Are you still using organic dyes? Colorimetric formaldehyde analysis for true photocatalytic-activity evaluation.

We report easily available and highly reliable colorimetric formaldehyde analysis using only a spectrophotometer/colorimeter, which enables the evaluation of the "true" photocatalytic activity induced by photoabsorption of a "photocatalyst", compared with gas-chromatographic analyses of gaseous products, even though the reliability of colorimetric organic-dye analysis is much worse under visible-light irradiation.