To alleviate photoinduced charge recombination in semiconducting nanomaterials represents an important endeavor toward high‐efficiency photocatalysis. Here a judicious integration of piezoelectric and photocatalytic properties of organolead halide perovskite CH3NH3PbI3 (MAPbI3) to enable a piezophotocatalytic activity under simultaneous ultrasonication and visible light illumination for markedly enhanced photocatalytic hydrogen generation of MAPbI3 is reported. The conduction band minimum of MAPbI3 is higher than hydrogen generation potential (0.046 V vs normal hydrogen electrode), thereby rendering efficient hydrogen evolution. In addition, the noncentrosymmetric crystal structure of MAPbI3 enables its piezoelectric properties. Thus, MAPbI3 readily responds to external mechanical force, creating a built‐in electric field for collective piezophotocatalysis as a result of effective separation of photogenerated charge carriers. The experimental results show that MAPbI3 powders exhibit superior piezophotocatalytic hydrogen generation rate (23.30 µmol h?1) in hydroiodic acid (HI) solution upon concurrent light and mechanical stimulations, much higher than that of piezocatalytic (i.e., 2.21 µmol h?1) and photocatalytic (i.e., 3.42 µmol h?1) hydrogen evolution rate as well as their sum (i.e., 5.63 µmol h?1). The piezophotocatalytic strategy provides a new way to control the recombination of photoinduced charge carriers by cooperatively capitalizing on piezocatalysis and photocatalysis of organolead halide perovskites to yield highly efficient piezophotocatalysis. 相似文献
A supercapacitor is usually stacked in the configuration of a layered sandwiched architecture, and has been adopted as discrete energy storage device or circuit component. However, this stacked structure decreases mechanical integrity, leads to low specific capacity, and prevents high‐density monolithic integration. Here all‐in‐one supercapacitors are fabricated by integrating cathode, anode, current collector, and separator into one monolithic glass fiber (GF) substrate together with other circuit components through matured and scalable fabrication techniques, the all‐in‐one supercapacitor is embedded as a component for 3D electronics. This all‐in‐one architecture demonstrates its effectiveness in the prevention of the delamination of the sandwiched supercapacitor and the minimization of the proportion of inactive materials. The supercapacitor delivers high power density (320 mW cm?3) and energy density (2.12 mWh cm?3), and exhibits a capacitance retention of 100% even after a continuous cycling of 431 h. Furthermore, a 3D polydimethylsiloxane/GF architecture is constructed for driving a flash light emitting diode system, where the all‐in‐one supercapacitor is monolithically integrated in the 3D system, and each layer is connected via vertical through‐holes. This all‐in‐one device can be constructed with a macroscopically available membrane and readily integrated into 3D systems without secondary packaging, providing the potential for high‐density heterogeneous 3D electronics. 相似文献
In 2012 and 2013, three and nine bat specimens were collected respectively from Nanling National Nature Reserve in Guangdong Province and Jinggangshan National Nature Reserve in Jiangxi Province. All specimens were small sized with forearm length of 30.51 to 34.62 mm and orange-yellow ventral fur. Based on their external and skull characteristics, they were identified as Murina shuipuensis; a newly named species reported by Eger and Lim (2011) from Guizhou. These are the first recorded in the Guangdong and Jiangxi provinces outside of its type locality (Shuipu Village, Libo County, Guizhou, China). All specimens were deposited in the Key Laboratory of Conservation and Application in Biodiversity of South China in Guangzhou University. 相似文献
Slow light devices with buffering capability play a critical role in all-optical signal processing. In this paper, multiple slow light phenomena are implemented based on plasmon-induced transparency (PIT) in our device. The device mainly consists of dual tooth cavities coupled with stub resonators, respectively. Temporal coupled-mode theory model illustrates that the triple PIT phenomena can be achieved based on different formation mechanisms. The simulation results calculated by the finite-difference time-domain method reveal that significant slow light response occurs at two wavelength regions. In addition, the parameters of structure have an important influence on PIT response and slow light characteristics. Moreover, the separate manipulation of wavelength, transmission and group index at transparency peak can be achieved in different slow light channels by adjusting the structural parameters. This plasmonic device is of great significance for the design of optical networks on chips.