Assessment of activity of ‘transparent and clear’ and ‘opaque and highly coloured’ photocatalytic samples using a fluorescent photocatalytic activity indicator ink, FPaii

Mills, Andrew; Yusufu, Dilidaer; Wells, Nathan; O’Rourke, Christopher

doi:10.1016/j.jphotochem.2016.07.019

Cited by 8 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The paii technology outlined above is well suited for assessing photocatalytic materials in the laboratory and, recently, has been used to assess (i) highly colored materials (through the significant fluorescence exhibited by Rf, see S3 in the Supporting Information), 30 (ii) powdered UV and visible-light absorbing photocatalysts, 31 and (iii) photocatalytic materials in situ, i.e., indoors and outdoors, using a mobile phone to record the digital images. 32 In situ testing of photocatalytic films would be better served if the indicator was in the form of a label and recent work suggests that a reusable paii label can be made by combining MB and glycerol with the pressure sensitive adhesive polymer, poly(vinyl alcohol), PVA.…”

Section: A Mb Reusable Paii Labelmentioning

confidence: 99%

Section: A Mb Reusable Paii Labelmentioning

confidence: 99%

See 1 more Smart Citation

Photocatalyst Activity Indicator Inks, paiis, for Assessing Self-Cleaning Films

2021

Self Cite

View full text Add to dashboard Cite

Conspectus Semiconductor photocatalysis, usually referred to simply as “photocatalysis” is a relatively new and yet still a growing subject area, which has led to a billion-dollar industry, mostly focused on the production of self-cleaning architectural materials, such as glass, paint, tiles, fabric, plastic and concrete. All such materials need to be tested for activity, but for self-cleaning activity there are few appropriate tests; the International Standards Organization, ISO, for example, have at present only two, both of which are slow and largely ineffective for most commercial self-cleaning products. The photocatalyst community in general, and the manufacturers of self-cleaning photocatalytic products in particular, need a fast, simple, easy to use method of assessing photocatalytic activity, which can also be used to demonstrate the efficacy of self-cleaning materials in minutes, i.e., a quantitative and qualitative test. In this account we highlight our work on photocatalyst activity indicator inks, i.e., paiis, which address the above need and work via the photocatalyzed reduction of a dye, usually resazurin, Rz, and concomitant oxidation of an organic, almost always glycerol. We describe our early work on the Rz ink which showed that, when used to assess photocatalytic film activity, the measured rate of change in color is directly proportional to the measured rate of photocatalyzed mineralization of the popular test pollutants stearic acid, SA, and methylene blue, MB, by O2. We show that photography, coupled with digital color analysis, is just as effective and much less expensive at measuring the rate of color change exhibited by paiis as UV/vis spectrophotometry and also can be used for testing clear and opaque photocatalytic samples in the laboratory and in situ. We demonstrate how the Rz ink can be used to assess the activities of both UV and Visible light absorbing photocatalytic powders and thin films, and highly colored samples. The kinetics of the photocatalyzed color change are outlined, which are zero-order with respect to the initial dye concentration and ink film thickness. We describe the basic features of the recently published Rz-ink based ISO for the qualitative and quantitative assessment of activity of nonporous, flat photocatalytic films. Although the Rz ink is best suited for assessing films of moderate photocatalytic activity, such as found in most examples of commercial self-cleaning glass, other paiis are described which can be used to assess commercial products that have much higher or lower, activities, such as photocatalytic paints and tiles, respectively. Examples of how paiis have been used in research over recent years are given, a highlight of which is their use in the search for a suitable, visible light absorbing photocatalyst alternative to TiO2, that can compete with the latter in terms of cost, durability, stability, and activity. Finally, the novel, photocatalyst-based inks that have been developed as a consequence of the works on paiis are discussed briefly, inclu...

show abstract

Section: A Mb Reusable Paii Labelmentioning

confidence: 99%

Section: A Mb Reusable Paii Labelmentioning

confidence: 99%