Highly efficient and sustainable wood-based plasmonic photoabsorber for interfacial solar steam generation of seawater

In this study, we present a highly efficient and sustainable photoabsorber designed specifically for interfacial solar steam generation (ISSG) of seawater. To achieve this, we coated poplar wood with Ag-doped VO₂ (Ag@VO₂) and reduced graphene oxide (RGO) as single or double layers of photothermal materials. The evaporation flux of Ag@VO₂ coated on poplar wood is 2.42 kg m⁻² h⁻¹, while RGO-coated poplar wood exhibited a slightly lower evaporation flux of 2.38 kg m⁻² h⁻¹. However, the evaporation flux significantly improved to 3.85 kg m⁻² h⁻¹ when poplar wood was coated with a combination of Ag@VO₂ and RGO, with Ag@VO₂ serving as the bottom layer and RGO as the top layer. The remarkable enhancement in ISSG performance observed in the double-layer photoabsorber (RGO/Ag@VO₂/wood) is attributed to several synergistic effects. Firstly, the combination of Ag@VO₂ and RGO facilitates efficient harvesting of visible and near-infrared light, enabling effective energy conversion in the ISSG process. Additionally, the surface plasmonic resonance effect exhibited by Ag further enhances light absorption. Furthermore, the low thermal conductivity and porous structure of wood, acting as a substrate, contribute to improved photoabsorber performance. Another crucial finding from our study is the stable performance exhibited by the fabricated photoabsorber. Even after undergoing 10 cycles of operation, there was no decrease in efficiency. This stability is of significant importance for practical applications, as it ensures consistent and reliable performance over time.