Degradation of Gaseous Formaldehyde by Visible Light-Responsive Titania Photocatalyst Filter

Abstract

A method is proposed that uses electrophoretic deposition (EPD) to fabricate the titania (TiO2) photocatalyst filter and then successfully modifies it by lithium nitrate (LiNO3) to be visible light responsive such that the modified photocatalyst filter effectively degrades gaseous formaldehyde. The performance of degrading gaseous formaldehyde is evaluated in the photocatalytic circulation reactor for different temperature and light sources. The results show that the modified TiO2photocatalyst filter has much better degradation performance for gaseous formaldehyde than the original TiO2photocatalyst filter regardless of light source, and the performance is better at the higher ambient temperature. The best total average degradation performance of the modified photocatalyst filter is about 9.2% and 16.3% higher than the original photocatalyst filter (P-25, Degussa) for the UVA and visible irradiation, respectively, at 26°C.

Biodegradable tough waterborne hyperbranched polyester/carbon dot nanocomposite: approach towards an eco-friendly material

“…This homogenization of all the components facilitates to strong interactions and thus increased the rate of cross-linking reaction. 10,31,41,42 The different curing times are required for curing of PCD0, PCD0.1, PCD0.5 and PCD1 to achieve nearly the same extent of curing as indicated by the swelling values (20-25 %) of the resultant thermosets ( Table 1). The curing time is the time required to attain the desired swelling value (20-25%) of the thermosets.…”

“…This is in turn decreases the entanglement density and intra-and intermolecular interactions within the polymer chains. [38][39][40][41] With the increase of loading of CD, both the values of G′ and G″ increase due to the same reasons.…”

“…Due to these cross-links, different ions or species present in different media cannot easily penetrate the surface and thereby increases the chemical resistance of the nanocomposite. 21,41 3.8 Biodegradation study Polyesters, owing to the presence of hydrolysable ester bonds in their polymeric chains, are prone to microbial attack. 10,21 The thermosets of nanocomposite were directly exposed to Gram negative and Gram positive bacterial strains.…”

“…As the loading of CD increases, the rate of ester bond hydrolysis also increases, which results in a higher rate of biodegradation. 21,41 Among all the thermosets of WHP/CD nanocomposite, PCD1 showed the highest rate of biodegradation as it contains the highest content of CD. The representative SEM micrographs PCD0.5, PCD1, pristine and control (film without bacterial medium) after four weeks of bacterial exposure further support the biodegradation abilities of the nanocomposites, images are shown in Fig.…”