A Power-Law Relationship between Characteristics of Light Source and Quantum Yield in Photocatalytic Systems

A new dimensionless parameter, Sh-factor, is introduced by using dimensional analysis and extending the quantum yield definition to show power-law relations among light intensity, light wavelength, distance from light source, concentrations of dye/pollutant and photocatalyst, time, and degradation percent. The Sh-factor has the same equation form for photoactivated remediation systems with particulate and thin-film photocatalysts, and it provides mathematical tools to predict degradation performance of a photocatalytic system. These power-law equations separate simply the operational parameters related to the lamp from semiconductor photocatalyst characteristics. The light scattering and absorption were also considered in Sh-factor as extended quantum yield. It was concluded that the Sh-factor could be used to model the photocatalytic system with various operational parameters. This extended quantum yield allows us to organize photocatalytic systems with thin-film photocatalysts apart from particulate pho...