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

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 mu S 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.

Automated summary

A cost-effective, scalable, and highly efficient water-treatment material was prepared by coating an iron/nickel-reduced graphene oxide nanocomposite on poplar wood, which achieved significant reduction in salinity, pH, and electrical conductivity of seawater. The material also showed promising performance in solar steam generation and heavy metal sorption, making it a viable option for water treatment applications.