Publications

We report the synthesis of ZnO nanotubes grown via the Ga-catalyzed vapor transport method at low temperature and their photocatalytic activity. The low melting point of Ga (29 °C) resulted in the growth of ZnO nanotubes at a low temperature of 80 °C, enabling us to use Kapton film or ITO glass as substrates. Structure analysis shows that the nanotube is single crystal and has a hollow structure with a wall thickness of ∼2 nm, is several tens of micrometers long, and has a diameter of 60−300 nm. Photocatalytic activity of ZnO nanotubes was determined by measuring the photoinduced degradation of rhodamine B (RB) and an azobenzene-containing polymer poly{1-4[4-(3-carboxy-4-hydroxyphenyl-azo)benzenesulfonamido]-1,2-ethanediyl sodium salt} (PAZO) solution, respectively. The measurement reveals that the photodecomposition reactions of both RB and PAZO follow the first-order rate law with the rate constant of 0.018 and 0.004 s−1, respectively. The photocatalytic activity of ZnO nanotubes was shown to be much enhanced compared with ZnO thin films and ZnO nanowires. Therefore, this work demonstrates a novel and simple way to synthesize ZnO nanotubes on flexible substrates, which can potentially serve as excellent photocatalysts for the degradation of organic pollutants in water.

Abstract Natural wind energy harvesting enables a far‐reaching and sustainable solution to supply pervasive sensors in the Internet of Things (IoT). Electromagnetic generators (EMGs) struggle to harvest energy from breezes, which causes regrettable energy wastage. Herein, a triboelectric‐electromagnetic hybridized nanogenerator (TEHG) is designed with a dual‐rotor structure to consolidate harvesting band for high efficiency of triboelectric nanogenerators (TENGs) in breeze and the EMG in high wind speeds. The TEHG performs an efficient energy collection (41.05 W m −3 ) and a smooth output in the wind speed of 2−16 m s −1 , attributed to the environmental self‐adaptive cooperation between TENGs and EMGs. The TENG output power contribution is more than 70% at low wind speeds (<5 m s −1 ). Moreover, a dual‐channel power management topology (DcPMT) is established to co‐manage outputs of two modules in TEHG. By virtue of the DcPMT hierarchically combining the isolated storage with undervoltagelockout strategy, the TEHG steadily supplies a standardized 3.3 V voltage for commercial electronics. Furthermore, a TEHG‐based self‐powered system is demonstrated for driving sensors to monitor meteorological information. The TEHG with DcPMT is advantageous in broad‐band and high‐efficiency of wind energy harvesting, thus exhibiting a great potential for elevating the environmental self‐adaptability and stability margin of the IoT.

Nanogenerators were first demonstrated by deflecting aligned ZnO nanowires using a conductive atomic force microscopy (AFM) tip. The output of a nanogenerator is affected by three parameters: tip normal force, tip scanning speed, and tip abrasion. In this work, systematic experimental studies have been carried out to examine the combined effects of these three parameters on the output, using statistical design of experiments. A statistical model has been built to analyze the data and predict the optimal parameter settings. For an AFM tip of cone angle 70° coated with Pt, and ZnO nanowires with a diameter of 50 nm and lengths of 600 nm to 1 μm, the optimized parameters for the nanogenerator were found to be a normal force of 137 nN and scanning speed of 40 μm/s, rather than the conventional settings of 120 nN for the normal force and 30 μm/s for the scanning speed. A nanogenerator with the optimized settings has three times the average output voltage of one with the conventional settings.

Abstract Accompanying the boom in multifunctional wearable electronics, flexible, sustainable, and wearable power sources are facing great challenges. Here, a stretchable, washable, and ultrathin skin‐inspired triboelectric nanogenerator (SI‐TENG) to harvest human motion energy and act as a highly sensitive self‐powered haptic sensor is reported. With the optimized material selections and structure design, the SI‐TENG is bestowed with some merits, such as stretchability ( ≈ 800%), ultrathin ( ≈ 89 µ m), and light‐weight ( ≈ 0.23 g), which conformally attach on human skin without disturbing its contact. A stretchable composite electrode, which is formed by homogenously intertwining silver nanowires (AgNWs) with thermoplastic polyurethane (TPU) nanofiber networks, is fabricated through synchronous electrospinning of TPU and electrospraying of AgNWs. Based on the triboelectrification effect, the open‐circuit voltage, short‐circuit current, and power density of the SI‐TENG with a contact area of 2 × 2 cm 2 and an applied force of 8 N can reach 95 V, 0.3 µ A, and 6 mW m −2 , respectively. By integrating the signal‐processing circuits, the SI‐TENG with excellent energy harvesting and self‐powered sensing capability is demonstrated as a haptic sensor array to detect human actions. The SI‐TENG exhibits extensive applications in the fields of human–machine interface and security systems.

Ein integriertes System aus einem Mehrfarben-Hybridphotodetektor (Kohlenstofffaser und ZnO-Nanodraht (NW)) wird durch eine mikrobielle Brennstoffzelle angetrieben (siehe Bild; PMMA=Polymethylmethacrylat, E=Elektrode). Dieser Photodetektor ohne externe Stromquelle kann Licht selbst bei einer Intensität im nW cm−2-Bereich mit einer Empfindlichkeit von mehr als 300 A W−1 detektieren. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Abstract Background Portal vein thrombosis（PVT） is a common complication of liver cirrhosis, yet there are fewer studies about predictors of PVT recanalization. We aimed to further explore the predictors of recanalization in cirrhotic PVT to facilitate accurate prediction of patients' clinical status and timely initiation of appropriate treatment and interventions. We also further investigated the benefits and risks of anticoagulation therapy in patients with cirrhotic PVT are further investigated. Methods A retrospective cohort study of patients with cirrhotic PVT in our hospital between January 2016 and December 2022, The primary endpoint was to analyze predictors of PVT recanalization by COX regression. Others included bleeding rate, liver function, and mortality. Results This study included a total of 82 patients, with 30 in the recanalization group and 52 in the non-recanalization group. Anticoagulation therapy was the only independent protective factor for portal vein thrombosis recanalization and the independent risk factors included massive ascites, history of splenectomy, Child-Pugh B/C class, and main trunk width of the portal vein. Anticoagulation therapy was associated with a significantly higher rate of PVT recanalization (75.9% vs. 20%, log-rank P <0.001) and a lower rate of PVT progression (6.9% vs. 54.7%, log-rank P=0.002). There was no significant difference between different anticoagulation regimens for PVT recanalization. Anticoagulation therapy did not increase the incidence of bleeding complications(P=0.407). At the end of the study follow-up, Child-Pugh classification, Meld score, and albumin level were better in the anticoagulation group than in the non-anticoagulation group. There was no significant difference in 2-year survival between the two groups. Conclusion Anticoagulation, massive ascites, history of splenectomy, Child-Pugh B/C class, and main portal vein width were associated with portal vein thrombosis recanalization. Anticoagulation may increase the rate of PVT recanalization and decrease the rate of PVT progression without increasing the rate of bleeding. Anticoagulation may be beneficial in improving liver function in patients with PVT in cirrhosis.

Abstract Osmotic energy, also known as ‘blue energy’, harnesses the salinity gradient between seawater and freshwater, providing a vast, renewable, and environmentally friendly energy source. The efficiency of osmotic power generation is fundamentally dependent on the performance of ion-exchange membranes, where a critical trade-off exists between ion selectivity and ion permeability, which determine the voltage and current respectively. Recent advances in nanofluidic reverse electrodialysis (NRED) have leveraged nanoconfined spaces and innovative membrane design to significantly minimize resistance and promote energy conversion. In this review, we systematically explore the ion transport mechanisms in nanoconfined spaces, analyze state-of-the-art membrane optimization parameters to balance the selectivity-permeability trade-off. Finally, we discuss current challenges and prospective future directions for membrane innovation in NRED-based osmotic power generation systems, with the ultimate target of facilitating the practical realization of high-performance, commercially viable osmotic power generation.

Polymer piezoelectric nanogenerators (PENGs) have attracted extensive interest in mechanical energy conversion and wearable electronics for the advantages they have to offer owing some of their characteristics, e.g., the fact that they are light weight, possess a desirable flexibility, and benefit from a high adaptability and simple large-scale manufacturing processes. In this paper, a high-performance organic flexible PENG based on a poly(vinylidene fluoride-trifluorethylene) [P(VDF-TrFE)] film doped with a SnS nanosheet (NS) micropillar array has been prepared and characterized. The piezoelectric coefficient of the P(VDF-TrFE)/SnS NSs (0.3 wt. %) nanocomposite has been greatly enhanced compared with that of the pristine P(VDF-TrFE) film, from 13 to 21 pC N−1. It also demonstrates outstanding open-circuit voltage (Voc) and short-circuit current (Isc) outputs of 17.28 V cm−2 and 0.94 μA cm−2 under the pressure of 0.5 MPa, which represents a 6-fold and 4-fold improvement, respectively, compared with what a neat P(VDF-TrFE) film was able to deliver. The device was capable of producing a high output power density of 10.69 μW cm−2 under an applied pressure of 0.5 MPa. The dramatic enhancement obtained using nanocomposite micropillar array films results from a more developed β-phase content in the organic film, the higher piezoelectric properties of SnS NSs, and the better alignment of dipoles induced by the micropillar array structure. These remarkably enhanced PENG performances seem to hold much promise for the development of wearable electronics exploiting ambient mechanical energy, thanks to its ability to produce different signals depending on the nature of the source of stimuli.

Abstract Developing an applicable triboelectric nanogenerator (TENG) for train wheel energy harvesting is a key step to meet the urgent need of wheel safety monitoring. Herein, an innovative design of free‐fixed TENG (FF‐TENG) is reported, without a serious negative impact on the wheel. The key of this design is the magnets fixed on the device and bogie, providing attractive force to immobilize the stator. With a rotational structure, FF‐TENG can provide a high short‐circuit current of 55 µA, an open‐circuit voltage of 500 V, and a charge of 235 nC at a rotation speed of 400 rpm. At an external load resistance of 10 MΩ, FF‐TENG delivers the maximum power of 15.68 mW. Furthermore, the superior robustness of FF‐TENG in vibration environment is proved. In addition, a power management circuit designed by LTC 3588 is tested for more efficient capacitor charging, leading to better performance to power electronics. Finally, a self‐powered real‐time wheel temperature and wheel speed monitoring system is developed with FF‐TENG as a safety alert demo for feasibility demonstration. Given the rational structure design and high performance, this work paves a practical way for TENGs in the field of intelligent transportation.