A Photothermal/Catalytic Integrated Solar Evaporator for Stable Purification of High‐Concentration Dye Sewage

Abstract

Solar evaporators have demonstrated huge potential in sewage purification and clean water supply based on their cost‐effective and sustainable merits. However, it remains challenging to realize the stable purification of high‐concentration dye sewage over the long term. Here, by incorporating a heterojunction photocatalyst, a photothermal/catalytic integrated solar evaporator is conceived to stabilize the purification of high‐concentration dye sewage. It is composed of g‐C3N4@TiO2 heterojunction as the photocatalyst, carbon nanotubes (CNTs) as the photothermal materials, and polyvinyl alcohol (PVA) network as water transportation material. The high photocatalytic activity of heterojunction enables the g‐C3N4@TiO2/CNTs/PVA (CTCP) evaporator to photodegrade the accumulated dye molecules on its evaporation surface under light irradiation during purifying dye sewage. More remarkably, the integrated CTCP evaporator achieves a stable evaporation rate of 2.30 kg m−2 h−1 in 1 mg mL−1 RhB solution with continuous light irradiation for 100 h, exhibiting preeminent long‐term stability. With the capacities of long‐term stable and high‐rate purification of high‐concentration dye sewage, it is expected that this CTCP evaporator provides an effective alternative to treat high‐concentration dye sewage and has direct implications in engineering multifunctional solar evaporators for complex wastewater treatment.