关键词: Au@Cu2O, 光热转换, 光催化, 双功能织物, 界面蒸发

Abstract: The scarcity of fresh water resources has become a major threat to human survival and development. It is critical to maintain social stability and development by addressing the scarcity of fresh water resources. Solar-driven interfacial evaporation technology can use solar energy directly to purify wastewater and produce clean water without relying on fossil fuels. It has received widespread attention due to its low cost, sustainability, and environmental friendliness. However, when solar steam is generated during the purification process, non-volatile impurities may remain and accumulate, causing more serious pollution. Pollutants can be effectively degraded by incorporating a photocatalytic system. The bifunctional fabric was combined with the photo-thermal photocatalytic bifunctional cuprous oxide (Cu2O)-based heterojunction material in this paper to produce clean water.
At the moment, research on the production of clean water via interfacial evaporation is focused on how to improve the evaporation rate and the water transport rate. There hasn't been much research into how to remove pollutants while evaporating water. The majority of related research focuses solely on stacking two distinct materials, photothermal and photocatalytic, on the same substrate to achieve dual functions. Because it can be excited by visible light, Cu2O is widely used in photocatalysis. Nevertheless, photo-corrosion affects the photoactivity of Cu2O, limiting its exclusive use. To improve its photocatalytic activity, Cu2O is usually combined with metal. Au is a precious metal that is frequently used to improve the catalytic activity of Cu2O, but its photothermal properties are rarely used. The Au@Cu2O heterostructure was created in the experiment by using gold rods (Au NRs) with near infrared absorption as the core. The thickness of the Cu2O shell was changed by adjusting the Au/Cu ratio, resulting in a successful Au@Cu2O near infrared response. A bifunctional material with photothermal and photocatalytic properties was designed and prepared successfully, and its application in water purification was investigated by combining it with cotton fabrics. Under the irradiation of a simulated solar source with a power density of 0.1 W/cm2, the evaporation rate of the Au@Cu2O-modified cotton fabric is 1.25 kg/(m2·h), the conversion efficiency of sunlight to steam is 77.4%. After 180 minutes of visible light irradiation, the degradation rate of methyl orange reaches 89.2%.
Water scarcity has sparked widespread concern as a global issue. Using solar-driven interfacial evaporation to produce clean water not only corresponds to the current state of water scarcity, but also makes use of solar energy, an inexhaustible source of energy. Photothermal photocatalytic bifunctional materials can decompose pollutants in water while allowing for water evaporation, which is a gap in current research but has significant application potential.

Key words: Au@Cu2O, photothermal conversion, photocatalysis, bifunctional fabric, interfacial evaporation