To meet the escalating global demand for water resources in arid regions, fog harvesting presents a promising solution especially in high-humidity regions. However, current collectors generally suffer from critical issues such as low droplet capture efficiency, difficulty in droplet retention and transportation, and poor cyclic stability. Inspired by the water-capturing abilities of bat tongues and cactus spines, a fog harvester with a folding fan structure and a spike array has been developed. These hierarchically structured surfaces, fabricated by laser etching, control wettability to capture and drive the unidirectional transport of water droplets. The spikes further allowed for the regulation of droplets to achieve transport along a Janus wettability gradient. Compared to a conventional flat aluminum sheet of the equivalent projected area, this device achieved a 403.58 % higher collection efficiency. It also exhibited remarkable cyclic stability, long-term water performance, and corrosion resistance, thereby demonstrating its potential for practical applications. This work provides an efficient strategy for sustainable fog collection.
Qian Zhao,Guangqiang Liu,Hongwen Zhang,Weiping Cai
A simple and cost-effective route to fabricating gold-coated glass nano-stings' arrays is presented for highly efficient surface enhanced Raman spectroscopy (SERS) chips via reactive ion etching of the glass slide covered with polystyrene (PS) colloidal monolayer and sputtering deposition of gold on it. The as-fabricated SERS chips consist of the nearly-hemispherical particles with submicron-size, which are hexagonally arranged into the ordered arrays. There are many short and long Au-coated glass nano-stings standing vertically on the hemispherical particles, showing high density tips (up to 7.0 × 103 μm−2). The formation of such gold-coated glass hierarchically structured array is attributed to the geometry of PS colloidal monolayer and the nanoscale roughness of glass slide's surface. Further, it has been demonstrated that such gold-coated glass array chip is highly SERS-active and can be utilized to detect trace organophosphorous toxicant with the limit below ppt level and good reproducibility in measurements. The intensity of the Raman peak shows the linear relation, in logarithmic scale, with the organophosphorous concentration from ppt to ppm level, exhibiting the possibility of quantitative detection in a large concentration range. This work has demonstrated the cost-effective method to fabricate the high performance SERS chips for trace detection of toxic molecules.
危险品化学品经营许可证（带存储）