A Renewable and Antibacterial Solar Evaporator for Efficient Seawater Desalination: Performance Analysis and Empirical Formula

Interfacial solar evaporation has been considered as a compromising way to alleviate water shortage. However, when applied in real sea water environment, the undissolved salt accumulation and bacteria adhesion will cause blockage and fouling problem of the evaporator, and deteriorate its evaporation performance. Herein, a solar evaporator based on hollow cylinder-shaped photocatalytic modified ceramic with renewability and antibacterial activity is fabricated for efficient seawater desalination. This evaporator can reach an evaporation rate of 3.43 kg m⁻² h⁻¹ in the normal environment (1 sun irradiation, 50% ambient relative humidity and 0 m s⁻¹ convective airflow) and also can reach a rate of 28.9 kg m⁻² h⁻¹ in the controlled environment (1 sun irradiation, 10% ambient relative humidity and 5 m s⁻¹ convective airflow) due to the sufficient effective evaporation area and timely vapor diffusion. Meanwhile, after long-term desalination of real seawater, the blocked evaporators can be regenerated by acid treatment. The evaporator also shows 91.7% antibacterial ratio due to photocatalytic modification. In the field environment, the array evaporator shows a good evaporation performance of 54.5 kg m⁻² for continuous 10 h. Finally, the empirical formula is obtained to quantitatively analyze the environmental factors and predict the evaporation rate in practical application.