A scalable broadband plasmonic cuprous telluride nanowire-based hybrid photothermal membrane for efficient solar vapor generation

Solar vapor generation utilizes ubiquitous solar energy to address the issue of global water shortage. However, its large-scale field deployment is greatly hampered by inefficient solar absorption, moderate evaporation efficiency and high cost. Here, we report a new hybrid photothermal membrane, named broadband plasmonic Cu2−xTe nanowire (bpCu2−xTe) membrane, for interfacial solar evaporation to produce freshwater from various water sources. The bpCu2−xTe membrane features excellent broadband solar absorption (~95.9%), high porosity and hydrophilicity, and low thermal conductivity (0.55 W/(m K)), which enables a water evaporation rate as high as 4.3 kg/(m2 h) with the evaporation efficiency of up to 96% under 3 kW/m2 solar irradiation. The evaporation performance of the present Cu2−xTe membrane can be maintained even after it recycles multiple times under various solar irradiance, indicating excellent durability and stability. Efficient solar desalination of seawater is further demonstrated with the bpCu2−xTe membrane to deliver drinkable water. The combination of scalable fabrication ability, low cost and excellent solar evaporation performance of the bpCu2−xTe membrane highlights the potential for seawater purification and desalination in field applications.