalytic degradation of water pollution In addition, because the driving force of crystal growth process comes from the reduction of total surface energy, under natural conditions, crystal tends to grow along the direction of high-energy crystal surface to reduce its surface energy, resulting in low content of high-energy crystal surface, while high-energy crystal surface usually has high photocatalytic activity Therefore, we can adjust the atomic structure of the surface of the photocatalyst by adjusting the crystal surface of the semiconductor materials and exposing the specific crystal surface of the crystal to increase the photocatalytic activity of the nano materials, and further enhance and optimize the photocatalytic performance, which has attracted the attention of researchers With the aid of EDTA (ethylene diamine etraacetic acid), the research group synthesized the tetragonal prismatic γ - in2se 3 with the main exposed {110} crystal surface, as shown in Figure 1 EDTA is a bridge complex in water When it is added into the reaction system, it will ionize rapidly into anion and anion In the process of aggregation of in 2SE 3 nanoparticles and growth along the high energy crystal surface, the anion COO - formed by EDTA ionization in solution can combine with in 3 + to form complex The outermost atom of γ - in 2SE 3 {110} crystal surface is in 3 +, and EDTA can be adsorbed on {110} crystal surface When the amount of EDTA is sufficient, it can effectively inhibit the crystal growth along {110} surface The crystal surface is exposed Figure 1: TEM and HRTEM of γ - in2se 3 prepared by adding EDTA of different concentrations: (a) (edta-0.00 m), (b) (edta-0.02 m), (c) (edta-0.04m), (d) (edta-0.06 m), (E) single γ - in2se 3 (edta-0.04 m) and (F) applied catalyst B: Environmental The photocatalytic degradation TC performance of nano materials was tested, as shown in Figure 2 The results show that the main exposure of 0.04 m EDTA to {110} γ - in 2SE 3 has the best photocatalytic performance, about 1.9 times of that of the cone-shaped γ - in 2SE 3 without EDTA This is because there are a large number of active sites on the {110} surface of γ - in2se 3 mainly exposed, which makes the separation of photogenerated electron hole pairs easier, thus enhancing the photocatalytic activity The results reveal a new method to control the crystal surface of γ - in2se 3 {110} Fig 2: (a) mechanism of photocatalytic degradation of TC by γ - in2se 3, (b) photocatalytic degradation rate curve of TC, (c) corresponding pseudo first-order reaction kinetics curve (source: applied catalyst B: environmental)