A low-cost plant transpiration inspired 3D popsicle design for highly efficient solar desalination

Solar-powered desalination is an attractive solution to the problem of water scarcity, but the practical applications of three-dimensional (3D) interfacial solar steam generators have been limited by their complex production methods, low water generation rates, and durability issues. This study proposes a low-cost, easy-to-produce 3D solar steam generator with a popsicle design that employs diesel soot coated on polyvinyl alcohol sponges and plant transpiration-inspired chopsticks wrapped in airlaid paper for efficient water transport. The effects of various design factors are investigated, and it is found that the DSp-PVA-3D-6 configuration achieved an impressive evaporation rate of 3.81 kg m−2 h−1 under one sun illumination. The generator also demonstrated anti-salt fouling ability and sustained high evaporation performance over an extended period. Indoor seawater desalination studies yielded positive outcomes, while outdoor experiments showed that the DSp-PVA-3D array efficiently produced fresh water (2 L m−2 h−1) meeting daily human fresh water requirements. This proposed design is a significant step towards creating practical, inexpensive steam generators for real-world solar-powered saltwater desalination, offering a promising solution to global water scarcity.