Simple Design of a Porous Solar Evaporator for Salt-Free Desalination and Rapid Evaporation

Solar-driven interfacial evaporation is considered to be one of the promising and efficient ways of producing clean water in recent years. However, it remains a challenge to develop solar evaporation devices with high solar evaporation rates and salt-free blocking properties. Here, a porous solar evaporator with directed water transport and salt-free desalination through excellent photothermal conversion and purposefully guided migration of the salt solution was developed. The designed porous photothermal sponge with the synergistic effect of MXene and polypyrrole can achieve evaporation rates of 1.47 and 2.27 kg m–2 h–1, respectively, in the capillary model and siphon model water-transporting solar evaporation devices. More interestingly, the designed zigzag-shaped device with an evaporation rate of 2.45 kg m–2 h–1 was achieved. In addition, the evaporator can operate stably under 9 h in the siphon model solar evaporation device and achieves the effect of salt-free desalination. The above design provides a good strategy for solar-powered desalination applications.