Clean water production by non-noble metal/reduced graphene oxide nanocomposite coated on wood: Scalable interfacial solar steam generation and heavy metal sorption

Abstract Herein, a cost-effective, bifunctional, scalable, and highly efficient water-treatment material was prepared by coating iron/nickle (Fe/Ni)-reduced graphene oxide (RGO) nanocomposite on poplar wood which was used both as non-noble metal based photoabsorber in interfacial solar steam generation of seawater and as highly efficient heavy metal sorbent. The solar evaporation fluxes of 1.43 and 4.19 kg m−2h−1 under 1 and 3 sun (1 sun = 1 kW m−2), respectively were achieved by the most efficient photoabsorber (RGO200/FeNi-wood). The evaporation efficiency of the photoabsorber did not change significantly even after 20 cycles. After desalination by RGO200/FeNi-wood, a remarkable reduction in the salinity (4 order of magnitude), pH (8.1 to 6.2), and electrical conductivity (6000 to 2.25 µS cm−1) was achieved. The cost per produced steam rate was calculated as 0.03 $ cm−3h under 3 sun which is comparable to the best double-layer devices reported in the literature. RGO200/FeNi-wood could act as a novel sorbent to remove Pb (II) completely from aqueous solutions.