Synthesis Of Low-band Gap Metal Oxides Photocatalyst And The Study On Their Degradation Of Antibiotic In Water

Water pollution as a primary issue of environmental pollution attracts most attention.With the continuous development of medical industry, various kinds of antibodies have beenwidely found in different aquatic environments. After released into the environment,antibiotics will affect aquatic organisms and induce bacterial resistance.Also, it is difficult totreat antibodies due to its high toxicity and complicated composition. At the same time thenegative impact of antibiotics residue in water pose the risk to the health of human.Therefore, more and more attented have been paid to this serious issue. The treated methodsof waste water mainly included physics methods, chemical methods, biochemical methods, etal. Unfortunately, the conventional physical and chemical treatments are always high cost orhave seconded pollution which lack of enough efficiency for antibodies removal.Photocatalytic oxidation technology, as one of the AOPs (Advanced Oxidation Processes),is most likely to take advantage of natural sunlight for decontamination environmentallyfriendly, which may be an ideally method to realize removal of pollutant. Among thephotocatalytic material, oxide photocatalyst, as one friendly materials, have attracted mostattention for environmental protection and energy saving due to its low price, none pollutionto environment and resistance light corrosion. However, oxide photocatalyst has limitation forpractical application, such as low photons efficiency and lack of selectivity. Thus, to developstrong respond to visible light irradiation, high photocatalytic activity and low-band gapphotocatalysts becomes a research hotspot.Herein, we prepared and modified oxide photocatalyst to improve the photocatalyticefficiency of photocatalyst and responsiveness of visible light.The work mainly included the following items:(1) Hydrothermal synthesis of WO3nanosheets photocatalyst and the study onphotocatalytic performancea. In our work, we have successfully synthesized WO3nanosheets via a hydrothermalmethod under the condition of low temperature preparation and conducted photocatalyticdegradation test with Rhodamine B and tetracycline waste water solution. The results showedthat WO3nanosheets in visible light had catalytic activity.b. Pt decorated WO3nanosheets favors electron transfer process to improve the separationof electrons and holes effectively. Significant enhancement of activity has been clearly foundon Pt/WO3nanosheets compared with WO3nanosheets. The photocatalytic mechanism ofPt/WO3are studied at the same time, and the active species captured test indicated the·OH radicals do exist in the process of the photocatalytic oxidation (PCO) ofTC.(2) The synthesis and application research of indium trioxide of two differentmorphologies photocatalystBy microwave hydrothermal method and solution heat method indium trioxide cube andmicrospheres are synthesized respectively. The photodegradation performance analysisshowed that indium trioxide cube and microspheres has properties to photodegrade TC undervisible light.(3) Rapid microwave-assisted synthesis of Bi2O3tubes and photocatalytic properties forantibioticsa. Bismuth oxide (Bi2O3) nanotubes have been successfully synthesised via a rapidmicrowave-assisted synthetic method for the first time. Moreover, the photocatalyticproperties of Bi2O3in the degeneration of antibiotics, especially tetracycline (TC) andciprofloxacin (CIP), were studied. Our research showed that the prepared Bi2O3sample at lowtemperatures has a strong absorbency and has a perfect photocatalytical activity under visiblelight.b. We study the time-dependent degradation of TC and CIP by the same amount of Bi2O3under the same photocatalytic degeneration condition. The photocatalytic degeneration rate of10mg/L TC and20mg/L TC is83.63%and61.04%, respectively，and that of20mg/L CIPis only34.90%. We have found that it has better photocatalytic effect in the degeneration ofTC compared with CIP which means that Bi2O3has certain selectivity in the photocatalyticdegradation process of antibiotics.(4) Solvent thermal synthesis and photocatalytic degradation of waste water ofInxBi(2-x)O3microspherea. InxBi(2-x)O3microspheres were synthesized by solvothermal solution, The method issimple, economical, without adding a surfactant template. Through the preparation byappropriate changes in reaction parameters and conditions to investigate the optimalformation conditions of solid solution InxBi(2-x)O3microspheres.b. InxBi2-xO3microspheres showed high photodegradation rate of tetracycline undervisible light. Significant enhancement of activity has been clearly found on InxBi2-xO3microspheres compared with In2O3and Bi2O3. The photocatalytic mechanism of InxBi2-xO3isstudied at the same time, and the active species captured test indicated the holes do exist inthe process of the photocatalytic oxidation (PCO) of TC. (5)Titanium dioxide macroporous materials doped with iron: synthesis andphoto-catalytic propertiesFe/Ti-M (1%,5%,10%, and50%) with a3D macroporous structure has beensuccessfully synthesized. Tuning the doping quantity of Fe can significantly affect the crystalstructure of the resulting Fe/Ti-M. The obtained samples exhibited the Fe3Ti3O10phase whenthe quantity of Fe was equal to Ti. Moreover, the Fe/Ti-M showed a significant red shift inresponse to the doping of Fe. The photo-catalytic properties of Fe–Ti–Oxide-M were studiedunder visible light in-depth. Taking into account the crystal structure and absorption spectra,the Fe/Ti-M (10%) showed the optimal catalytic activity among the samples with differentdoping quantities of Fe in this system.