Antibacterial Evaporator Based on Wood-Reduced Graphene Oxide/Titanium Oxide Nanocomposite for Long-Term and Highly Efficient Solar-Driven Wastewater Treatment

Herein, we developed antifouling and highly efficient solar absorbers consisting of poplar wood coated with titanium dioxide (TiO2) and reduced graphene oxide (RGO) nanocomposites (with different weight ratio of TiO2 to RGO). The antibacterial activity of all prepared nanocomposites against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was investigated. The results showed that T2G1 (a nanocomposite in which the weight ratio of TiO2 to RGO is 2:1) has the highest antibacterial activity among all nanocomposites (MIC of 0.08 and 0.08 mg mL–1 and MBC of 0.6 and 0.8 mg mL–1 for E. coli and S. aureus, respectively). Therefore, it was considered to be the most efficient photothermal material for interfacial solar desalination and solar-driven treatment of wastewater. Because of the broad-band solar absorption by T2G1, the solar absorber composed of T2G1 and wood (denoted as T2G1-w) showed a high energy conversion efficiency of 90.12% under 1 sun (1 kW m–2). T2G1-w also had a high stability for long-term cycles. T2G1-w also showed great performance of freshwater production from contaminated water containing dye or heavy metals. The concentration of heavy metals of Zn2+, Pb2+, Fe2+, Ni2+, and Cr6+ reduced from 1000 mg L–1 to near zero in the presence of the prepared solar absorber, indicating its great potential application for sewage treatment

Interfacial solar steam generation by wood-based devices to produce drinking water: a review

International audienceFreshwater supply is declining in the context of climate change, pollution, and soil salinization, calling for sustainable methods to produce drinking water. For instance, salt water can be converted into pure water by steam generation. Interfacial solar steam generation involves photoabsorbers consisting of a photothermal material with broad solar absorption and a porous substrate with a thermal insulating character. Nonetheless, scaling up of classical devices for interfacial solar steam generation is actually limited by cost, biofilm formation, salt fouling, complicated fabrication processes, and toxicity. Alternatively, wood-based devices are cheap, biodegradable, abundant, and display high fluxes of evaporation compared with other non-biodegradable photoabsorbers. Here we review the design and applications of wood-based solar steam generation devices, with focus on wood structure and properties, different types of devices, and factors controlling the evaporative performance