High-efficiency wood-based evaporators for solar-driven interfacial evaporation

Wood has shown great application potential in the field of solar-driven interfacial evaporation owing to its low cost and unique physical properties. However, most of the previously reported wood-based evaporators exhibit relatively low evaporation efficiency. In this work, we experimentally study the evaporation performance of carbonized balsawood evaporators (CBWs), carbonized basswood evaporators (CBSWs), and carbonized pinewood evaporators (CPWs) under different carbonization degrees. With the increase of the carbonization degree, the solar absorption and the thermal conductivity of the CBWs, CBSWs, and CPWs present different variation regularity, which causes them to provide the optimal evaporation performance at different carbonization degrees, and it is shown that the optimal evaporation performance is not always achieved at the highest solar absorption. The CBW-20 %, CBSW-15 %, and CPW-10 % exhibit the best evaporation performance, with the evaporation rate of 2.13 kg·m−2·h−1, 2.067 kg·m−2·h−1, and 1.979 kg·m−2·h−1 under 1 Sun, respectively, and the corresponding evaporation efficiency of 90.56 %, 88.79 %, and 90.42 %, respectively. Moreover, CBW-20 %, CBSW-15 %, and CPW-10 % all show good salt resistance in simulated seawater, indicating that the evaporation performance of the wood-based evaporators can be significantly improved by coordinating the solar absorption and the thermal conductivity. These efficient and low-cost solar-driven evaporators with simple and controllable fabrication can have practical application prospects in desalination.