The outcome of the photochemical reaction also depends on the presence of other organic solvents or water in the medium. The use of acetonitrile as solvent significantly suppressed H2O2 production and possibly also benzaldehyde formation (Table ), which is in line with previous reports that found that the quenching of the excited state of benzaldehyde and the corresponding hydrogen abstraction process are conditioned by the type of the solvent. Moreover, a control experiment carried out by irradiating benzyl alcohol-benzaldehyde mixture under monophasic water-free and solvent-free conditions showed that even a higher amount of H2O2 was produced, while no increase of the benzaldehyde concentration was observed after 24 h (Table , black curves in Figure ).