Determination of the real quantum yield of the heterogeneous photocatalytic H2 production reaction and insights

Determination of the real quantum yield (QY) of a heterogeneous photocatalytic H-2 production reaction is crucial and challenging. Here, we constructed a setup enabling the exact measurement of the number of incident photons received by photo-vessel, and the directly absorbed part by photocatalysts, thus achieving simultaneous determination of QY and apparent quantum yield (AQY). It turns out that over the whole investigated wavelength region, the value of AQY is significantly smaller than that of QY. For instance, the AQY and QY of Cd0.5Zn0.5S were measured as 40% and 70% at 420 nm, respectively. We have demonstrated that a lot of incident photons are scattered by the photocatalyst particles and dissipated, instead of being absorbed and converted. It indicates that the true photocatalytic performance of a photocatalyst could have been severely underestimated in the past by AQY in previous studies. Therefore, our work should be valuable for accurate catalytic efficiency evaluation of a photocatalyst, and contributes to the rapid development of the technology.

Automated summary

The study established a setup to accurately measure the number of incident photons received by a photo-vessel and directly absorbed by photocatalysts, enabling simultaneous determination of QY and AQY. It was found that AQY was significantly smaller than QY, indicating that the true photocatalytic performance of the photocatalyst may have been underestimated in previous studies. This work is valuable for accurate evaluation of catalytic efficiency of a photocatalyst and contributes to the rapid development of the technology.