Publications

Abstract Tailoring nanoparticles’ composition and morphology is of particular interest for improving their performance for catalysis. A challenge of this approach is that the nanoparticles’ optimized initial structure often changes during use. Visualizing the three dimensional (3D) structural transformation in situ is therefore critical, but often prohibitively difficult experimentally. Although electron tomography provides opportunities for 3D imaging, restrictions in the tilt range of in situ holders together with electron dose considerations limit the possibilities for in situ electron tomography studies. Here, an in situ 3D imaging methodology is presented using single particle reconstruction (SPR) that allows 3D reconstruction of nanoparticles with controlled electron dose and without tilting the microscope stage. This in situ SPR methodology is employed to investigate the restructuring and elemental redistribution within a population of PtNi nanoparticles at elevated temperatures. The atomic structure of PtNi is further examined and a heat‐induced transition is found from a disordered to an ordered phase. Changes in structure and elemental distribution are linked to a loss of catalytic activity in the oxygen reduction reaction. The in situ SPR methodology employed here can be extended to a wide range of in situ studies employing not only heating, but gaseous, aqueous, or electrochemical environments to reveal in‐operando nanoparticle evolution in 3D.

Abstract Ship draft measurement is of great significance for ensuring navigation safety and facilitating ship control. In this work, a self‐powered water level sensor based on a liquid–solid tubular triboelectric nanogenerator (LST‐TENG) is proposed and analyzed. The LST‐TENG is made of multiple copper electrodes uniformly distributed along a polytetrafluoroethylene (PTFE) tube. When water flows into the PTFE tube, it induces alternating flows of electrons between the main electrode and the distributed bottom electrodes. The obvious peaks in the derivative of open‐circuit voltage with respect to time are found to correspond with the electrode distribution. Then it can be utilized as a robust and sensitive indicator for detecting the water level as the number of obvious peaks in the derivative of open‐circuit voltage is directly related to the water level height. The ship draft is successfully detected using the LST‐TENG with an accuracy of 10 mm. It shows that the water level sensor has stable performance for liquid–solid interface monitoring. Therefore, this LST‐TENG is self‐powered, robust, and accurate for extensive applications in marine industry.

As a renewable energy harvesting technology, triboelectric nanogenerator (TENG), especially its flexible design, makes TENG highly compatible in the hybrid generator field. On the other hand, the flow augmentation electromagnetic generator (EMG) is widely studied. However, the wind energy flowing through the wind deflector is not effectively harvesting. This paper puts forward a wind-gathering enhanced triboelectric-electromagnetic hybrid generator (WGE-TEHG). Coupling the thin-film vibrating TENG and the wind deflector in the traditional flow augmentation EMG, besides the WGE-TEHG retains the function of flow augmentation EMG, the also generates additional power output by integrating the wind deflector of the TENG. The experimental results show that the WGE-TEHG as a generator for harvesting wind energy, which can output a total power of 212.4 mW. In addition, the WGE-TEHG can build a self-powered natural environment micro-meteorological sensing system. It can transmit wind direction, wind speed, temperature, and relative humidity in the environment. This research is of great value for coupling TENG and EMG.

A fully packaged hemispheres-array-structured triboelectric nanogenerator (H-TENG) that can endure severe environments is reported. The hemispheres-array-structure plays a dual role as the triboelectric material and an elastic "spring" to keep the two opposite materials separated for inducing the electrostatic effect during contact-separation cycle. H-TENGs can be applicable as an active self-powered sensor array to detect the distribution of external pressure.

A modified centrifuge has been developed. There are four advantages to this apparatus: (i) The presence of centrifugal acceleration permits the formation of the boundary between the two phases of a fluid system more quickly after phase separation, especially for viscous fluids such as polymer blends. (ii) The rotor is able to accommodate three samples. (iii) The formation of homogeneous solutions in the one phase region can be achieved within the constant temperature rotor which can be controlled to ±0.003 °C up to ≊300 °C. (iv) The phase separation temperature can be measured as a function of centrifugal acceleration up to 1500 gravity. By using the centrifugal apparatus, the coexistence curves of polystyrene in methylcyclohexane were measured. The results in terms of critical exponents and preexponential factors were in excellent agreement with the best literature values and thus confirmed the reliability of our apparatus.

Abstract A triboelectric nanogenerator (TENG) based self‐powered system for wind energy harvesting introduces a desirable solution to alleviate the expanding energy supply concerns in the development of the internet of things. In this work, an auto‐switching self‐powered system based on a dual‐rotation shaft TENG (D‐TENG) is reported to effectively harvest wind energy over a broad‐band wind speed (2.2–16 m s −1 ). The D‐TENG is designed in a concentric dual‐rotation shaft structure, in which two independent TENGs with different shapes, sizes, and arm lengths of wind cups are rationally coupled. The integration of the two TENGs with varied structural parameters achieves mutual compensation of their own merits, enabling the whole system to have preferable aerodynamics and high energy conversion efficiency over a broad range of wind speeds. Moreover, an electromagnetic generator (EMG) with the same energy collection module is also fabricated for a comparison with TENG in the start‐up properties and average output power. Furthermore, a packaged self‐powered system is demonstrated for simulated wind energy harvesting, while the charging characteristics are also discovered. The proposed TENG renders a more efficient technique for energy harvesting and greatly expands its potential in the large‐scale wind energy harvesting that can be attributed to the multi‐stage strategy.

The structural and magnetic properties of rare-earth nanocomposite magnets of a (Nd,Dy)(Fe,Co,Nb,B)5.5 single layer and a (Nd,Dy)(Fe,Co,Nb,B)5.5/α-Fe multilayer prepared by sputtering and heat treatment have been investigated. Incomplete exchange coupling behaviour is observed in the Ti-buffered NdDyFeCoNbB + 40 wt%Fe single layer magnet. After annealing, the laminated nanostructure consisting of mutually dispersed soft and hard phases results in remanence enhancement. The optimum magnetic properties of Jr = 1.11 T, μ0iHc = 0.88 T and (BH)max = 192 kJ m−3 are achieved in the multilayer magnet annealed at 550°C for 30 min. The designed multilayer film with thinner soft magnetic layers may favour the formation of more ideal nanostructures for exchange coupling between soft- and hard-magnetic phases.

The piezo-phototronic effect plays an ingenious and robust role in modulating the optoelectronic processes of photocatalysis, solar cells, photodetectors and light-emitting diodes by tuning energy band structures and photoinduced carrier behaviors.

Abstract General‐purpose computers usually use logic gate computing units based on complementary metal oxide semiconductors (CMOS). Due to the separate memory and computing units in Von Neumann architecture, data transmission requires great energy and time consumption. Developing novel neuromorphic devices and comprehensively investigating their logical computing mode are crucial to achieve high‐performance and low‐power neuromorphic computation. Here, a systematic summary of Boolean logic computing based on emerging neuromorphic transistors is presented. This summary encompasses logical operation modes, materials, device structures, and working mechanisms. The input mode of Boolean logic operation is classified into electrical input, optical input, and synergistic optical/electrical input. Besides, additional modulation strategies to construct programmable logic functions by electrical, optical, and thermal signals are also summarized. These strategies hold great significance as they enable dynamic reconfiguration of logic operations and provide neuromorphic devices with decision‐making capabilities. Finally, the application prospects and current challenges to Boolean logic computing based on dendritic integration are discussed from the aspects of device integration, synergistic input/modulation modes, auxiliary peripheral circuit, software/hardware system, etc. It is believed that comprehensive investigations on neuromorphic Boolean logic operations are crucial to push forward the development of future neuromorphic computing toward high efficiency and high integration density.

Abstract Triboelectric nanogenerator (TENG), as a new technique for energy capture, has unique advantages in harvesting high‐entropy energy. In view of the wind‐induced vibration characteristics of power transmission lines, the symmetric elastic bistable triboelectric nanogenerator (EB‐TENG) is introduced in this work. The core component of the EB‐TENG is the elastic bistable cantilever beam structure, which is designed by introducing an elastic perturbation structure to the conventional cantilever beam. This beam results in several sub‐resonance frequencies in addition to the natural frequencies, which broadens the frequency band of the EB‐TENG. In addition, the EB‐TENG adopts a symmetrical cantilever beam to ensure effective harvesting of vibration energy, even in situations of self‐tilting and external tilting vibration. The experimental outcomes confirm that the EB‐TENG can significantly harvest vibration energy in the 7–60 Hz frequency range and delivers the maximum peak power of 2.846 mW, which meets the major vibration frequency range of power transmission lines under the action of breeze. Finally, self‐powered strategy based on EB‐TENG online monitoring devices (such as tower obstruction lights, temperature and humidity sensors, and line high temperature wireless alarms) is constructed. This work helps promote the application of in‐situ self‐powered monitoring based on TENG in smart transmission lines.