Stepwise irradiative engineering based on Einstein quantum theory for promoting PVA/TiO2 photocatalytic activity at minimized irradiance consumption

Promoting photocatalytic performance by modulating the external irradiation field is a new concept in both photocatalytic theory and applications. Here, based on the Einstein rate equation, we have firstly demonstrated that the duration of atom activity can be prolonged by decoupling the weak excitation towards ultra-violet spectra or saturating the irradiative intensity at material central frequency. Guided by the theoretical deduction, the wavelength dispersive in-situ florescence spectroscopy and stepwise irradiative technique were then employed to give experimental evidences, where the theory derived optimal irradiation field was validated for promoting photocatalytic activity of Polyvinyl Alcohol (PVA)/TiO(2 )hybrid materials. By periodically projecting the optimal excitation instead of continuous visible illumination, the photocatalytic performance can be improved by 15% with nearly halved irradiance consumption (55%). It is believed that these findings might push photocatalytic efficiency into higher steps with the assistance of a deep understanding of irradiative theory and engineering.