Converting CO2 with various epoxides to cyclic carbonates is extremely important. However, most of catalysts for such conversion either require complicated fabrication or are obtained from unsustainable sources. Motivated by this problem, we prepare biomass-based “all-in-one” carbon dots as nano-organocatalysts for firstly converting CO2 to cyclic carbonates. In this work, carbon dots (CD@KI) with high catalytic performance and good recyclability are prepared from sodium phytate (SP), polyethylenimine (PEI) and KI using one-pot hydrothermal treatment featuring cheap precursors and simple operation. Assisted by highly catalytic activity of CD@KI, up to 99.5% yield is achieved for converting CO2 and various epoxides to cyclic carbonates under mild conditions (solvent-free and 1 atm of CO2). Moreover, the conversion yield is maintained for reactions up to ten grams in scale. Significantly, by taking advantage of the inherent luminescence of CD@KI, the as-formed cyclic carbonates catalyzed by CD@KI can be directly converted to afterglow polymer composites.

Photothermal devices and thermoelectric cells hold great promise for energy generation but integration of the two remains a considerable challenge in real-life power supply for sensors. Here, a novel photo-thermo-electric hydrogel (PTEH-Interlocking) was constructed by synthesis of a photothermal layer on a thermoelectric hydrogel with the redox pair Fe(CN)63−/Fe(CN)64−. The smart design of using oxidation of pyrogallic acid by Fe(CN)63− to construct the photothermal layer for photo-to-heat conversion protected the redox couple of the thermogalvanic ion pair from ultraviolet damage, as well as triggered the formation of an interlocking structure at the interface of the photothermal layer and the thermoelectric hydrogel. The as-prepared PTEH-Interlocking have shown a high Seebeck coefficient and rapid heat transfer, boosting the photo-thermo-electric conversion. As a demonstration of a practical application, the PTEH-Interlocking cells is successfully used as the energy supply for a mechanical sensor.