Nature-inspired poly(N-phenylglycine)/wood solar evaporation system for high-efficiency desalination and water purification

The development of low-cost, scalable wood-based photothermal systems that utilize renewable solar energy for energy conservation and desalination has received extensive attention. Although some materials such as precious metals, semiconductor materials and carbon nanomaterials have been used as light absorbers, the issues of low evaporation rate and efficiency, as well as the high energy consumption and cost of photothermal layer design need to be addressed. In this work, inspired by the transpiration process of trees, a poly(N-phenylglycine) (PNPG)-wood solar evaporator was developed. The coating of PNPG, a conjugated polymer with good light absorption, greatly cover the shortage of weak light absorbance of wood, and effectively improved the solar-heat conversion efficiency. Moreover, benefited from the low thermal conductivity and special microstructure of the wood, the relationship among water transport, solar energy conversion, and heat regulation was better adjusted. As a result, the PNPG-wood system can effectively and quickly generate steam, the evaporation rate and efficiency can be 1.64 kg m–2 h–1 and 90.4% under 1 sun, which are higher than most reported wood-based solar evaporators. Hence, such a well-designed, cost-effective, durable, and high-efficiency solar evaporation system has the potential to be applied to solve the practical problem of seawater desalination and water purification.