A novel strategy to extend near-infrared light harvest of graphene for solar vapor generation and high-efficiency oil-water separation

Due to the feature of zero bandgap, graphene has presented a rapid and broadband photothermal responsibility. However, the near-infrared light absorption of graphene is relatively low, which is unfavourable for the full utilization of solar energy. Therefore, in our work, flower-like MoS2 nanostructure was used to promote the optical absorption of graphene. Further, combining with the porous skeleton of sugarcane residues and the simplified hydrophobic treatment method, a novel water treatment material (GNS@MoS2-SR) is successfully prepared. Recently, solar-assisted oily water treatment and solar steam generation were widely proposed to relieve the shortage of clean water. In the absorption test, it is confirmed that GNS@MoS2-SR can absorb 8.02-16.8 g/g oils from oil-water mixture and presents high stability during recycle. Moreover, the great hydrophobicity and photothermal conversion effect helps GNS@MoS2-SR to evaporate similar to 1.778 kg/m(2) water in 1 h, under one solar illumination (1 kW/m(2)). Besides, the optimized hydrophobicity of GNS@MoS2-SR effectively suppressed the salt precipitation and prevented the decline of spectrum absorption. The multifunctional water treatment material we designed integrates the respective advantages of graphene and MoS2, presents a significant potential in relieving water stress.

Automated summary

In this study, a novel water treatment material (GNS@MoS2-SR) was designed, which utilizes flower-like MoS2 nanostructure to enhance the light absorption of graphene, combined with the porous skeleton of sugarcane residues and simplified hydrophobic treatment method. The experimental results demonstrate that GNS@MoS2-SR can efficiently absorb oil from oil-water mixture and maintain stability during recycling. Additionally, its hydrophobicity and photothermal conversion effect enable it to evaporate water efficiently under solar illumination.