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The electrochemical CO 2 reduction reaction (CO 2 RR) to produce multicarbon (C 2+ ) hydrocarbons or oxygenate compounds is a promising route to obtain a renewable fuel or valuable chemicals; however, producing C 2+ at high current densities is still a challenge. Herein, we design a hierarchically structured tandem catalysis electrode for greatly improved catalytic activity and selectivity for C 2+ products. The tandem catalysis electrode is constructed of a sputtered Ag nanoparticle layer on a hydrophobic polytetrafluoroethylene (PTFE) membrane and a layer of nitrogen-doped carbon (NC)-modified Cu nanowire arrays. The Cu nanowire arrays are in situ grown on PTFE by electrochemical oxidation of sputtered CuAl alloy, in which the chemical etching of metal Al induces the formation of a Cu nanowire array structure. Within hierarchical configuration, CO can be efficiently generated on an active Ag layer and then spillover and transfer to NC-modified Cu nanowire array layer, in which Cu/NC interfaces can enhance *CO trapping and adsorption. During the CO 2 RR, the optimized tandem catalysis electrode achieves superior Faradaic efficiencies of 53.5% and 87.5% for ethylene (C 2 H 4 ) and C 2+ products at the current density of 519.0 mA cm -2 , respectively, with a high C 2+ /C 1 ratio of 10.42 and long-term stability up to 50 h. In situ Raman and attenuated total reflection-surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) confirm that the Ag-Cu-NC tandem catalysis system significantly enhances the linear adsorption of *CO intermediates and the dissociation of H 2 O, improves the C-C coupling capability, and stabilizes the key intermediate *OCCOH to produce C 2+ products.

The polymer-based triboelectric nanogenerator (TENG) has long grappled with the constraint of limited current density (CD), whereas semiconductor-based triboelectric nanogenerators, using the tribovoltaic effect, have shown promising potential for achieving high current density. This study introduces an effective solution─a direct current tribovoltaic nanogenerator with ultrahigh current density─founded on a flexible organic semiconductor textile activated by solvents. By introducing 95% ethyl alcohol, an ultrahigh current density of 8.75 A/m 2 and peak power density of 1.07 W/m 2 are demonstrated, marking a striking enhancement of 438-fold and 170-fold, respectively, in comparison to the friction surface without 95% ethyl alcohol. The activation mechanism is that the poly(vinyl alcohol) dissolution by solvents exposes more PEDOT:PSS, and the formation of hydrogen bonds with PSS- releases more active PEDOT+. This advancement finds practical utility, as evidenced by successful demonstrations involving cell phone charging and small motor propulsion. The breakthrough unveiled in this work presents vistas for the widespread application of flexible organic semiconductor textile-based tribovoltaic nanogenerators, offering exciting opportunities for biomechanical energy harvesting.

A Mn(III)-mediated radical cascade cyclization of N -propargyl enamides with sodium sulfinates was developed. Mechanistic studies indicated that this cascade process is mainly composed of the chemoselective addition of sulfonyl radical to C≡C bond and the regioselective intramolecular 6- endo -trig cyclization. This protocol provided a powerful method for the divergent synthesis of diverse polysubstituted meta -sulfonylpyridines or 1,2-dihydropyridines just by varying solvent and temperature featuring good functional group compatibility and simple operation.

A Ni-catalyzed protocol for the regioselective and stereoselective three-component fluoroalkylthiolation of alkynes with fluoroalkyl halides and thiosulfonates is presented. This reductive difunctionalization provides an efficient strategy for the rapid construction of fluoroalkyl-incorporated vinylthioethers under mild conditions in moderate to good yields.

Mechanochemistry revolutionizes traditional reactions through mechanical stimulation, but its reaction efficiency is limited. Recent advancements in utilizing triboelectric charge from liquid-solid contact electrification (CE) have demonstrated significant potential in improving the reaction efficiency. However, its efficacy remains constrained by interfacial electrical double-layer screening in aqueous solutions. This study pioneered chemistry in nonaqueous systems via CE for catalysis and luminescence. Density functional theory simulations and experiments revealed varying electron transfer capabilities and chemoselectivity of CE across different solvents. Phenol degradation via CE in dimethyl sulfoxide (DMSO) exhibited a rate over 40 times faster than that of traditional mechano-driven chemistry. A more intuitive comparison revealed that CE degradation of phenol in DMSO exhibits a 30-fold rate improvement compared to deionized water, where the degradation remains incomplete. Luminol oxidation by radicals generated solely via CE in DMSO eliminates the dependence on traditional catalysts and side reactions, establishing a pure and simple system for investigating the reaction mechanisms. A high and stable luminescence characteristic was maintained for 3 months, enhancing the imaging accuracy and stability exponentially. This study underscores the impact of triboelectric charge on reaction efficiency and chemoselectivity, establishing a new paradigm in nonmetal catalysis, mechanoluminescence, and providing profound insights into reaction kinetics.

As environmental energy harvesting gains increasing importance in self-powered systems and large-scale energy demands, wind energy, as a clean, pollution-free, and renewable source, has garnered widespread attention. However, achieving efficient wind energy collection remains challenging. This study proposes a high-performance rotating structure triboelectric-electromagnetic hybrid nanogenerator designed for environmental wind energy harvesting. By optimizing the magnetic circuit design of the electromagnetic generator, the dispersed radial magnetic field is converted into a unified axial magnetic field, enabling efficient power generation with only a single annular coil, thereby simplifying the generator design and reducing manufacturing and maintenance costs. Additionally, a triboelectric nanogenerator design with soft contact friction between polycarbonate (PC) fur and fluorinated ethylene propylene (FEP) film was implemented, optimizing the spacing between the electrode and friction layers, thus enhancing output performance and device durability. Furthermore, we simulated and experimentally tested the output waveform of the designed hybrid generator structure, with the results showing a high degree of similarity, further validating the rationality of the device design and providing guidance for structural optimization. Subsequently, we achieved efficient energy storage using an energy management circuit (EMC). With the integration of the EMC, the generator successfully powered a Bluetooth temperature and humidity sensor at a wind speed of 10 m/s, achieving wireless transmission, and demonstrating its potential application in traffic signal systems and other natural environmental systems. This research provides an important reference for further exploration of novel wind energy harvesting technologies.

Interfacial contact electrification can catalyze redox reactions through a process called contact-electro-catalysis (CEC). The two main reaction paths for producing reactive oxygen species via CEC are the water oxidation reaction (WOR) and the oxygen reduction reaction (ORR). Herein, we designed a polymer/metal Janus composite catalyst that regulated the reaction rates of the WOR and ORR based on the catalyst composition. The ORR was preferentially enhanced when the polymer was negatively charged during contact electrification, while the WOR was preferentially enhanced when the polymer was positively charged. This phenomenon was observed for various conductive materials. The increase in the enhancement of the reaction rates depended on the conductivity and work function of the metal. We expect that this efficient CEC method can form a universal strategy for improving the performance of existing catalysts, as contact electrification is common in nature.

A palladium-catalyzed [4 + 1] annulation of N -arylimidoyl chlorides with β-keto esters has been developed. In the presence of Pd(OAc) 2 , PCy 3 , and K 3 PO 4 , a variety of fluoalkyl-containing N -arylimidoyl chlorides smoothly underwent the cascade C-H imidoylation/deacylative Heck-type reactions to afford biologically important 2-fluoroalkyl indoles in moderate to good yields.

Here, we report a set of new polymerization reactions enabled by the 1,2-regioselective hydro- and silylcupration of enyne-type propargylic electrophiles. Highly regioregular head-to-tail poly(2-butyne-1,4-diyl)s (HT-PBD), bearing either methyl or silylmethyl side chains, are synthesized for the first time. A rapid entry into carbon-rich copolymers with adjustable silicon content is developed via in situ monomer bifurcation. Furthermore, a one-pot polymerization/semireduction sequence is developed to access a cis -poly(butadiene)-derived backbone by a ligand swap on copper hydride species. Interestingly, borocupration, typically exhibiting identical regioselectivity with its hydro- and silyl analogues, seems to proceed in a 3,4-selective manner. Computational studies suggest the possible role of the propargylic leaving group in this selectivity switch. This work presents a new class of regioregular sp -carbon-rich polymers and meanwhile a novel approach to organosilicon materials.

Triboelectric nanogenerators (TENGs) have garnered substantial attention in breeze wind energy harvesting. However, how to improve the output performance and reduce friction and wear remain challenging. To this end, a blade-type triboelectric-electromagnetic hybrid generator (BT-TEHG) with a double frequency up-conversion (DFUC) mechanism is proposed. The DFUC mechanism enables the TENG to output a high-frequency response that is 15.9 to 300 times higher than the excitation frequency of 10 to 200 rpm. Coupled with the collisions between tribomaterials, a higher surface charge density and better generating performance are achieved. The magnetization direction and dimensional parameters of the BT-TEHG were optimized, and its generating characteristics under varying rotational speeds and electrical boundary conditions were studied. At wind speeds of 2.2 and 10 m/s, the BT-TEHG can generate, respectively, power of 1.30 and 19.01 mW. Further experimentation demonstrates its capacity to charge capacitors, light up light emitting diodes (LEDs), and power wireless temperature and humidity sensors. The demonstrations show that the BT-TEHG has great potential applications in self-powered wireless sensor networks (WSNs) for environmental monitoring of intelligent agriculture.

Flexible tactile sensors show promise for artificial intelligence applications due to their biological adaptability and rapid signal perception. Triboelectric sensors enable active dynamic tactile sensing, while integrating static pressure sensing and real-time multichannel signal transmission is key for further development. Here, we propose an integrated structure combining a capacitive sensor for static spatiotemporal mapping and a triboelectric sensor for dynamic tactile recognition. A liquid metal-based flexible dual-mode triboelectric-capacitive-coupled tactile sensor (TCTS) array of 4 × 4 pixels achieves a spatial resolution of 7 mm, exhibiting a pressure detection limit of 0.8 Pa and a fast response of 6 ms. Furthermore, neuromorphic computing using the MXene-based synaptic transistor achieves 100% recognition accuracy of handwritten numbers/letters within 90 epochs based on dynamic triboelectric signals collected by the TCTS array, and cross-spatial information communication from the perceived multichannel tactile data is realized in the mixed reality space. The results illuminate considerable application possibilities of dual-mode tactile sensing technology in human-machine interfaces and advanced robotics.

Obtaining bioenergy from human movement is not only a prospective complementation to electrochemical power supply such as batteries in portable electronics but also a decipherable process for developing self-powered sensors that can simultaneously monitor the physiological movement. In this study, a low-cost, robust, and environmentally friendly triboelectric nanogenerator (TENG) was prepared with enhanced mechanical stability and tunneling conductivity on the base of cotton fabric. The as-designed TENG may produce energy sustainably by physical movements, and it can yield an amazing 417 V open-circuit voltage, 11.7 μA short-circuit current, and 237.60 mW/m 2 excellent power density, showcasing its potential for efficient energy conversion in the single-electrode mode. Besides, such a design also shows real-time tactile perception ability toward human physiological signal and body motion where intelligent application of these environmental benign TENGs in sports and writing training were demonstrated, thus providing vital instruction for the creation of versatile and sustainable TENGs in the Internet of Things era.

Electron transfer during solid-liquid contact electrification has been demonstrated to produce reactive oxygen species (ROS) such as hydroxyl radicals ( • OH) and superoxide anion radicals ( • O 2 - ). Here, we show that such a process also occurs in liquid-liquid contact electrification. By preparing perfluorocarbon nanoemulsions to construct a perfluorocarbon-water "liquid-liquid" interface, we confirmed that electrons were transferred from water to perfluorocarbon in ultrasonication-induced high-frequency liquid-liquid contact to produce • OH and • O 2 - . The produced ROS could be applied to ablate tumors by triggering large-scale immunogenic cell death in tumor cells, promoting dendritic cell maturation and macrophage polarization, ultimately activating T cell-mediated antitumor immune response. Importantly, the raw material for producing • OH is water, so the tumor therapy is not limited by the endogenous substances (O 2 , H 2 O 2 , etc.) in the tumor microenvironment. This work provides new perspectives for elucidating the mechanism of generation of free radicals in liquid-liquid contact and provides an excellent tumor therapeutic modality.

As tactile force sensing has become increasingly significant in the field of machine haptics, achieving multidimensional force sensing remains a challenge. We propose a 3D flexible force sensor that consists of an axisymmetric hemispherical protrusion and four equally sized quarter-circle electrodes. By simulating the device using a force and electrical field model, it has been found that the magnitude and direction of the force can be expressed through the voltage relationship of the four electrodes when the magnitude of the shear force remains constant and its direction varies within 0-360°. The experimental results show that a resolution of 15° can be achieved in the range 0-90°. Additionally, we installed the sensor on a robotic hand, enabling it to perceive the magnitude and direction of touch and grasp actions. Based on this, the designed 3D flexible tactile force sensor provides valuable insights for multidimensional force detection and applications.

Recently, the combination of the piezoelectric effect in the photocatalytic process, referred to as piezo-photocatalysis, has gained considerable attention as a promising approach for enhancing the degradation of organic pollutants. In this investigation, we studied the piezo-photocatalysis by fabricating arrays of barium strontium titanate (Ba 0.7 Sr 0.3 TiO 3 ) nanorods (BST NRs) on a glass substrate as recoverable catalysts. We found that the degradation rate constant k of the rhodamine B solution achieved 0.0447 min -1 using poled BST NRs in the piezo-photocatalytic process, indicating a 2-fold increase in efficiency compared to the photocatalytic process (0.00183 min -1 ) utilizing the same material. This is mainly ascribed to the generation of the piezopotential in the poled BST NRs under ultrasonic vibration. Moreover, the BST NR array demonstrated a hydrogen (H 2 ) production rate of 411.5 μmol g -1 h -1 . In the photoelectrochemical process, the photocurrent density of poled BST NRs achieved 1.97 mA cm -2 at an applied potential of 1.23 V ( E RHE (reversible hydrogen electrode)) under ultrasonic vibrations, representing a 1.7-fold increase compared with the poled BST NRs without ultrasonic vibrations. The measurement results from the liquid chromatograph mass spectrometer (LC-MS) demonstrated the formulation of a degradation pathway for rhodamine B molecules. Moreover, ab initio molecular dynamics (AIMD) simulation results demonstrate the dominance of hydroxyl radicals ( • OH) rather than superoxide radicals ( • O 2 - ) in the degradation process. This study not only benefits the understanding of the principle of the piezo-photocatalytic process but also provides a new perspective for improving the catalytic efficiency for organic pollutants degradation.

Hydrogels play a pivotal role in the realm of iontronics, contributing to the realization of futuristic human-machine interactions. The electric double layer (EDL) between the hydrogel and electrode provides an essential ionic-electronic coupling interface. While prior investigations primarily delved into elucidating the formation mechanism of the EDL, our study shifts the focus to showcasing the current generation through the mechanical modulation of the EDL at the hydrogel-metal interfaces. The dynamic EDL was constructed by the mechano-driven contact-separation process between the polyacrylamide (PAAm) hydrogel and Au. Influencing factors on the dynamic regulation of the EDL such as ion concentration, types of salt, contact-separation frequency, and deformation degree were investigated. Dehydration usually limits the practical applications of hydrogels, and it is a long-standing and difficult problem. However, it seemed to be able to slow the EDL formation process here, resulting in a sustained continuous direct current signal output. Such hydrogel iontronics could rectify the displacement electronic current of a triboelectric nanogenerator by the ionic current. The directional migration of ions could be further enhanced by using charge-collecting metals with different work functions, for example, Au and Al. It offers a paradigm to enable ionic rectification that could be seamlessly incorporated into electronic systems, ushering in a new era for efficient energy harvesting and biomimetic nervous systems.

It is of great significance to establish a low-cost, high-efficiency, self-powered micrometeorological monitoring system for agriculture, animal husbandry, and transportation. However, each additional detection element in the meteorological monitoring system increases the power consumption of the whole system by about 0.7 W. As a renewable energy technology, a triboelectric nanogenerator has the advantages of low price and self-powered sensing. To reduce the power consumption of the micrometeorological monitoring system, this work introduces an innovative solution: the wind-gathering enhanced triboelectric-electromagnetic hybrid generator (WGE-TEHG). Coupling the thin-film vibrating triboelectric nanogenerator (TENG) and electromagnetic generator (EMG), the TENG is used to monitor wind direction and the EMG is used to monitor wind speed and provide energy needed by the system. In particular, the TENG can be used as a self-powered sensor to reduce the power consumption of the sensing system. Besides, the TENG is used to produce slit effect to enhance the output performance of EMG. The experimental results show that the WGE-TEHG can build a self-powered natural environment micrometeorological sensing system. It can monitor the wind direction, wind speed, temperature, and relative humidity. This research has great application value for the self-powered sensing implementation of a hybrid TENG and EMG.

The global annual vegetable and fruit waste accounts for more than one-fifth of food waste, mainly due to deterioration. In addition, agricultural product spoilage can produce foodborne illnesses and threaten public health. Eco-friendly preservation technologies for extending the shelf life of agricultural products are of great significance to socio-economic development. Here, we report a dual-functional TENG (DF-TENG) that can simultaneously prolong the storage period of vegetables and realize wireless storage condition monitoring by harvesting the rotational energy. Under the illumination of the self-powered high-voltage electric field, the deterioration of vegetables can be effectively slowed down. It can not only decrease the respiration rate and weight loss of pakchoi but also increase the chlorophyll levels (∼33.1%) and superoxide dismutase activity (∼11.1%) after preservation for 4 days. Meanwhile, by harvesting the rotational energy, the DF-TENG can be used to drive wireless sensors for monitoring the storage conditions and location information of vegetables during transportation in real time. This work provides a new direction for self-powered systems in cost-effective and eco-friendly agricultural product preservation, which may have far-reaching significance to the construction of a sustainable society for reducing food waste.

Chemical analysis of ions and small organic molecules in liquid samples is crucial for applications in chemistry, biology, environmental sciences, and health monitoring. Mainstream electrochemical and chromatographic techniques often suffer from complex and lengthy sample preparation and testing procedures and require either bulky or expensive instrumentation. Here, we combine triboelectrification and charge transfer on the surface of electrical insulators to demonstrate the concept of triboelectric spectroscopy (TES) for chemical analysis. As a drop of the liquid sample slides along an insulating reclined plane, the local triboelectrification of the surface is recorded, and the charge pattern along the sample trajectory is used to build a fingerprinting of the charge transfer spectroscopy. Chemical information extracted from the charge transfer pattern enables a new nondestructive and ultrafast (<1 s) tool for chemical analysis. TES profiles are unique, and through an automated identification, it is possible to match against standard and hence detect over 30 types of common salts, acids, bases and organic molecules. The qualitative and quantitative accuracies of the TES methodology is close to 93%, and the detection limit is as low as ppb levels. Instruments for TES chemical analysis are portable and can be further miniaturized, opening a path to in situ and rapid chemical detection relying on inexpensive, portable low-tech instrumentation.

The monitoring of space debris assumes paramount significance to ensure the sustainability and security of space activities as well as underground bases in outer space. However, designing a wide range monitoring system with easy fabrication, low power, and high precision remains an urgent challenge under the scarcity of materials and extreme environment conditions of outer space. Here, we designed a one-piece, robust, but flexible, and repairable 3D metal-printed triboelectric nanogenerator (FR-TENG) by incorporating the advantages of standardization and customization of outer space 3D metal printing. Inspired by the structure of hexagonal and pangolin scales, a curved structure is ingeniously applied in the design of 3D printed metal to adapt different curved surfaces while maintaining superior compressive strength, providing excellent flexibility and shape adaptability. Benefiting from the unique structural design, the FR-TENG has a minimum length of 1 cm with a weight of only 3.5 g and the minimum weight resolution detected of 9.6 g, with a response time of 20 ms. Furthermore, a multichannel self-powered collision monitoring system has been developed to monitor minor collisions, providing warnings to determine potential impacts on the space station and bases surfaces. The system may contribute to ensuring the successful completion of space missions and providing a safer space environment for the exploration of extraterrestrial life and the establishment of underground protective bases.

To mimic natural photonic crystals having color regulation capacities dynamically responsive to the surrounding environment, periodic assembly structures have been widely constructed with response materials. Beyond monocomponent materials with stimulus responses, binary and multiphase systems generally offer extended color space and complex functionality. Constructing a rule for predicting response sensitivity can provide great benefits for the tailored design of intelligently responsive photonic materials. Here, we elucidate mathematical relationships between the response sensitivity of dynamically structural-color changes and the location distances of photonic co-phases in three-dimensional Hansen space that can empirically express the strength of their interaction forces, including dispersion force, polarity force, and hydrogen bonding. Such an empirical rule is proven to be applicable for some typical alcohols, acetone, and acetic acid regardless of their molecular structures, as verified by angle resolution spectroscopy, in situ infrared spectroscopy, and molecular simulation. The theoretical method we demonstrate provides rational access to custom-designed responsive structural coloration.

With the advancements in materials science and micro/nanoengineering, the field of wearable electronics has experienced a rapid growth and significantly impacted and transformed various aspects of daily human life. These devices enable individuals to conveniently access health assessments without visiting hospitals and provide continuous, detailed monitoring to create comprehensive health data sets for physicians to analyze and diagnose. Nonetheless, several challenges continue to hinder the practical application of wearable electronics, such as skin compliance, biocompatibility, stability, and power supply. In this review, we address the power supply issue and examine recent innovative self-powered technologies for wearable electronics. Specifically, we explore self-powered sensors and self-powered systems, the two primary strategies employed in this field. The former emphasizes the integration of nanogenerator devices as sensing units, thereby reducing overall system power consumption, while the latter focuses on utilizing nanogenerator devices as power sources to drive the entire sensing system. Finally, we present the future challenges and perspectives for self-powered wearable electronics.

The development of advanced electrical equipment necessitates polymer dielectrics with a higher electric strength. Unfortunately, this bottleneck problem has yet to be solved because current material modification methods do not allow direct control of deep traps. Here, we propose a method for directly passivating deep traps. Measurements of nanoscale microregion charge characteristics and trap parameters reveal a significant reduction in the number of deep traps. The resulting polymer dielectric has an impressively high electrical strength, less surface charge accumulation, and a significantly increased flashover voltage and breakdown strength. In addition, the energy storage density is increased without sacrificing the charge-discharge efficiency. This reveals a new approach to increasing the energy storage density by reducing the trap energy levels at the electrode-dielectric interface. We further calculated and analyzed the microscopic physical mechanism of deep trap passivation based on density functional theory and characterized the contributions of orbital composition and orbital hybridization.

In this protocol, a copper-catalyzed desymmetric protosilylation of prochiral diynes was developed. The corresponding products were obtained in moderate to high yields and enantiomeric ratios. This approach provides a simple method for synthesizing functionalized chiral tertiary alcohols in the presence of a chiral pyridine-bisimidazoline (Pybim) ligand.

Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing. Significant experimental and theoretical efforts have been achieved toward understanding fundamental behaviors and a wide range of demonstrations since its report in 2012. As a result, considerable technological advancement has been exhibited and it advances the timeline of achievement in the proposed roadmap. Now, the technology has reached the stage of prototype development with verification of performance beyond the lab scale environment toward its commercialization. In this review, distinguished authors in the world worked together to summarize the state of the art in theory, materials, devices, systems, circuits, and applications in TENG fields. The great research achievements of researchers in this field around the world over the past decade are expected to play a major role in coming to fruition of unexpectedly accelerated technological advances over the next decade.

Aerogels, due to their unique interconnected 3D networks, and large number of air-filled pores, extend the structural characteristics and physicochemical properties of the nanoscale to the macro level. However, aerogels made from a single component can hardly meet the needs of multifunctional energy harvesting/supply situations. Here, a BaTiO 3 -based hybrid aerogel (BTO HA) with 3D network structure was prepared. When the BTO HA is used as the electrode of triboelectric nanogenerator (BTO HA-TENG), high electrical output performances were obtained, which is due to the synergistic effect of solid-solid contact electrifications between the two electrification layers, the gas-solid contact electrifications between the inner surface of BTO HA and the air filled in the aerogel pores, and the piezoelectricity of the doped BaTiO 3 nanoparticles. The BTO HA-TENG exhibited excellent fatigue resistance and structural stability after 12,000 cycles of alternatively contact/separation tests, and it can not only provide stable power supply for commercial capacitors, drive small mobile electronic devices but also can be used as a self-powered sensor to monitor human motion signals. Compared with traditional TENGs depending on surface charge transfer, the BTO HA-TENG exhibited its unique advantage that it can generate and transfer triboelectric charges by 3D volume, which boost TENGs' electrical output performances.

We report copper-catalyzed borylation and silylation of dichlorocyclobutenones, which furnish the boron-substituted and silicon - substituted polyfunctionalized cyclobutenones in high yields. The reactions proceed under mild reaction conditions, show broad substrate scope, and display high chemoselectivity. In addition, a series of transformations of the corresponding products has been realized.

Memristors that emulate synaptic plasticity are building blocks for opening a new era of energy-efficient neuromorphic computing architecture, which will overcome the limitation of the von Neumann bottleneck. Layered two-dimensional (2D) Bi 2 O 2 Se, as an emerging material for next-generation electronics, is of great significance in improving the efficiency and performance of memristive devices. Herein, high-quality Bi 2 O 2 Se nanosheets are grown by configuring mica substrates face-down on the Bi 2 O 2 Se powder. Then, bipolar Bi 2 O 2 Se memristors are fabricated with excellent performance including ultrafast switching speed (<5 ns) and low-power consumption (<3.02 pJ). Moreover, synaptic plasticity, such as long-term potentiation/depression (LTP/LTD), paired-pulse facilitation (PPF), and spike-timing-dependent plasticity (STDP), are demonstrated in the Bi 2 O 2 Se memristor. Furthermore, MNIST recognition with simulated artificial neural networks (ANN) based on conductance modification could reach a high accuracy of 91%. Notably, the 2D Bi 2 O 2 Se enables the memristor to possess ultrafast and low-power attributes, showing great potential in neuromorphic computing applications.

With the development of science and technology, human-machine interaction has brought great benefits to the society. Here, we design a voice and gesture signal translator (VGST), which can translate natural actions into electrical signals and realize efficient communication in human-machine interface. By spraying silk protein on the copper of the device, the VGST can achieve improved output and a wide frequency response of 20-2000 Hz with a high sensitivity of 167 mV/dB, and the resolution of frequency detection can reach 0.1 Hz. By designing its internal structure, its resonant frequency and output voltage can be adjusted. The VGST can be used as a high-fidelity platform to effectively recover recorded music and can also be combined with machine learning algorithms to realize the function of speech recognition with a high accuracy rate of 97%. It also has good antinoise performance to recognize speech correctly even in noisy environments. Meanwhile, in gesture recognition, the triboelectric translator is able to recognize simple hand gestures and to judge the distance between hand and the VGST based on the principle of electrostatic induction. This work demonstrates that triboelectric nanogenerator (TENG) technology can have great application prospects and significant advantages in human-machine interaction and high-fidelity platforms.

An anterior cruciate ligament (ACL) tear is a common musculoskeletal injury with a high incidence. Traditional diagnosis employs magnetic response imaging (MRI), physical testing, or other clinical examination, which relies on complex and expensive medical instruments, or individual doctoral experience. Herein, we propose a wearable displacement sensing system based on a grating-structured triboelectric stretch sensor to diagnose the ACL injuries. The stretch sensor exhibits a high resolution (0.2 mm) and outstanding robustness (over 1,000,000 continuous operation cycles). This system is employed in clinical trial to diagnose ACL injuries. It measures the displacement difference between the affected leg and the healthy leg during Lachman test. And when such a difference is greater than 3 mm, the ACL is considered to be at risk for injury or tear. Compared with the gold standard of arthroscopy, the consistency rate of this wearable diagnostic system reached about 85.7%, which is higher than that of the Kneelax3 arthrometer (78.6%) with a large volume. This shows that the wearable system possesses the feasibility to supplement and improve existing arthrometers for facile diagnosing ACL injuries. It may take a promising step for wearable healthcare.

Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.

Patients with diabetes have 15-25% chance for developing diabetic ulcers as a severe complication and formidable challenge for clinicians. Conventional treatment for diabetic ulcers is to surgically remove the necrotic skin, clean the wound, and cover it with skin flaps. However, skin flap often has a limited efficacy, and its acquisition requires a second surgery, which may bring additional risk for the patient. Skin tissue engineering has brought a new solution for diabetic ulcers. Herein, we have developed a bioactive patch through a compound culture and the optimized decellularization strategy. The patch was prepared from porcine small intestinal submucosa (SIS) and modified by an extracellular matrix (ECM) derived from urine-derived stem cells (USCs), which have low immunogenicity while retaining cytokines for angiogenesis and tissue regeneration. The protocol included the optimization of the decellularization time and the establishment of the methods. Furthermore, the in vitro mechanism of wound healing ability of the patch was investigated, and its feasibility for skin wound healing was assessed through an antishrinkage full-thickness skin defect model in type I diabetic rats. As shown, the patch displayed comparable effectiveness to the USCs-loaded SIS. Our findings suggested that this optimized decellularization protocol may provide a strategy for cell-loaded scaffolds that require the removal of cellular material while retaining sufficient bioactive components in the ECM for further applications.

Controlled polymerization of cumulenic monomers represents a promising yet underdeveloped strategy toward well-defined alkyne polymers. Here we report a stereoelectronic effect-inspired approach using simple vinylidenecyclopropanes (VDCPs) as butatriene homologues in controlled radical ring-opening polymerizations. While being thermally stable, VDCPs mimic butatrienes via conjugation of the cyclopropane ring. This leads to exclusive terminal-selective propagation that affords a highly structurally regular alkyne-based backbone, featuring complete ring-opening and no backbiting regardless of polymerization conditions.

Contact between water droplets with hydrophobic surfaces is a common phenomenon at functional interfaces, and it has been extensively studied. However, quantifying the charge transfer between the liquid-solid interfacial contacting, especially for the charge density distribution throughout the movement of liquid droplet on a dielectric surface, remains to be investigated. Here, we developed a pixeled droplet triboelectric nanogenerator (pixeled droplet-TENG) array with high-density electrode array as a probe for measuring the charge transfer at a liquid-solid interface when a water drop moves on the hydrophobic surface. To intuitively observe the charge transfer between the liquid-solid interface, we "imaged" the transferred charges along movement trajectory of a water droplet as it slides along a tilted solid surface at a spatial resolution of 0.4 mm and time sensitivity of 0.02 s. Our study shows that the transferred charges are not uniformly distributed along the path, which is possibly due to the two-step model of electron transfer and ion adsorbed on the solid surface, and thus the formation of an electric double layer will inevitably shield the net surface on the solid surface. Our study presents a probe technology with potential applications in surface chemistry, physics, material science, and cell biology.

The application scope of metal-organic frameworks (MOFs) can be extended by rationally designing the architecture and components of MOFs, which can be achieved via a metal-containing solid templated strategy. However, this strategy suffers from low efficiency and provides only one specific MOF from one template. Herein, we present a versatile templated strategy in which organic ligands are weaved into hydrogen-bonded organic frameworks (HOFs) for the controllable and scalable synthesis of MOF nanotubes. HOF nanowires assembled from benzene-1,3,5-tricarboxylic acid and melamine via a simple sonochemical approach serve as both the template and precursor to produce MOF nanotubes with varied metal compositions. Hybrid nanotubes containing nanometal crystals and N-doped graphene prepared through a carbonization process show that the optimized NiRuIr alloy@NG nanotube exhibits excellent electrocatalytic HER activity and durability in alkaline media, outperforming most reported catalysts. The strategy proposed here demonstrates a pioneering study of combination of HOF and MOF, which shows great potential in the design of other nanosized MOFs with various architectures and compositions for potential applications.

Tribovoltaic nanogenerators (TVNGs) are an emerging class of devices for high-entropy energy conversion and mechanical sensing that benefit from their outstanding real-time direct current output characteristics. Here, a self-powered TVNG was fabricated using a small-area 4H-SiC semiconductor wafer and a large-area copper foil. Thus, the cost of materials remains low compared to devices employing large-scale semiconductors. The 4H-SiC/metal-TVNGs (SM-TVNGs) presented here are sensitive to vertical force and sliding velocity, making them appropriate for mechanical sensing. Notably, owing to the modulated bindingtons and surface states, these SM-TVNGs performed well in a harsh environment, namely, in high-temperature and high-humidity conditions. In addition, the SM-TVNGs exhibited an excellent wear-resisting property. On these bases, we designed a self-powered and real-time monitoring device able to estimate the number of staff present in various areas of a deep mining site, a high-temperature and high-humidity environment. This work not only discloses basic physics behind the tribovoltaic effect but also sheds light on possible applications of SM-TVNGs for wear-resisting and stable mechanical sensors in harsh environments.

Tribovoltaic direct-current (DC) nanogenerator made of dynamic semiconductor heterojunction is emerging as a promising mechanical energy harvesting technology. However, fundamental understanding of the mechano-electronic carrier excitation and transport at dynamic semiconductor interfaces remains to be investigated. Here, we demonstrated for the first time, that tribovoltaic DC effect can be tuned with metal - insulator transition (MIT). In a representative MIT material (vanadium dioxide, VO 2 ), we found that the short-circuit current ( I SC ) can be enhanced by >20 times when the material is transformed from insulating to metallic state upon static or dynamic heating, while the open-circuit voltage ( V OC ) turns out to be unaffected. Such phenomenon may be understood by the Hubbard model for Mott insulator: orders' magnitude increase in conductivity is induced when the nearest hopping changes dramatically and overcomes the Coulomb repulsion, while the Coulomb repulsion giving rise to the quasi-particle excitation energy remains relatively stable.

Triboelectric potential gated transistors have inspired various applications toward mechanical behavior controlled logic circuits, multifunctional sensors, artificial sensory neurons, etc . Their rapid development urgently calls for high-performance devices and corresponding figure of merits to standardize the tribotronic gating properties. Organic semiconductors paired with solution processability promise low-cost manufacture of high-performance tribotronic transistor devices/arrays. Here, we demonstrate a record high-performance tribotronic transistor array composed of an integrated triboelectric nanogenerator (TENG) and a large-area device array of C8-BTBT-PS transistors. The working mechanism of effective triboelectric potential gating is elaborately explained from the aspect of conjugated energy bands of the contact-electrification mediums and organic semiconductors. Driven by the triboelectric potential, the tribotronic transistor shows superior properties of record high current on/off ratios (>10 8 ), a steep subthreshold swing (29.89 μm/dec), high stability, and excellent reproducibility. Moreover, tribotronic logic devices modulated by mechanical displacement have also been demonstrated with good stability and a high gain of 1260 V/mm. The demonstrated large-area tribotronic transistor array of organic semiconductor exhibits record high performance and offers an effective R&D platform for mechano-driven electronic terminals, interactive intelligent system, artificial robotic skin, etc .

Water splitting for yielding high-purity hydrogen represents the ultimate choice to reduce carbon dioxide emission owing to the superior energy density and zero-pollution emission after combustion. However, the high electricity consumption and requirement of large quantities of pure water impede its large-scale application. Here, a triboelectric nanogenerator (W-TENG) converting offshore wind energy into electricity is proposed for commercial electric energy saving and cost reduction. By introducing PTFE/POM dielectric pairs with matched HOMO/LUMO band gap energy, a high charge density is achieved to promote the output of W-TENG. With the impedance matching design of transformers with the internal resistance of W-TENG, the output current is further enhanced from 1.42 mA to 54.5 mA with a conversion efficiency of more than 92.0%. Furthermore, benefiting from the high electrocatalytic activity (overpotential = 166 mV and Tafel slope = 181.2 mV dec -1 ) of a carbon paper supported NiCoP-MOF catalyst, natural seawater can be adopted as a resource for in situ hydrogen production without acid or alkaline additives. Therefore, the self-powered seawater electrolysis system achieves a H 2 production rate as high as 1273.9 μL min -1 m -2 with a conversion efficiency of 78.9%, demonstrating a more practical strategy for conversion of wind energy into renewable hydrogen energy.

We report here an efficient and highly diastereoselective intermolecular anti-Markovnikov hydroamination of unactivated alkenes with aliphatic azides in the presence of silane. The system tolerates a wide range of azides and alkenes and operates with alkene as limiting reagent. Mechanistic studies suggest a radical chain pathway that involves aminium radical formation, radical addition to alkenes and HAT from silane to β-aminium alkyl radical. The use of sterically bulky silane is proposed to contribute to the excellent diastereoselectivity for HAT. Computational analysis uncovers the reaction pathway of aliphatic azide activation with silyl radical for aminyl radical formation.

The forthcoming wearable health care devices garner considerable attention because of their potential for monitoring, treatment, and protection applications. Herein, a self-powered triboelectric patch was developed using polytetrafluoroethylene rubbed with nylon fabric. The triboelectric patch can maintain a stable electrostatic field, due to the excess electrification on the surface of the triboelectric layer. The designed triboelectric nanogenerator (TENG) output watt density can reach about 485 mW/m 2 with added resistance of 11 kΩ. Additionally, the performance of the triboelectric patch allowed eye movement monitoring. The maximum voltage could reach 80 V at the vertical distance of 20 mm between the frictional layer and collector. The triboelectric patch not only can power a digital watch for potential wearable applications but also can be integrated to monitor eye movements during sleep. This work proposed a mechanism for human movement energy harvesting, which may be used for self-powered smart wearable health equipment and Maxwell displacement current wireless sensors.

Implantable sensors with the abilities of real-time healthcare monitoring and auxiliary training are important for exercise-induced or disease-induced muscle and ligament injuries. However, some of these implantable sensors have some shortcomings, such as requiring an external power supply or poor flexibility and stability. Herein, an organogel/silicone fiber-helical sensor based on a triboelectric nanogenerator (OFS-TENG) is developed for power-free and sutureable implantation ligament strain monitoring. The OFS-TENG with high stability and ultrastretchability is composed of an organogel fiber and a silicone fiber intertwined with a double helix structure. The organogel fiber possesses the merits of rapid preparation (15 s), good transparency (>95%), high stretchability (600%), and favorable stability (over 6 months). The OFS-TENG is successfully implanted on the patellar ligament of the rabbit knee for the real-time monitoring of knee ligament stretch and muscle stress, which is expected to provide a solution for real-time diagnosis of muscle and ligament injuries. The prepared self-powered OFS-TENG can monitor data on human muscles and ligaments in real-time.

Vibration is an omnipresent energy source that is renewable and has the potential to cause damage to transmission lines. Harvesting harmful vibration energy can achieve vibration attenuation. Here, a vibration-driven triboelectric nanogenerator (V-TENG) with the potential for vibration attenuation is proposed as a power source for monitoring the operating condition of transmission lines. The V-TENG with structural optimization and frequency response range improvement is first discussed, indicating that it has a simple structural design with a good output performance. Then an energy management circuit is used to improve the charging efficiency of large capacitors. The vibration attenuation effect and wireless transmission system are verified in the simulation environment, benefiting from the well-designed structure and outstanding electric performance. This work demonstrates an efficient strategy for harvesting vibration energy through the TENG, which provides valuable guidance for further construction of online monitoring of transmission lines.

Photonic materials that enable visual detection of chemicals have shown great potential for wide applications in chemical, environmental, biotechnological, and food industries, but until now, using hydrophilic photonic materials for tracing water-soluble chemicals remains a major challenge due to the strong water interference. Here, we demonstrate a two-step co-assembly and subsequent surface coating strategy to develop an ethanol-sensitive and anti-water interference photonic crystal film. By using citric acid as a co-assembly phase, high ethanol sensing is realized because of the strong intermolecular affinity. By controlling the thickness of the outer polyvinyl butyral layer, selective ethanol penetration but a water barrier is enabled. Notably, the composite photonic films are free-standing, highly flexible, and controllably structurally colored. We further present using the composite film to quantitatively trace ethanol/water mixtures and potentially track drunk driving as a colorimetric sensor. The heuristic two-step modification strategy proposed in this work not only overcomes the limitation of water interference for hydrophilic colorimetric sensors but also provides references to develop more new photonic materials with water resistance that need to be applied in water/humid environments.

Ultrasound (US)-triggered sonodynamic therapy (SDT) based on semiconductor nanomaterials has attracted considerable attention for cancer therapy. However, most inorganic sonosensitizers suffer from low efficiency due to the rapid recombination of electron-hole pairs. Herein, the Cu 2- x O-BaTiO 3 piezoelectric heterostructure was fabricated as a sonosensitizer and chemodynamic agent, simultaneously, for improving reactive oxygen species (ROS) generation and cancer therapeutic outcome. Under US irradiation, the Cu 2- x O-BaTiO 3 heterojunction with a piezotronic effect exhibits high-performance singlet oxygen ( 1 O 2 ) and hydroxyl radical (•OH) generation to enhance SDT. Moreover, it possesses Fenton-like reaction activity to convert endogenous H 2 O 2 into •OH for chemodynamic therapy (CDT). The integration of SDT and CDT substantially boosts ROS generation and cellular mitochondria damage, and the in vitro and in vivo results demonstrate high cytotoxicity and tumor inhibition on murine refractory breast cancer. This work realizes improvement in cancer therapy using piezoelectric heterostructures with piezotronic effects.

A copper-catalyzed regioselective Markovnikov 3,4-hydrosilylation of 2-substituted 1,3-dienes has been accomplished. A wide range of 2-substituted 1,3-dienes and trihydrosilanes are compatible under the optimal conditions. The bisphosphine ligand with a rigid backbone provides the Markovnikov 3,4-hydrosilylation product in better yield and selectivity. Besides, the synthetic utilities of the allylsilanes also were demonstrated by their flexible derivatizations.

A stretchable triboelectric nanogenerator (TENG) can be a promising solution for the power supply of various flexible electronics. However, the detailed electrification mechanism of elastic triboelectric materials still needs to be clarified. In this work, we found crystallization behavior induced by strain and low temperature can lead to a shift in a triboelectric series for commonly used triboelectric elastomers and even reverse the triboelectric polarity. This effect is attributed to the notable rearrangement of surface electron cloud density happening along with the crystallization process of the molecular chain. This effect is significant with natural rubber, and silicone rubber can experience this effect at low temperature, which also leads to a shift in a triboelectric series, and an applied strain at low temperature can further enhance this shift. This study demonstrated that the electrification polarity of triboelectric materials should be re-evaluated under different strains and different temperatures, which provides a mechanism distinct from the general understanding of elastic triboelectric materials.

Sleep quality plays an essential role in human health and has become an index for assessing physical health. Self-powered, sensitive, noninvasive, comfortable, and low-cost sleep monitoring sensors for monitoring sleep behavior are still in high demand. Here, a pressure-sensitive, noninvasive, and comfortable smart pillow is developed based on a flexible and breathable triboelectric nanogenerator (FB-TENG) sensor array, which can monitor head movement in real time during sleep. The FB-TENG is based on flexible and breathable porous poly(dimethylsiloxane) (PDMS) with a fluorinated ethylene propylene (FEP) powder and exhibits pressure sensitivity and durability. The electrical output of the FB-TENG is further optimized by modifying the porous structure and the FEP powder. Combining the FB-TENG and the flexible printed circuit (FPC), a self-powered pressure sensor array is fabricated to realize touch sensing and motion track monitoring. The smart pillow is formed by laying the self-powered pressure sensor array on an ordinary pillow to realize real-time monitoring of the head position in a static state and head movement trajectory in a dynamic state during sleep. Additionally, the smart pillow also has an early warning function for falling out of bed. This work not only provides a viable sensing device for sleep monitoring but also could be extended to real-time monitoring of some diseases, such as brain diseases and cervical spondylosis, in the future. It is expected to introduce a practical strategy in the real-time mobile healthcare field for disease management.

The triboelectric nanogenerator shows a broad application potential in wind energy collection and wind speed sensing. However, it is difficult to realize wind energy collection and real-time wind speed monitoring in one simple device without external power support. Here, a high-performance dual-mode triboelectric nanogenerator is proposed to simultaneously collect wind energy efficiently and monitor wind speed in real time, which is composed by an alternating current triboelectric nanogenerator (AC-TENG) and a direct-current triboelectric nanogenerator (DC-TENG). Based on the material optimization, the charge density of the AC-TENG improves by a factor of 1 compared with previous works. Moreover, benefiting from the elastic structure and material optimization to realize a low friction force, the AC-TENG shows an excellent durability and obtains a retention of 87% electric output after 1 200 000 operation cycles. Meanwhile, thanks to the high charge density and low friction force, the energy-harvesting efficiency of the AC-TENG is doubled. In addition, the DC-TENG not only displays an excellent real-time sensing performance but also can provide gale warning. Our finding exhibits a strategy for efficiently collecting wind energy and achieving fully self-powered and real-time wind speed monitoring.

Wave motion in the ocean can generate plentiful energy, but it is difficult to harvest wave energy for practical use because of the low frequency and random directional characteristics of wave motion. In this paper, a gyroscope-structured triboelectric nanogenerator (GS-TENG) is proposed for harvesting multidirectional ocean wave energy. Its inner and outer generation units can operate independently in different directions, and they all adopt the friction mode of surface contact. While realizing noninterference multidirectional energy harvesting, the power generation area is increased. In the experiments, under acceleration of 6 m/s 2 with variations in excitation angle, the GS-TENG can output direct currents of 0.8-3.2 μA, and the open-circuit voltages of the inner and outer generation units can reach 730 and 160 V, respectively. When the devices are networked and placed in the water, the electrical energy generated by the GS-TENGs can enable commercial thermometers to operate normally. The attenuation of direct-current output by the GS-TENG in the experiment of 30 days in water is about 8%, which verifies the good durability of the device in the water environment. Therefore, the GS-TENG has excellent application prospects in the wave energy harvesting field.