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Adsorption and Photocatalytic Decomposition of Gaseous 2-Propanol Using TiO2-Coated Porous Glass Fiber Cloth
摘要： Combinations of TiO2 photocatalysts and various adsorbents have been extensively investigated for eliminating volatile organic compounds (VOCs) at low concentrations. Herein, TiO2 and porous glass cloth composites were prepared by acid leaching and subsequent TiO2 dip-coating of the electrically applied glass (E-glass) cloth, and its adsorption and photocatalytic ability were investigated. Acid leaching increased the specific surface area of the E-glass cloth from 1 to 430 m2/g while maintaining sufficient mechanical strength for supporting TiO2. Further, the specific surface area remained large (290 m2/g) after TiO2 coating. In the photocatalytic decomposition of gaseous 2-propanol, the TiO2-coated porous glass cloth exhibited higher adsorption and photocatalytic decomposition ability than those exhibited by the TiO2-coated, non-porous glass cloth. The porous composite limited desorption of acetone, which is a decomposition intermediate of 2-propanol, until 2-propanol was completely decomposed to CO2. The CO2 generation rate was affected by the temperature condition (15 or 35 °C) and the water content (2 or 18 mg/L); the latter also influenced 2-propanol adsorption in photocatalytic decomposition. Both the conditions may change the diffusion and adsorption behavior of 2-propanol in the porous composite. As demonstrated by its high adsorption and photocatalytic ability, the composite (TiO2 and porous glass cloth) effectively eliminates VOCs, while decreasing the emission of harmful intermediates.
关键词： air purification,composite,adsorption,microporous material,porous glass,photocatalyst,TiO2
更新于2025-11-19 16:51:07
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A brief survey of the practicality of using photocatalysis to purify the ambient air (indoors or outdoors) or air effluents
摘要： This survey attempts to evaluate the possibilities of using heterogeneous photocatalysis to purify air in the three title domains. Regarding indoor air, the formation of degradation intermediate products, some of which can be toxic or irritating, is the key issue for obvious safety reasons. Accordingly, commercializing individual purifiers is questionable because their management cannot securely be left to the user’s responsibility. When the purifier is incorporated in air ducts, adequate control can possibly be achieved permanently via proper sensors automatically adjusting the air flow to always deliver healthy air; also, if the pressure drop enables it, an adsorbing filter before air admission in the occupied spaces could be added. The main issue would then be the cost, which depends on the photocatalyst efficacy and its gradual decrease essentially due to solid deposits (including SiOx formed from Si-containing compounds present in the air). Regarding outdoor air, the rates are inherently low because of the scanty percentage of UV radiation in sunlight. Above all, because of the obvious need for the pollutants to be transferred to the photocatalytic surfaces, a potential significant effect of photocatalysis will be limited to rare confined spaces. Additionally, the deposition of dirt and photocatalytically-formed inorganic salts - which can accumulate in rain-sheltered locations - will further decrease over time the already low efficacy. Hence, the interest of photocatalytic materials for purifying outdoor air seems moot, despite some claims. Regarding air effluents, the practicality of the photocatalytic treatment obviously depends on the effluent contents in pollutants and water vapor, the volume to be treated, and the requested quality of the treated air. If, after trials, the treatment is thought to be economically viable for the targeted effluent, the industrial environment will enable the necessary monitoring. Nevertheless, research aiming at improving the reactor design, the photocatalyst activity and lifetime, and, possibly, the sunlight use, can be needed for competing more efficiently with well-established processes on a case-by-case basis.
关键词： Photocatalysis. Indoor air. Outdoor air. Air effluents. Air purification
更新于2025-09-23 15:23:52
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Handbook of Ecomaterials || Environmental Photocatalysis/Photocatalytic Decontamination
摘要： Water pollution caused by hazardous substances has become a global concern. Textile and dyestuff industries produce large amounts of wastewater containing various dye pollutants. Most azo dyes are nonbiodegradable and their release into the environment poses a major threat to the surrounding ecosystems. Remediation of organic aquatic pollutants by photocatalytic oxidation has proven to be an attractive promising technology among the advanced oxidation processes. Semiconductor photocatalysis is a topic of current interest mainly in view of its potential application in the mineralization of pollutants.
关键词： Pilot scale treatment,Heterogeneous photocatalysis,Air purification,Antimicrobial activity,Semiconductor oxides,Water pollution
更新于2025-09-23 15:21:21
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Hydrophilic surface modification of TiO2 to produce a highly sustainable photocatalyst for outdoor air purification
摘要： Recently, TiO2 photocatalysts have been applied in various ways for outdoor air purification. The main challenge with these applications is the stability of the photocatalysts, as the surface of TiO2 can be easily deactivated by contaminants found in outdoor environments. For example, it is difficult to remove oily contaminants with water once they are exposed to the photocatalyst surface since the hydrophilicity of TiO2 is not sufficiently high to allow for self-cleaning. In the present work, we modified the surface of commercial TiO2 nanoparticles to be more hydrophilic; this was done by coating them with a thin polydimethylsiloxane (PDMS) layer and applying a subsequent heat treatment under vacuum. The surface-modified TiO2 showed outstanding ability to repel oily contaminants deposited on its surface upon exposure to water droplets due to its superhydrophilic properties. Then, we evaluated the UV-light-driven photocatalytic activity of the surface-modified TiO2 for the decomposition of acetaldehyde. The surface-modified TiO2 showed photocatalytic activity for the decomposition of acetaldehyde that was comparable to that of bare TiO2. We show that our hydrophilic-surface-modified TiO2 has high potential for applications in outdoor air purification for an extended time period.
关键词： Air purification,Acetaldehyde,Photocatalysis,TiO2,Superhydrophilicity
更新于2025-09-19 17:15:36
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Comprehensive Membrane Science and Engineering || 3.5 Photocatalytic Processes in Membrane Reactors
摘要： Photocatalytic membrane reactors (PMRs) represent an interesting alternative technology useful both in the field of water and air purification and in organic syntheses. The necessity to develop chemical products and industrial processes that reduce or eliminate the use and the generation of toxic substances along with the risk for human health and for environment constitutes the aim of the research efforts based on the principles of green chemistry.
关键词： air purification,green chemistry,Photocatalytic membrane reactors,water purification,organic syntheses
更新于2025-09-04 15:30:14
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Synthesis of Cu-Doped Ti-Containing MCM-41 and its Photocatalytic Performance for Indoor Air Purification
摘要： The prepared catalysts were synthesized in a mild way and characterized by various analytical instruments including X-ray diffraction, nitrogen physisorption, UV-visible spectroscopy, high resolution-transmission electron microscopy and X-ray photoelectron spectroscopy. All samples exhibited the typical mesoporous structure and spherical structure. Copper and titanium species in the MCM-41 support were well anchored on the mesoporous framework in the form of metal oxides. The adsorption tests for formaldehyde examined the positive effect of metal incorporation. In the static state test, MCM-41 adsorbed 31 % of formaldehyde and Ti/Cu-MCM-41 elevated this value to 41 %. Moreover, Ti/Cu-MCM-41 demonstrated the superior photocatalytic performance under both UV- and visible-light irradiation, achiveing 57 % and 18 % of formaldehyde degradation at the end of reaction, respectively. With the X-ray photoelectron spectroscopy and UV-Visible results, an intense interaction between Ti and Cu was observed and the synergy effect mechanism in the bimetallic catalyst was proposed.
关键词： MCM-41,Cu-Doped Ti,Air purification,Photocatalyst
更新于2025-09-04 15:30:14