A novel 3D solar evaporator constructed based on the principle of interface evaporation and its application in oil removal and environmental control

[Display omitted] •A sodium alginate hydrogel was successfully grown on the aerogel surface.•The designed solar steam device had the self-floating characteristic.•Bismuth molybdate was introduced into the floating layer to degrade dyes. It is a challenge to construct devices for producing clean and purified water. In this paper, devices assembled using an aerogel-hydrogel composite and a floating layer were used to produce clean water while purifying water sources. A low-surface-tension polymer and bismuth molybdate were loaded to the surface of a carrier through co-deposition. The contact angle of the constructed superhydrophobic fabric, canvas and felt was 162°, 159° and 160° respectively. Even under the external force of deformation, the beads still quickly left the surface, showing a low adhesion effect. The purification efficiency of the assembled self-floating solar steam generator was 99.82 % and 99.48 % for rhodamine B (Rh B) and methyl orange (MO) respectively, whose mechanical stability and salt suppression capacity were demonstrated through stress–strain curves and photothermal experiments with a high saline concentration (10 wt% NaCl). Through the introduction of bismuth molybdate in the floating layer, not only the roughness increased, but the properties of photodegradation performance were also achieved. Through an active substrate capture test and a band structure analysis, the h+ played a decisive role in the degradation process. The valence and conduction band position of the catalyst were 2.28 eV and −0.35 eV, respectively.