Polyethersulfone-silica aerogel/ polypyrrole solar evaporation membrane for wastewater treatment and desalination

Abstract

Solar interfacial evaporation utilizes a specific structure of the evaporator to confine the energy to the light absorbing layer, so that the water completes efficient evaporation on the surface of the structure. In this paper, polyethersulfone- silica aerogel/ polypyrrole solar evaporation membranes (PES-SiO2/PPy) with excellent photo-thermal conversion and efficient seawater desalination performance were prepared by loading PPy on polyethersulfone-silica aerogel ultrafiltration membranes (PES-SiO2) via in situ polymerization. With its stable and efficient thermal insulation performance and heat absorption ability, the temperature on the surface of the evaporation membrane was as high as 49.9 °C under 1 kW m−2 light intensity, and the maximum evaporation rate reached 1.86 kg m−2 h−1, with an evaporation efficiency of 97%. The evaporation membranes also have long-term stable evaporation performance. At an outdoor light intensity of 0.8 kW m−2, the evaporation rate of simulated seawater reached 1.87 kg m−2 h−1 with a high evaporation efficiency of 131.6%, which can be realized for highly efficient desalination and dye-containing wastewater treatment with the aid of ambient energy. The present work demonstrates the efficient solar evaporation performance of ultra-low-cost evaporation membranes with the prospect of large-scale water purification treatment.