Ningbo Polytechnic

The field of flexible electronics is a crucial driver of technological advancement, with a strong connection to human life and a unique role in various areas such as wearable devices and healthcare. Consequently, there is an urgent demand for flexible energy storage devices (FESDs) to cater to the energy storage needs of various forms of flexible products. FESDs can be classified into three categories based on spatial dimension, all of which share the features of excellent electrochemical performance, reliable safety, and superb flexibility. In this review, the application scenarios of FESDs are introduced and the main representative devices applied in disparate fields are summarized first. More specifically, it focuses on three types of FESDs in matched application scenarios from both structural and material aspects. Finally, the challenges that hinder the practical application of FESDs and the views on current barriers are presented.

Thermally activated delayed fluorescence (TADF) materials have attracted great potential in the field of organic light-emitting diodes (OLEDs). Among thousands of TADF materials, highly twisted TADF emitters have become a hotspot in recent years. Compared with traditional TADF materials, highly twisted TADF emitters tend to show multi-channel charge-transfer characters and form rigid molecular structures. This is advantageous for TADF materials, as non-radiative decay processes can be suppressed to facilitate efficient exciton utilization. Accordingly, OLEDs with excellent device performances have also been reported. In this Review, we have summarized recent progress in highly twisted TADF materials and related devices, and give an overview of the molecular design strategies, photophysical studies, and the performances of OLED devices. In addition, the challenges and perspectives of highly twisted TADF molecules and the related OLEDs are also discussed.

Abstract Aqueous zinc‐ion batteries are highly desirable for sustainable energy storage, but the undesired Zn dendrites growth severely shortens the cycle life. Herein, a triple‐gradient electrode that simultaneously integrates gradient conductivity, zincophilicity, and porosity is facilely constructed for a dendrite‐free Zn anode. The simple mechanical rolling‐induced triple‐gradient design effectively optimizes the electric field distribution, Zn 2+ ion flux, and Zn deposition paths in the Zn anode, thus synergistically achieving a bottom‐up deposition behavior for Zn metals and preventing the short circuit from top dendrite growth. As a result, the electrode with triple gradients delivers a low overpotential of 35 mV and operates steadily over 400 h at 5 mA cm ‐2 /2.5 mAh cm ‐2 and 250 h at 10 mA cm ‐2 /1 mAh cm ‐2 , far surpassing the non‐gradient, single‐gradient and dual‐gradient counterparts. The well‐tunable materials and structures with the facile fabrication method of the triple‐gradient strategy will bring inspiration for high‐performance energy storage devices.

Design and development of high-efficiency and durable oxygen evolution reaction (OER) electrocatalysts is crucial for hydrogen production from seawater splitting. Herein, we report the in situ electrochemical conversion of a nanoarray of Ni(TCNQ)2 (TCNQ = tetracyanoquinodimethane) on graphite paper into Ni(OH)2 nanoparticles confined in a conductive TCNQ nanoarray (Ni(OH)2-TCNQ/GP) by anode oxidation. The Ni(OH)2-TCNQ/GP exhibits high OER performance and demands overpotentials of 340 and 382 mV to deliver 100 mA·cm−2 in alkaline freshwater and alkaline seawater, respectively. Meanwhile, the Ni(OH)2-TCNQ/GP also demonstrates steady long-term electrochemical durability for at least 80 h under alkaline seawater.

This article provides a broad spectrum about the nanoprodrug fabrication advances co-driven by prodrug and nanotechnology development to potentiate cancer treatment. The nanoprodrug inherits the features of both prodrug concept and nanomedicine know-how, attempts to solve underexploited challenge in cancer treatment cooperatively. Prodrugs can release bioactive drugs on-demand at specific sites to reduce systemic toxicity, this is done by using the special properties of the tumor microenvironment, such as pH value, glutathione concentration, and specific overexpressed enzymes; or by using exogenous stimulation, such as light, heat, and ultrasound. The nanotechnology, manipulating the matter within nanoscale, has high relevance to certain biological conditions, and has been widely utilized in cancer therapy. Together, the marriage of prodrug strategy which shield the side effects of parent drug and nanotechnology with pinpoint delivery capability has conceived highly camouflaged Trojan horse to maneuver cancerous threats.

Oxygen vacancy-enriched Co 3 O 4 nanosheet arrays enable ambient electrosynthesis of NH 3 via nitrate reduction, achieving a faradaic efficiency of 96.9% and a NH 3 yield of 12 157 μg h −1 cm −2 in 0.1 M NaOH with 0.1 M NO 3 − .

CO2 capture and sequestration based on hydrate technology are considered supplementary approaches for reducing carbon emissions and mitigating the greenhouse effect. Direct CO2 hydrate formation and CH4 gas substitution in natural gas hydrates are two of the main methods used for the sequestration of CO2 in hydrates. In this Review, we introduce the crystal structures of CO2 hydrates and CO2–mixed gas hydrates and summarize the interactions between the CO2 molecules and clathrate hydrate/H2O frames. In particular, we focus on the role of diffraction techniques in analyzing hydrate structures. The kinetic and thermodynamic properties then are introduced from micro/macro perspectives. Furthermore, the replacement of natural gas with CO2/CO2–mixed gas is discussed comprehensively in terms of intermolecular interactions, influencing factors, and displacement efficiency. Based on the analysis of related costs, risks, and policies, the economics of CO2 capture and sequestration based on hydrate technology are explained. Moreover, the difficulties and challenges at this stage and the directions for future research are described. Finally, we investigate the status of recent research related to CO2 capture and sequestration based on hydrate technology, revealing its importance in carbon emission reduction.

Both doping and compositing in TiO2 are exceedingly effective strategies to overcome the compound’s shortcomings, such as invalid visible-light response and enormous recombination of photogenerated carriers. Herein, a convenient and cost-effective route has been put forward to in situ synthesize nanolayered heterostructure based on N-doped TiO2 nanoparticles and N-doped carbon (N-TiO2/NC) using 2D layered N-MXene (N–Ti3C2Tx) as the template. The as-obtained N-TiO2/NC nanocomposite displays greatly enhanced visible light absorption property, superior carrier separation and transport ability. As a result, the nanolayered N-TiO2/NC heterostructure exhibits a satisfactory H2 evolution rate from water-splitting (102.6 μmol g–1 h–1) under visible-light without any additional cocatalyst. The study provides a new strategy for the synthesis of defective nanoheterostructure and expands the applications of MXene family.

The practical application of electrochemical water splitting has been plagued by the sluggish kinetics of bubble generation and the slow escape of bubbles which block reaction surfaces at high current densities. Here, 3D-printed Ni (3DP Ni) electrodes with a rationally designed periodic structure and surface chemistry are reported, where the macroscopic ordered pores allow fast bubble evolution and emission, while the microporosity ensures a high electrochemically active surface area (ECSA). When they are further loaded with MoNi4 and NiFe layered double hydroxide active materials, the 3D electrodes deliver 500 mA cm–2 at an overpotential of 104 mV for the hydrogen evolution reaction (HER) and 310 mV for the oxygen evolution reaction (OER), respectively. An all-3D-printed alkaline electrolyzer (including electrodes, membrane, and cell) delivers 500 mA cm–2 at a remarkable voltage of 1.63 V with no noticeable performance decay after 1000 h. Such a tailored bubble trajectory demonstrates feasible solutions for future large-scale clean energy production.

Although much research has been devoted to the study of the impact of celebrity endorsements on the effectiveness of advertising in the literature on consumer behavior, few scholars pay attention to applying this concept to explain consumer behavior in the tourism field. This research tested celebrities’ expertise, trustworthiness, and attractiveness as the antecedents of consumer trust and engagement in the tourism and hospitality context. Specifically, through the analysis of 406 valid responses collected by online questionnaire, this study makes the following conclusions. First, it provides a new perspective on the influence of celebrity effects by focusing on the live-streaming behavior of CEOs on China’s largest online travel agency (OTA) platform. Secondly, it confirms that the three dimensions of the celebrity effect (expertise, trustworthiness, and attractiveness) positively affect the three dimensions of consumer trust (ability, benevolence, and integrity). At the same time, consumer trust can also predict the three dimensions of consumer engagement (cognitive processing, affection, and activation). In addition, the three dimensions of consumer trust also play a positive mediating role between the relationship of celebrity effects and consumer engagement. That is, the celebrity effects have a positive and indirect influence on consumer engagement. Therefore, by suggesting that celebrity endorsements can create consumer trust and engagement in the OTA platform, this research expands the research framework of celebrity endorsement credibility theory.

Research has focused on creating new methodologies such as supervised machine learning algorithms that can easily calculate the mechanical properties of fiber-reinforced concrete. This research aims to forecast the flexural strength (FS) of steel fiber-reinforced concrete (SFRC) using computational approaches essential for quick and cost-effective analysis. For this purpose, the SFRC flexural data were collected from literature reviews to create a database. Three ensembled models, i.e., Gradient Boosting (GB), Random Forest (RF), and Extreme Gradient Boosting (XGB) of machine learning techniques, were considered to predict the 28-day flexural strength of steel fiber-reinforced concrete. The efficiency of each method was assessed using the coefficient of determination (R2), statistical evaluation, and k-fold cross-validation. A sensitivity approach was also used to analyze the impact of factors on predicting results. The analysis showed that the GB and RF models performed well, and the XGB approach was in the acceptable range. Gradient Boosting showed the highest precision with an R2 of 0.96, compared to Random Forest (RF) and Extreme Gradient Boosting (XGB), which had R2 values of 0.94 and 0.86, respectively. Moreover, statistical and k-fold cross-validation studies confirmed that Gradient Boosting was the best performer, followed by Random Forest (RF), based on reduced error levels. The Extreme Gradient Boosting model performance was satisfactory. These ensemble machine learning algorithms can benefit the construction sector by providing fast and better analysis of material properties, especially for fiber-reinforced concrete.

Abstract Photoelectrochemical (PEC) water splitting with zero carbon emissions is a promising technology to solve the global issues of energy shortage and environmental pollution. However, the current development of PEC systems is facing a bottleneck of low solar‐to‐hydrogen (STH) efficiency (<10%), which cannot meet the demand of large‐scale H 2 production. The development of low‐cost, highly active, and stable photoanode materials is crucial for high STH efficiency of PEC water splitting. The recent development of BiVO 4 as photoanode materials for PEC water splitting has been a great success, and ABO 4 ‐type ternary metal oxides with a similar structure to BiVO 4 have high development potential as efficient photoanodes for high‐performance PEC water splitting. The design and development of ABO 4 photoanodes for PEC water splitting are critically reviewed with special emphasis on the modification strategies and performance improvement mechanisms of each semiconductor. The comprehensive analysis in this review provides guidelines and insights for the exploration of new high‐efficiency photoanodes for solar fuel production.

Perovskite solar cells have achieved rapid progress in the new-generation photovoltaic field, but the commercialization lags behind owing to the device stability issue under operational conditions. Ultimately, the instability issue is attributed to the soft lattice of ionic perovskite crystal. In brief, metal halide perovskite materials are susceptible to structural instability processes, including phase segregation, component loss, lattice distortion, and fatigue failure under harsh external stimuli such as high humidity, strong irradiation, wide thermal cycles, and large stress. Developing self-healing perovskites to further improve the unsatisfactory operational stability of their photoelectric devices under harsh stimuli has become a cutting-edge hotspot in this field. This self-healing behavior needs to be studied more comprehensively. Therefore, the self-healing behavior of the metal halide perovskites and photovoltaics is classified and summarized in this review. By discussing recent advances, underlying mechanisms, strategies, and existing challenges, this review provides perspectives on self-healing of perovskite solar cells in the future.

Abstract Electroconductive hydrogels (ECHs) have been extensively explored as promising flexible materials for bioelectronics because of their tunable conductivity and tissue‐like biological and mechanical properties. ECHs can interact intimately with biosystems, transmit physiological signals, and are expected to revolutionize the convergence between organisms and electronics. However, there are still some challenges in utilizing ECHs as flexible materials for bioelectronics, such as mismatched stretchability with tissues, a lack of environmental adaptability, susceptibility to mechanical damage, inferior interface compatibility, and vulnerability to bacterial contamination. This review categorizes these challenges encountered in the bioelectronic applications of ECHs and elaborates on the strategies and theories for improving their performance. Furthermore, we present an overview of the recent advancements in ECHs for bioelectronic applications, specifically focusing on their contributions to healthcare monitoring, treatment of diseases, and human–machine interfaces. The scope of future research on ECHs in bioelectronics is also proposed. Overall, this review offers a comprehensive exposition of difficult issues and potential opportunities for ECHs in bioelectronics, offering valuable insights for the design and fabrication of ECH‐based bioelectronic devices.

Abstract Zinc powder is promising for rechargeable zinc‐ion batteries due to its low cost and well tunability. However, the corrosion and the dendrite growth are much more serious in zinc powder than those in conventional zinc foils, which poses a significant obstacle to wide utilization. Herein, an ultra‐stable Zn powder‐based anode constructed by coating a conformal ion‐conductive hydrogel layer on 3D‐printed Zn scaffolds is reported. The interconnected hydrogel effectively redistributes the zinc ion flux and homogenizes the surface electric field, while the 3D architecture alleviates the stress from volume change at high current densities/capacities. As a result, the 3D Zn powder‐based symmetric cell steadily works for over 4700 h (>6 months) at a high current density/capacity of 5 mA cm −2 /5 mAh cm −2 , which is superior to previously reported Zn powder‐based anodes and bare Zn foil, providing a promising route for practical applications of low‐cost and large‐scale zinc‐ion batteries.

The transition metal trichalcogenides (TMTCs) are quasi-one-dimensional (1D) MX3-type van der Waals layered semiconductors, where M is a transition metal element of groups IV and V, and X indicates chalcogen element. Due to the unique quasi-1D crystalline structures, they possess several novel electrical properties such as variable bandgaps, charge density waves, and superconductivity, and highly anisotropic optical, thermoelectric, and magnetic properties. The study of TMTCs plays an essential role in the 1D quantum materials field, enabling new opportunities in the material research dimension. Currently, tremendous progress in both materials and solid-state devices has been made, demonstrating promising applications in the realization of nanoelectronic devices. This review provides a comprehensive overview to survey the state of the art in materials, devices, and applications based on TMTCs. Firstly, the symbolic structure, current primary synthesis methods, and physical properties of TMTCs have been discussed. Secondly, examples of TMTC applications in various fields are presented, such as photodetectors, energy storage devices, catalysts, and sensors. Finally, we give an overview of the opportunities and future perspectives for the research of TMTCs, as well as the challenges in both basic research and practical applications.

Abstract The search for color‐tunable, efficient, and robust scintillators plays a vital role in the development of modern X‐ray radiography. The radioluminescence tuning of copper iodide cluster scintillators in the entire visible region by bandgap engineering is herein reported. The bandgap engineering benefits from the fact that the conduction band minimum and valence band maximum of copper iodide cluster crystals are contributed by atomic orbitals from the inorganic core and organic ligand components, respectively. In addition to high scintillation performance, the as‐prepared crystalline copper iodide cluster solids exhibit remarkable resistance toward both moisture and X‐ray irradiation. These features allow copper iodide cluster scintillators to show particular attractiveness for low‐dose X‐ray radiography with a detection limit of 55 nGy s −1 , a value ≈100 times lower than a standard dosage for X‐ray examinations. The results suggest that optimizing both inorganic core and organic ligand for the building blocks of metal halide cluster crystals may provide new opportunities for a new generation of high‐performance scintillation materials.

Metal nanoparticles occupy an important position in electrocatalysis. Unfortunately, by using conventional synthetic methodology, it is a great challenge to realize the monodisperse composition/structure of metal nanoparticles at the atomic level, and to establish correlations between the catalytic properties and the structure of individual catalyst particles. For the study of well-defined nanocatalysts, great advances have been made for the successful synthesis of nanoparticles with atomic precision, notably ligand-passivated metal nanoclusters. Such well-defined metal nanoclusters have become a type of model catalyst and have shown great potential in catalysis research. In this review, the authors summarize the advances in the utilization of atomically precise metal nanoclusters for electrocatalysis. In particular, the factors (e.g., size, metal doping/alloying, ligand engineering, support materials as well as charge state of clusters) affecting selectivity and activity of catalysts are highlighted. The authors aim to provide insightful guidelines for the rational design of electrocatalysts with high performance and perspectives on potential challenges and opportunities in this emerging field.

The manufacturing process of ultra-high-performance concrete (UHPC) leads to a considerable amount of greenhouse gas emissions, which contribute to global warming. Using recycled concrete aggregates (RCA) to replace natural sand helps to reduce natural resources and energy consumption. In this study, the feasibility of manufacturing UHPC with fine RCA was investigated for the sustainable development of construction materials industry. We aimed to study the rheological properties, autogenous shrinkage, mechanical properties, and pore structure of UHPC with different amounts of RCA. The natural aggregate content was replaced with fine RCA at rates of 0, 20, 40, 60, 80, and 100 wt.%, and the packing density of the mixed fine aggregates in this study was estimated using a linear packing model. It was found that (1) the workability, mechanical properties, and deformation behaviour of UHPC with fine RCA were comparable to or even higher than those of UHPC made of high-quality aggregates; (2) the optimal replacement rate of fine RCA was in the range of 40-60 wt.%, considering the mechanical properties and deformation behaviour of UHPC; (3) the tensile strength, flexural strength, and Young's modulus of UHPC increased by 6.18%, 12.82%, and 3.40%, respectively, when the replacement rate of fine RCA was 60 wt.%; (4) the maximum packing density of mixed fine aggregates presented a monotonic decreasing trend as the replacement percentage of fine RCA increased. These findings help to encourage and further promote the utilisation of RCA to produce UHPC.

Abstract Alkaline hydrogen evolution reaction (HER) for scalable hydrogen production largely hinges on addressing the sluggish bubble‐involved kinetics on the traditional Ni‐based electrode, especially for ampere‐level current densities and beyond. Herein, 3D‐printed Ni‐based sulfide (3DPNS) electrodes with varying scaffolds are designed and fabricated. In situ observations at microscopic levels demonstrate that the bubble escape velocity increases with the number of hole sides (HS) in the scaffolds. Subsequently, we conduct multiphysics field simulations to illustrate that as the hole shapes transition from square, pentagon, and hexagon to circle, where a noticeable reduction in the bubble‐attached HS length and the pressure balance time around the bubbles results in a decrease in bubble size and an acceleration in the rate of bubble escape. Ultimately, the 3DPNS electrode with circular hole configurations exhibits the most favorable HER performance with an overpotential of 297 mV at the current density of up to 1000 mA cm −2 for 120 h. The present study highlights a scalable and effective electrode scaffold design that promotes low‐cost and low‐energy green hydrogen production through the ampere‐level alkaline HER.