Indoor and outdoor monitoring of photocatalytic activity using a mobile phone app. and a photocatalytic activity indicator ink (paii)

• Resazurin based ink used to assess the activity of commercial self-cleaning films.
• Mobile phone camera and colour monitoring app. used to record digital images of ink.
• Direct correlation between red colour change in an image and absorbance change of ink.

A resazurin (Rz) based photocatalyst activity indicator ink (paii) is used to test the activity of commercial self-cleaning materials. The semiconductor photocatalyst driven colour change of the ink is monitored indoors and outside using a simple mobile phone application that measures the RGB colour components of the digital image of the paii-covered, irradiated sample in real time. The results correlate directly with those generated using a traditional, lab-bound method of analysis (UV–vis spectrophotometry).

The semiconductor photocatalysed reduction of dye in an activity indicator ink is monitored using a mobile phone in combination with a colour monitoring application, allowing the outdoor assessment of the activity of commercial photocatalyst based self-cleaning films.Figure optionsDownload as PowerPoint slide