Study On The Preparation And Application Of Novel Photocatalytic Materials

In recent years, photocatalytic technology has been paid much attention for its potential contribution in the area of environmental pollution control and energy utilization.Based on the above research background, the main work of this thesis is focused on two aspects:(1) exploring the new synthetic route for porous ZnO nanomaterials, the photocatalytic activity of as-prepared porous ZnO nanomaterials was studied;(2) modification of TiO2 to improve its photocatalytic performance, the effects of synthesis method and reaction condition on photocatalytic activity of as-prepared N-doped Ti O2 and ZnTiO3/TiO2 materials were systematically studied. Subsequently, the photodegradation process and mechanism of the as-prepared N-doped TiO2 and ZnTiO3/TiO2 materials for organic targets unver simulated sunlight and visible light irradiation were analyzed in detail. Some meaningful conclusions and valuable achievements have been obtained, which provided theoretical and experimental basis for successfully realizing degradation of organic pollutants by efficiently utilizing solar energy. This thesis contains the following major parts:(1) In this work, porous ZnO nanomaterials were successfully synthesized via the mixed solvo-thermal method. The as-prepared ZnO nanomaterials were characterized by XRD and TEM to analyze the composition, morphology and structure. Based on the experimental result, the growth mechanism was preliminarily discussed. RhB was used as the organic target to evaluate the photocatalytic performance of ZnO under UV irradiation. The photocatalytic experiment results revealed that porous ZnO nanomaterials showed good degradation efficiency for RhB, which could completely degrade 10 mg/L RhB within 50 min and exhibited better photocatalytic performance than that of P25, the reason was mainly ascribed to the porous structure of ZnO. In the experimental process, the hydrothermal route for synthesis of porous ZnO is a new liquid phase synthetic method, which provides a new prospective for synthesis of other metal oxides with porous structure. The as-prepared porous ZnO showed good photocatalytic performance under UV irradiation, which could offer a new effective route to degrade many toxic and harmful pollutants in the environment.(2) The photocatalytic decoloration of furfural wastewater using N-doped TiO2 materials under simulated light irradiation was studied. The as-prepared N-doped TiO2 materials were characterized by XRD, SEM and DRS to analyze the composition, morphology and structure. Based on the experimental result, the photocatlytic decoloration mechanism was preliminarily discussed. Furfural wastewater was used as the organic target to evaluate the photocatalytic performance of N-doped TiO2 materials under simulated light irradiation. The photocatalytic decoloration experiment results revealed that the optimum photocatalytic decoloration efficiency under simulated irradiation was obtained when the N molar fraction, furfural wastewater concentration, and concentration of N1 in furfural wastewater were 15.7%, 0.020 mL/mL, and 0.05 mg/L, respectively. The decoloration results exhibited that the furfural wastewater decoloration efficiency was 97.35% with 12 h under simulated light irradiation, which could provide a new route for highly efficient treatment furfural wastewater and have a very good practical prospect. Compared with traditional furfural wastewater treatment process, TiO2 photocatalytic technology could make urfural wastewater treatment to meet the wastewater discharge standard and also greatly improve economic benefit. TiO2 photocatalytic technology, as a new type of wastewater control technology, has achieved great theoretical and experimental results in the current study of industrial wastewater treatment. Researchers should constantly carry out researches to improve the TiO2 photocatalytic technology, which will make make TiO2 photocatalytic technology fully applied to industrial wastewater treatment field.(3) The preparation, characterization and photocatalytic performance of large-sized ZnTiO3/TiO2 composites using for spraying field have been studied. The as-prepared ZnTiO3/TiO2 composites were characterized by XRD and SEM to analyze the composition, morphology and structure. Based on the experimental result, the photocatlytic mechanism was preliminarily discussed. RhB was used as the organic target to evaluate the photocatalytic performance of ZnTiO3/TiO2 composites under visible light irradiation. The photocatalytic experiment results revealed that the optimum photocatalytic efficiency under visible light irradiation was obtained when the ZnTiO3 molar fraction, calcination temperature and time, ZnTiO3/TiO2 composite dosage were 2%, 600 oC and 2 h, 1.0 g/L, respectively. The photocatalytic results exhibited that the photocatalytic efficiency was 97.24% with 5 h under visible light irradiation, which provided a new route for highly efficient treatment of printing and dyeing wastewater and showed a very good practical prospect. In addition to the photocatalysis application, owing to their big size, density and strength, ZnTiO3/TiO2 composites can be applied in the spray field.