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

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-C 3 N 4 @TiO 2 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-C 3 N 4 @TiO 2 /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.