Multifunctional Photoabsorber for Highly Efficient Interfacial Solar Steam Generation and Wastewater Treatment

Abstract Interfacial solar steam generation (ISSG) is a sustainable and environmental‐friendly technology for seawater desalination and wastewater purification using green and sustainable solar energy. Herein, a robust and efficient interfacial solar steam generation device or photoabsorber for ISSG of seawater and wastewater treatment was designed by coating wood with trace amount of Pd nanoparticles (NPs) and reduced graphene oxide (RGO). High evaporation flux of 5.25 kg m −2 h −1 was achieved by Pd20/RGO80/wood (a piece of wood was coated with 80 and 20 mg L −1 of Pd NPs and RGO as a top and bottom layer, respectively) under 3 kW m −2 . The value of electrical conductivity of seawater decreased from 6000.0 to 5.8 μS cm −1 after desalination. The durability test showed the photoabsorber was stable for 30 cycles. The total cost to evaporation rate of the device was calculated as 0.29 0.003 USD/(cm 3 h −1 ). The photoabsorber also showed excellent performance in wastewater treatment in removal of dyes of methylene blue and Reactive blue 5. Also, the concentration of heavy metals of Zn 2+ , Cd 2+ , Pb 2+ , Fe 2+ , Ni 2+ , and Cr 6+ reduced from 1000 ppm to near zero in the presence of photoabsorber.