- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
UV and visible-light driven photocatalytic removal of caffeine using ZnO modified with different noble metals (Pt, Ag and Au)
摘要： In this work, ZnO photocatalyst was modified with different noble metals (Pt, Ag and Au) through photo-deposition method and then characterized by different techniques (XRD, XRF, BET, UV–vis DRS, FESEM, and XPS). The addition of noble metals produces important changes in the light absorption properties with a significant absorbance in the visible region due to the existence of surface plasmon resonance (SPR) observed at about 450 nm and 550 nm for ZnO modified with Ag and Au, respectively. The morphology of the samples was studied by TEM and the size ranges of the different metals were estimated. Noble metal nanoparticles were in every case heterogeneously deposited on the larger ZnO particles. All the prepared photocatalysts were tested in the photocatalytic removal of caffeine (toxic and persistent emerging compound) under UV and visible light irradiation. It was observed an enhancement of photocatalytic caffeine removal from aqueous solutions under UV light irradiation with the increase of metal content (from 0.5 to 1 wt %) for ZnO modified with Ag and Au (Ag/ZnO and Au/ZnO). In particular, Ag/ZnO and Au/ZnO with higher Ag and Au content (1 wt %) allowed to achieve the almost complete caffeine degradation after only 30 min and a TOC removal higher than 90% after 4 h of UV light irradiation. These two photocatalysts were investigated also under visible light irradiation and it was found that their photocatalytic performances were strongly enhanced in presence of visible light compared to unmodified ZnO. In particular, Ag/ZnO photocatalyst was able to reach the complete caffeine degradation and a TOC removal of about 70% after 4 h of visible light irradiation.
关键词： Caffeine removal,Photocatalysis,ZnO,UV and visible light,Noble metals
更新于2025-09-23 15:23:52
-
Fusion algorithm of infrared and visible images based on frame difference detection technology and area feature
摘要： A kind of fusion algorithm of infrared and visible images based on frame difference detection technology and area feature was proposed to increase the fusion quality of the infrared image and reduce complexity. Firstly, frame difference method was designed to complete detection on objectives in infrared images so as to conduct objective clustering and image segmentation; information among frames is used to complete accurate locating of objective; then different fusion rules were designed to complement effective information of visible light and infrared images as possible and complete image fusion according to features of objective area. The complexity of fusion algorithm in this thesis was analyzed theoretically. Meanwhile, fusion experiment was executed on two conditions of unmovable and observable objective in image of visible light and infrared light and movable and observable objective in image of visible light and infrared light; experiment result indicates that proposed technology has higher fusion quality and the fusion image can accurately reflect objective and background compared with current image fusion technology.
关键词： area feature,Image fusion,objective area segmentation,frame difference detection,infrared and visible light image
更新于2025-09-10 09:29:36
-
Preparation of activated carbon nanotube foams loaded with Ag-doped TiO2 for highly efficient photocatalytic degradation under UV and visible light
摘要： Titanium oxide (TiO2) has been widely investigated as a photocatalytic material for degradation of organic pollutant in waste water. However, nanosized granular TiO2 nanoparticles are hard to be recycled and re-utilized in water and many cause secondary pollution of water. Hence, we constructed a foam-like photocatalyst, which was composed of carbonaceous support: activated carbon nanotube foams and Ag-doped TiO2 nanoparticles through a method of a template synthesis and carbonization strategy. The as-prepared photocatalyst evidenced to be hierarchical macroporous and mesoporous and exhibited remarkable photocatalytic performance toward the degradation of unsymmetrical dimethylhydrazine under UV and visible light. The structure characterization and photocatalytic performance investigation confirmed that the enhanced photoresponse was attributed to the high efficiency of charge separation and the surface plasmon resonance effect of metallic Ag. The adsorption synergetic effect of the hierarchical porous structure also played an important role in photodegradation. The as-prepared photocatalyst showed great potential in the treatment of waste water containing organic pollutant.
关键词： Ag-doped TiO2,Photocatalytic degradation,Activated carbon nanotube foams,Unsymmetrical dimethylhydrazine,UV and visible light
更新于2025-09-10 09:29:36