Hybrid organic–inorganic perovskite (HOIP) ferroelectrics with high Curie temperature ( T c ), typified by the lead halide hybrid perovskite ferroelectrics, are developing rapidly owing to their maneuverable ferroelectricity at high temperatures. However, acquiring high- T c lead-free HOIP ferroelectrics via rational strategy still needs development. In this study, a brand-new program by modulating the steric confinement in a cuplike cavity to design high- T c bismuth-halide ferroelectrics [H 2 mdap]BiX 5 (H 2 mdap = N -Methyl-1,3-Propanediamine, X = Cl ( 1 ), Br ( 2 ), I( 3 )) is proposed. Emphatically, the T c enhanced dramatically from 264 K of 3 to 318 K of 2 and 377 K of 1 , induced by the substitution of Br and Cl to I, accompanied with an interesting transition from second-order phase transition (for 3 ) to the first-order one (for 1 and 2 ). The extent of T c increase is up to 113 K, which far outweighs that of reported Pb-halide hybrid ferroelectrics. Structural and computational analyses elucidate that this unprecedented improvement of T c is due to the higher phase transition energy barriers induced by modulating the steric confinement of cuplike cavity via halogen substitution. These results will provide new inspiration for designing high- T c lead-free HOIP ferroelectrics.
Azo-based photoswitchable molecules can undergo configurational transformations by tuning the wavelength of incident light, thereby enabling efficient energy storage. Polymer-based solid–solid phase change materials are capable of storing and releasing thermal energy through surroundings temperature regulation without experiencing macroscopic morphological changes. There is growing interest in constructing hybrid systems that enable synergistic collection and release of energy in thermal management systems. Herein, a series of meta -azopyridine compounds with electron-donating and electron-withdrawing groups are synthesized, the azopyridine derivative with the highest energy density can reach up to 312 J g −1 . Meanwhile, polyethylene glycol is employed as the phase change component to synthesize solid–solid phase change polyurethanes featuring robust mechanical properties and favorable shape stability. Most importantly, a flexible energy-storage device is innovatively integrated employs the above-mentioned two systems, capable of coharvesting photon and phase change energy reaching up to 388 J g −1 . The temperature regulation capability of the devices through the storage and release of photothermal and phase change energy is demonstrated as a thermal-insulation material, showing potential application in external thermal-insulation aspects for transport pipelines.
A large of energy consumption is required for indoor and outdoor personal heating to ameliorate the comfortable and healthy conditions. Main personal thermal management strategy is to reflect mid-infrared human body radiation for human surface temperature ( T HS ) regulation. We demonstrate a visible Janus light absorbent/reflective air-layer fabric (Janus A/R fabric) that can passively reflect radiative heating meanwhile can actively capture the solar energy. A series of azobenzene derivatives functionalized with alkyl tails are reported to co-harvest the solar and phase-change energy. The T HS covered by Janus A/R fabric can be heated up to ~ 3.7 °C higher than that covered by air-layer fabric in cold environment (5 °C). Besides, integrating the thermo- and photo-chromic properties is capable of monitoring comfort T HS and residue energy storage enthalpy, respectively. According to the colour monitors, intermittent irradiation approach is proposed to prolong comfortable- T HS holding time for managing energy efficiently. Graphical Abstract For the personal thermal management, we fabricate a visible Janus light absorbent/reflective fabric, which can actively capture solar energy and passively reflect the human radiation reflection (MIR). The solar energy can be released as heat to actively warm human surface temperature up, and the reflective MIR can passively heat the human body. The surface temperature and residue energy storage can be monitored by distinct colour change.
危险品化学品经营许可证（带存储）