In thermal liquid-phase catalysis the problems associated with the separation of metastable products are often solved by the use of biphasic systems comprising two immiscible solvents and thus enabling the separation of the catalyst and the product right after the formation of the latter. Such an approach, though highly relevant for photocatalytic production of valuable chemicals, has been very rarely used in the field of photocatalysis so far, mainly due to the lack of photocatalysts suitable for operation under biphasic conditions. To this end, Yamashita et al. recently devised a hydrophobic Ti-based MOF for the biphasic selective benzyl alcohol oxidation to benzaldehyde in the organic phase (benzyl alcohol) and dioxygen reduction to H2O2, which was continuously extracted into the aqueous layer. However, we have recently demonstrated that benzaldehyde formed under such reaction conditions acts itself as a visible light-active photocatalyst that drives the (auto)photocatalytic H2O2 production and makes the assessment of true performance of the photocatalyst highly unreliable. An unambiguous demonstration of effective photocatalytic H2O2 production in a biphasic system therefore i) requires the design of efficient hydrophobic photocatalysts, and ii) makes the use of electron donors different from benzyl alcohol absolutely mandatory.