This could be avoided by hydrophobically treating the reactor window via silanization to improve the formation and flow of water down the window. Under natural sunlight, a consistent STH of 0.08±0.01% was achieved, while the H2 evolution and clean water production rate dropped to 7.82±1.52 mmol m -2 h -1 and 0.71±0.12 kg m -2 h -1 , respectively. The decline in the overall products formed for the outdoor experiments was likely due to the lower incident light intensity over the course of the outdoor experiments (avg.~0.6 sun, see Supplementary Fig. ). Our techno-economic analysis revealed that the proposed hybrid photothermal-photocatalyst sheets have potential economic advantages over an existing photocatalyst panel where the cost of water purification and land use are more expensive in a real-world scenario (Supplementary Table , Supplementary Discussion 4).