The measurements are represented as yield of gas (H2 or CO) per weight of the substrate (µmol gsub -1 ) and activity per weight of the photocatalyst per hour (µmol gcat -1 h -1 ). For the experiments with the integrated system, the H2 evolution data is represented in terms of the aerial efficiency of the photocatalyst panel, (µmol mirr -2 ). Unless otherwise indicated, the analytical measurements were performed in triplicates and represented as the unweighted mean ± standard deviation.