Chemical Scissors Tailored Nano-Tellurium with High-Entropy Morphology for Efficient Foam-Hydrogel-Based Solar Photothermal Evaporators

Abstract

The development of tellurium (Te)-based semiconductor nanomaterials for efficient light-to-heat conversion may offer an effective means of harvesting sunlight to address global energy concerns. However, the nanosized Te (nano-Te) materials reported to date suffer from a series of drawbacks, including limited light absorption and a lack of surface structures. Herein, we report the preparation of nano-Te by electrochemical exfoliation using an electrolyzable room-temperature ionic liquid. Anions, cations, and their corresponding electrolytic products acting as chemical scissors can precisely intercalate and functionalize bulk Te. The resulting nano-Te has high morphological entropy, rich surface functional groups, and broad light absorption. We also constructed foam hydrogels based on poly (vinyl alcohol)/nano-Te, which achieved an evaporation rate and energy efficiency of 4.11 kg m−2 h−1 and 128%, respectively, under 1 sun irradiation. Furthermore, the evaporation rate was maintained in the range 2.5–3.0 kg m−2 h−1 outdoors under 0.5–1.0 sun, providing highly efficient evaporation under low light conditions. [Figure not available: see fulltext.]