Abstract Utilizing solar steam generation to treat seawater and sewage, as an emerging and effective technology, can obtain clean water. There is an abundance of water demand and a shortage of water supply in the world today. Herein, we demonstrate an integrated evaporator of boron nanosheets modified with molybdenum disulfide (MoS2) as a photothermal materials and a konjac glucomannan (KGM) sponge with excellent pore structure as a thermal insulator and water supplier for solar clean water generation. A rapid evaporation rate (1.538 kg m−2 h-1) and high solar evaporation efficiency (96.5 %) under 1-sun radiation (1 kW m−2) can be achieved in the two-dimensional structure system. This work provides a new way to design and manufacture renewable solar steam generation for water purification.