Reduced graphene oxide/silver/wood as a salt-resistant photoabsorber in solar steam generation and a strong antibacterial agent

Abstract

Interfacial solar steam generation (SSG) of seawater opens a novel scene to address water shortage and stress. In this work, reduced graphene oxide (RGO) and silver nanoparticles (NPs) were prepared, coated on poplar wood, and used as a single and double-layer photoabsorbers in SSG of seawater. The maximum evaporation rate per unit area of 5.99 kg m−2 s−1 and four orders of magnitude reduction in salinity were achieved under 3 sun (1 sun = kW m−2) for the optimum double-layer photoabsorber due to the synergistic effect of surface plasmon resonance phenomenon of Ag NPs and black color and the conjugated aromatic rings of RGO. The evaporation efficiency of the optimum photoabsorber did not change even after 11 cycles. The cost per produced steam rate was calculated as 0.011 $ cm−3 h. The antibacterial activity of the bare wood and the optimum double-layer photoabsorber against methicillin-resistant Staphylococcus aureus (MRSA) was also investigated in dark. The optimized photoabsorber had strong antibacterial activity so that the bacterial growth was totally inhibited during 24 h whereas it increased with time for bare wood.