Thermal-assisted UV digestion utilizing nano-TiO2 photocatalyst for the detection of total phosphorous

This work presents a novel thermal-assisted ultra-violet (UV) photocatalysis oxidation method for total phosphorus (TP) detection. A 365nm wavelength UV light was used as the UV light source, and the TiO2 particles, immobilized on silicon wafer, were used as the catalyst. The sodium glycerophosphate was digested as the typical compound of TP. The digested samples were determined by spectrophotometry after the phosphomolybdenum blue reaction. The catalyst can be used repetitively with long-term stability in this work. For the photocatalysis digestion process under room-temperature, when the reaction time reached 120min, the conversion rates were 92.31% and 93.66% for lmg/L and 4mg/L of C3H7Na2O6P solutions, respectively. And conversion rates were 95.48% and 99.37% respectively for thermal-assisted ultra-violet (UV) photocatalysis digestion process at the condition of 30min and 60 degrees C. Compared with the conventional thermal digestion method and photocatalysis digestion method for TP detection, this thermal-assisted UV digestion method can greatly decrease the digestion time and enhance the efficiency.