Open top containers with an irradiation area of 1.5 cm  1.5 cm were designed in SolidWorks and fabricated using an Ultimaker 2 Extended+ 3D printer for the water evaporation experiments (Supplementary Fig. ). The containers were filled with H2O and the floating photocatalyst sheets were placed on the liquid surface. The samples were irradiated by a solar light simulator (G2V Sunbrick LED Solar Simulator)