The sample is digested with a mixed acid mixture of a certain proportion of concentrated nitric acid, concentrated sulfuric acid, and concentrated perchloric acid. In a weakly acidic medium (acidity 0.05mol/L ~ 0.20mol/L), silicon and molybdate form yellow silicon molybdenum. Heteropolyacids. In the presence of tartaric acid, it is reduced to silicon molybdenum blue by a reducing agent, and its absorbance is measured at a wavelength of 815 nm with a spectrophotometer.
T/CGIA 013-2019 history
2019T/CGIA 013-2019 Determination of silicon content in graphene materials — Molybdenum blue spectrophotometry