BS ISO 10678:2010 pdf free download Fine ceramics (advanced ceramics, advanced technical ceramics) — Determination of photocatalytic activity of surfaces in an aqueous medium by degradation of methylene blue
This International Standard specifies a method for the determination of the photocatalytic activity of surfacesby degradation of the dye molecule methylene blue(MB) in aqueous solution using artificial ultraviolet (Uv)radiation,and characterizes the ability of photoactive surfaces to degrade dissolved organic molecules onultraviolet radiation.
The test method specified is also applicable to evaluation of the specific photocatalytic self-cleaning activity ofsurfaces covered with respective coatings.
This method is not applicable to characterizing the photoactivity of surfaces on visible illumination, regardingdirect soiling,degradation of gaseous molecules and the determination of antimicrobial photoactivity ofsurfaces.
NOTE Correlations between these different kinds of photocatalytic activity can, however,exist,in particular atsurfaces exhibiting low photonic efficiencies.
Terms and definitions
For the purposes of this document, the following terms and definitions apply.2.1
specific photocatalytic activityPMB
measure of the photochemical conversion
NOTESpecific photocatalytic activity is expressed in moles per square metre and hour [mo(m3m)J.
2.2
photonic efficiency
6 Calibration
The apparatus according to 5.5 and 5.6, as well as the balances used, shall be calibrated following theinstructions for equipment monitoring.
7 Measuring and conditioning solution
Aqueous methylene blue solutions shall be used for both the measurement and the conditioning. Themethylene blue solutions shall be prepared freshly from stock solutions stored in the dark using distilled waterin the absence of any other additives. The initial MB concentration co for the test solution shall be=(10±0.5) umol/L. The conditioning solution shall be prepared at a concentration of c =(20± 1) umolL.The absorbance,AA , of the solutions shall be calculated using Equation (1):