Electrochemically prepared coniferous leaf-like nickel black membrane for desalination by solar-thermal energy conversion

The structures of the solar-thermal membranes always influence the performance of light absorption and salt resistance in desalination. Inspired by the hierarchical structure of the coniferous leaves with excellent sunlight absorption in frigid regions, a coniferous leaf-like nickel black (L-Ni) membrane for desalination by solar-thermal energy conversion was prepared through electroplating method under a constant voltage. The light trapping effect of coniferous leaf-like structure led to the light absorption enhanced to 92%, the evaporation rate improved to 1.38 kg·m⁻²·h⁻¹, and the solar-vapor conversion efficiency of L-Ni membrane reaching up to 89.75% under 1 sun irradiation. The stability of the membrane was still excellent after 20 cycles desalination because the coniferous leaf-like structure could enhance the hydrophobicity (water contact angle: 152°) of the L-Ni membrane, and it was beneficial to salt resistance. The promising performance of L-Ni membrane with coniferous leaf-like structure provides a possibility to replace the noble metal solar-thermal conversion materials.