Stretchable photothermal membrane of NIR-II charge-transfer cocrystal for wearable solar thermoelectric power generation.

Harvesting sunlight into cost-effective electricity presents an enticing prospect for self-powered wearable applications. The photothermal materials with an extensive absorption are fundamental to achieve optical and thermal concentration of the sunlight for efficiency output electricity of wearable solar thermoelectric generators (STEGs). Here, we synthesize an organic charge-transfer (CT) cocrystal with a flat absorption from ultraviolet to second near-infrared region (200 to 1950 nanometers) and a high photothermal conversion efficiency (PCE) of 80.5%, which is introduced into polyurethane toward large-area nanofiber membrane by electrospinning technology. These corresponding membranes demonstrate a high PCE of 73.7% under the strain more than 80%. Sandwiched with carbon nanotube-based thermoelectric fibers, the membranes as stretchable solar absorbers of STEGs could supply a notably increase temperature gradient, processing a maximum output voltage density of 23.4 volts per square meter at 1:00 p.m. under sunlight. This strategy presents an important insight in heat management for wearable STEGs with a desired electricity output.

Regenerated Silk Nanofibers for Robust and Cyclic Adsorption-Desorption on Anionic Dyes.

In recent years, adsorption-based membranes have been widely investigated to remove and separate textile pollutants. However, cyclic adsorption-desorption to reuse a single adsorbent and clear scientific evidence for the adsorption-desorption mechanism remains challenging. Herein, silk nanofibers were used to assess the adsorption potential for the typical anionic dyes from an aqueous medium, and they show great potential toward the removal of acid dyes from the aqueous solution with an adsorption rate of ∼98% in a 1 min interaction. Further, we measured the filtration proficiency of a silk nanofiber membrane in order to propose a continuous mechanism for the removal of acid blue dye, and a complete rejection was observed with a maximum permeability rate of ∼360 ± 5 L·m-2·h-1. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy studies demonstrate that this fast adsorption occurs due to multiple interactions between the dye molecule and the adsorbent substrate. The as-prepared material also shows remarkable results in desorption. A 50-time cycle exhibits complete adsorption and desorption ability, which not only facilitates high removal aptitude but also produces less solid waste than other conventional adsorbents. Additionally, fluorescent 2-bromo-2-methyl-propionic acid (abbreviated as EtOxPY)-silk nanofibers can facilitate to illustrate a clear adsorption and desorption mechanism. Therefore, the above-prescribed results make electrospun silk nanofibers a suitable choice for removing anionic dyes in real-time applications.