More Accurate Method for Evaluating the Activity of Photocatalytic Hydrogen Evolution and Its Reaction Kinetics Equation

Photocatalytic water splitting to hydrogen is a sustainable energy conversion method. However, there is a lack of sufficiently accurate measurement methods for an apparent quantum yield (AQY) and a relative hydrogen production rate (rH2) at the moment. Thus, a more scientific and reliable evaluation method is highly required to allow the quantitative comparison of photocatalytic activity. Herein, a simplified kinetic model of photocatalytic hydrogen evolution was established, the corresponding photocatalytic kinetic equation was deduced, and a more accurate calculation method is proposed for the AQY and the maximum hydrogen production rate vH2,max. At the same time, new physical quantities, absorption coefficient kL and specific activity SA, were proposed to sensitively characterize the catalytic activity. The scientificity and practicality of the proposed model and the physical quantities were systematically verified from the theoretical and experimental levels.