Polymer-based nanodielectrics have been intensively investigated for their potential application as energy storage capacitors. However, their relatively low energy density (Ue) and discharging efficiency (η) may greatly limit their practical usage. In present work, high insulating two-dimensional boron nitride nanosheets (BNNS), were introduced into a linear dielectric polymer (P(VDF-TrFE-CTFE)-g-PMMA) matrix to enhance the energy storage performance of the composite. Thanks to the surface coating of polydopamine (PDA) on BN nanosheets, the composite filled with 6 wt% coated BNNS (mBNNS) exhibits significantly improved breakdown strength (Eb) of 540 MV/m and an energy density (Ue) of 11 J/cm3, which are increased by 23% and 100%, respectively as compared with the composite filled with the same content of pristine BNNS. Meanwhile, η of both composites is well retained at around 70% even under a high voltage of 400 MV/m, which is superior to most of the reported composites. This work suggests that complexing polymer matrix with linear dielectric properties with surface coated BNNS fillers with high insulating 2D structure might be a facile strategy to achieve composite dielectrics with simultaneously high energy density and high discharging efficiency.
The broadband polarization-insensitive saturable absorption of Fe2O3 nanoparticles has been demonstrated for generating Q-switched cylindrical vector beams.
The rapidly advancing improvements in perovskite solar cells (PSCs) are driven, in part, by the inclusion of suitable electron transport layers (ETLs) in high performance devices. Fullerene derivatives are particularly useful ETLs in PSCs, but many of the utilized fullerenes are present as isomeric mixtures. The opportunities presented by single‐isomer, single‐enantiomer fullerenes in PSCs are poorly understood. Here, inverted PSCs are prepared using bis[60]phenyl‐C61‐butyric acid methyl ester derivative (anti)16,17‐bis[60]PCBM, comparing the performance of enantiomerically pure material to the corresponding racemate. The single enantiomer devices are found to have an improved performance, giving a power conversion efficiency (PCE) of 23.2%, compared to 20.1% PCE for the racemate. It is also shown that enantiomerically pure PSC modules can be prepared with a state‐of‐the‐art PCE of 20.1%. Such excellent performance for the single enantiomer devices is accompanied by enhanced operational stability. This study thus provides strong evidence that single isomer ETLs can provide important improvements in PSC performance and it positions chiral fullerenes as an exciting material class moving forward.
Bimetallic noble-metal nanoparticles were synthesized in a containerless state via acoustic levitation. We chose oleylamine as stabilizer and borane-t-butylamine complex as reducing agent to prepare the Au–Ag nanoparticles in organic phase. The synthesis process, particle size distribution, morphology, optical property, chemical composition, and catalytic performance of prepared bimetallic nanoparticles were characterized and analyzed. The Au–Ag nanoparticles synthesized in acoustic levitation exhibited a smaller size, narrower distribution range, and improved catalytic performance in 4-nitrophenol reduction compared with the normal container condition. In acoustic levitation, the catalytic activity of equiatomic Au–Ag nanoparticles was significantly enhanced due to synergistic effects.