Turning waste into treasure: Utilizing discarded printer toner-modified wood for efficient solar water evaporation in diverse water environments

The interfacial solar steam generation (ISSG) technology has garnered significant attention as a promising pathway for sustainable and environmentally friendly clean water production. However, it is crucial but still challenging to develop photothermal materials with wide sources, low costs, and simple preparation methods. This study introduces the concept of using waste printer toner as a photothermal material to modify the upper surface of renewable wood and construct an ISSG system. The toner evaporation interface demonstrates full-spectrum solar absorption characteristics and excellent photothermal conversion capability. By adjusting the loading amount of toner on the evaporation interface, a water evaporation rate of 1.79 kg·m−2·h−1 can be achieved under optimal conditions, along with a solar evaporation efficiency of up to 94.1 %. Due to the typical Janus structure formed by the hydrophobic properties of the toner evaporation interface, the constructed ISSG system demonstrates tolerance to high-salinity water, as well as long service life and stability in evaporation performance. When faced with various water conditions (such as actual seawater, dye water, and acidic/alkaline water), the reported ISSG system also exhibits satisfactory water purification effects. This study underscores the immense potential of discarded toner in the realm of photothermal materials, providing a fresh perspective for cost-effective photothermal solutions in interfacial water evaporation systems.