Moisture‑Electric–Moisture‑Sensitive Heterostructure Triggered Proton Hopping for Quality‑Enhancing Moist‑Electric Generator

Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.

Laser fabrication of functional micro-supercapacitors

Due to the rapid development of portable,wearable and implantable electronics in the fields of mobile communications,biomonitoring,and aerospace or defense,there is an increasing demand for miniaturized and lightweight energy storage devices.Micro-supercapacitors(MSCs)possessing long lifetime,high power density,environment friendliness and safety,have attracted great attention recently.Since the performance of the MSCs is mainly related to the structure of the active electrode,there is a great need to explore the efficient fabricating strategies to deterministically coordinate the structure and functionality of microdevices.Considering that laser technology possesses many superior features of facility,high-precision,low-cost,high-efficiency,shape-adaptability and maneuverability,herein we summarize the development of laser technologies in MSCs manufacturing,along with their strengths and weaknesses.The current achievements and challenges are also highlighted and discussed,aiming to provide a valuable reference for the rational design and manufacture of MSCs in the future.

Two-dimensional materials of group-IVA boosting the development of energy storage and conversion

Graphene,an emerging fabric of carbon atoms,has manifested its versatility in all kinds of fields encompassing electronics,optoelectronics,thermoelectrics,taking advantage of its excellent mechanical strength,exceptional electronic and thermal conductivities,high surface specific area,and so forth.The prosperity of graphene never seen before has led the attention to silicene,siloxene,germanene,stanene,and plumbene due to their promising applications in the quantum spin Hall effect,topological insulator,batteries,capacitors,catalysis,and topological superconductivity.Herein,we review the existing production methods,numerous applications of two-dimensional group-IVA materials,and critically discuss the challenges of these materials,providing potential implications to the exploration of uncharted material systems.

Few‐layer carbon nitride photocatalysts for solar fuels and chemicals:Current status and prospects

Converting sunlight directly to fuels and chemicals is a great latent capacity for storing renewable energy.Due to the advantages of large surface area,short diffusion paths for electrons,and more exposed active sites,few‐layer carbon nitride(FLCN)materials present great potential for production of solar fuels and chemicals and set off a new wave of research in the last few years.Herein,the recent progress in synthesis and regulation of FLCN‐based photocatalysts,and their applications in the conversion of sunlight into fuels and chemicals,is summarized.More importantly,the regulation strategies from chemical modification to microstructure control toward the production of solar fuels and chemicals has been deeply analyzed,aiming to inspire critical thinking about the effective approaches for photocatalyst modification rather than developing new materials.At the end,the key scientific challenges and some future trend of FLCN‐based materials as advanced photocatalysts are also discussed.

Recent progress and challenges in interdigital microbatteries:Fabrication, functionalization and integration

Currently,the increasing demands for portable,implantable,and wearable electronics have triggered the interest in miniaturized energy storage devices.Different from conventional energy storage devices,interdigital microbatteries(IMBs) are free of separators and prepared on a single substrate,potentially achieving a short ionic diffusion path and better performance.Meanwhile,they can be easily fabricated and integrated into on-chip miniaturized electronics,holding the promise to provide long-lasting power for advanced microelectronic devices.To date,while many seminal works have been reviewed the topic of microbatteries,there is no work that systematically summarizes the development of IMBs of high energy density and stable voltage platforms from fabrication,functionalization to integration.The current review focuses on the most recent progress in IMBs,discussing advanced micromachining techniques with compatible features to construct high-performance IMBs with smart functions and intelligent integrated systems.The future opportunities and challenges of IMBs are also highlighted,calling for more efforts in this dynamic and fast-growing research field.

The Feasible Design of Quasi-Solid-State Aqueous Tin-Iodine Batteries

Aqueous rechargeable batteries with high safety have been considered as the main energy source to power portable and wearable electronics.Herein,we report the first construction of quasi-solid-state aqueous tin-iodine batteries by exploiting Sn foil as anode,carbon cloth as cathode,and gel electrolytes.The anode reversibly converts from K_(2)Sn(OH)_(6) to metal Sn,thus eliminating the formation of metal dendrites.Meanwhile,gel electrolytes alleviate anode corrosion and enhance the utilization of the anode.Therefore,the asfabricated quasi-solid-state batteries manifest an areal capacity of 700μAh cm^(-2)(211 mAh g^(-1) equal to theoretical capacity)and excellent cycling stability without obvious capacity degradation after 120 cycles at 1mA cm^(-2).Remarkably,the designed batteries sealed by different package materials including plastic,glass,wood,and cardboard operated steadily,thereby enlarging the application scenario for these batteries.This work enriches the family of aqueous rechargeable batteries and sheds light on the construction of high-performance quasi-solid-state aqueous batteries.

Promising thermal photonic management materials for sustainable human habitat

The spectral characteristics of outdoor structures,such as automobiles,buildings,and clothing,determine their energy interaction with the environment,from broad-spectrum absorption of light energy to high-efficiency thermal emission.Recently developed spectrally selective absorption(SSA)materials permit the reduction of energy loss from human habitat eco-system in the sustainable way and further reduce the utilization of fossil energy to achieve carbon neutrality.Here we review recent advances in SSA materials that enable rational and efficient management of thermal energy and provide new solutions for the resource base that supports human life like comfortable heat management,electricity production,and water supply.The basic principles of thermal photonic management,the regulation of SSA materials,and functional properties are summarized.An outlook discussing challenges and opportunities in SSA material energy management for comfortable living environments is finally presented,which expects the enormous potential of this interdisciplinary research in solving growing resource-shortage of human society.

A cross-linked polyacrylamide electrolyte with high ionic conductivity for compressible supercapacitors with wide temperature tolerance

The development of compressible supercapacitors (SCs) that is tolerant to wide temperature range has been severely hindered due to the poor ionic conductivity and absence of extra functions in conventional polymer electrolytes.Herein,a highly conductive and compressible hydrogel polyelectrolyte has been prepared from polyacrylamide cross-linked by methacrylated graphene oxide (MGO-PAM) and the polyelectrolyte can maintain its excellent elasticity at-30 ℃ as well as its original shape at 100 ℃.As a result,the SC based on the MGO-PAM polyelectrolyte outperformed those fabricated with the conventional poly(vinyl alcohol)(PVA)/H2SO4 electrolyte over a wide temperature window between-30 and 100 ℃.Meanwhile,the device shows an excellent cycling stability (capacitance retention of 93.3% after 8,000 cycles at-30 ℃ and 76.5 % after 4,000 cycles under 100 ℃) and a reversible compressibility (a high capacitance retention of 94.1% under 80% compression).Therefore,the MGO-PAM polyelectrolyte enables the fabrication of compressible SCs with a wide operating temperature,rendering new insights for developing next-generation robust and multifunctional energy-storage devices.

Ultrafast optical response and ablation mechanisms of molybdenum disulfide under intense femtosecond laser irradiation

Numerous valuable studies on electron dynamics have focussed on the extraordinary properties of molybdenum disulfide(MoS_(2));however,most of them were confined to the level below the damage threshold.Here the electron dynamics of MoS_(2) under intense ultrafast laser irradiation was investigated by experiments and simulations.Two kinds of ablation mechanisms were revealed,which led to two distinct types of electron dynamics and final ablation morphology.At a higher fluence,the emergence of superheated liquid induced a dramatic change in the transient reflectivity and micro-honeycomb structures.At a lower fluence,the material was just removed by sublimation,and the ablation structure was relatively flat.X-ray photoelectron spectroscopic(XPS)measurements demonstrated that thermal decomposition only occurred at the higher fluence.Furthermore,a theoretical model was developed to deeply reveal the ultrafast dynamics of MoS_(2) ablation.The simulation results were in good agreement with the temporal and spatial reflectivity distribution obtained from the experiment.The electron and lattice temperature evolution was also obtained to prove the ablation mechanism.Our results revealed ultrafast dynamics of MoS_(2) above the damage threshold and are helpful for understanding the interaction mechanism between MoS_(2) and intense ultrafast lasers,as well as for MoS_(2) processing applications.

Micro/nano processing of natural silk fibers with near-field enhanced ultrafast laser

Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is still a challenge limiting its applications in nanoengineering and related fields.Herein,we report localized near-field enhancement-assisted ablation with an ultrafast laser to break this bottleneck.Localized processing of silk fiber,including nano-holing,nano-grooving,and cutting could retain the key molecular structure building blocks and the pristine functionality of the silk fiber.An extremely narrow nanohole with a width of^64 nm was successfully achieved.The processed silk fiber can be used to transfer micro/nanoparticles and drugs,showing potential for biomedical engineering.The processing strategy developed in this study can also be extended to other materials,paving a new way for fabricating functional nanostructures with precisely controlled size and morphology.

Nanoscale multi-beam lithography of photonic crystals with ultrafast laser

Photonic crystals are utilized in many noteworthy applications like optical communications,light flow control,and quantum optics.Photonic crystal with nanoscale structure is important for the manipulation of light propagation in visible and near-infrared range.Herein,we propose a novel multi beam lithography method to fabricate photonic crystal with nanoscale structure without cracking.Using multi-beam ultrafast laser processing and etching,parallel channels with subwavelength gap are obtained in yttrium aluminum garnet crystal.Combining optical simulation based on Debye diffraction,we experimentally show the gap width of parallel channels can be controlled at nanoscale by changing phase holograms.With the superimposed phase hologram designing,functional structures of complicated channel arrays distribution can be created in crystal.Optical gratings of different periods are fabricated,which can diffract incident light in particular ways.This approach can efficiently manufacture nanostructures with controllable gap,and offer an alternative to the fabrication of complex photonic crystal for integrated photonics applications.

Recent progress in graphene-based electrodes for flexible batteries

The emerging flexible electronic devices have stimulated the development of flexible batteries,in which flexible electrodes are indispensable components.Graphene,known for its excellent electrical conductivity and mechanical stability,can be used as an ideal flexible substrate.Recently,many efforts have been devoted to graphene-based electrodes for flexible batteries.Herein,this review summarizes recent advances in the development of graphene-based electrodes for various flexible batteries,including metal-ion batteries(ions of Li,Na,Zn,Al,etc.),lithiumsulfur batteries,and metal-air batteries(Li-and Zn-air batteries).Besides,major challenges and future developments of flexible batteries are also discussed.

Hybrid superhydrophilic-superhydrophobic micro/nanostructures fabricated by femtosecond laserinduced forward transfer for sub-femtomolar Raman detection

Raman spectroscopy plays a crucial role in biochemical analysis.Recently,superhydrophobic surface-enhanced Raman scattering(SERS)substrates have enhanced detection limits by concentrating target molecules into small areas.However,due to the wet transition phenomenon,further reduction of the droplet contact area is prevented,and the detection limit is restricted.This paper proposes a simple method involving femtosecond laser-induced forward transfer for preparing a hybrid superhydrophilic–superhydrophobic SERS(HS-SERS)substrate by introducing a superhydrophilic pattern to promote the target molecules to concentrate on it for ultratrace detection.Furthermore,the HS-SERS substrate is heated to promote a smaller concentrated area.The water vapor film formed by the contact of the solution with the substrate overcomes droplet collapse,and the target molecules are completely concentrated into the superhydrophilic region without loss during evaporation.Finally,the concentrated region is successfully reduced,and the detection limit is enhanced.The HS-SERS substrate achieved a final contact area of 0.013mm2,a 12.1-fold decrease from the unheated case.The reduction of the contact area led to a detection limit concentration as low as 10−16 M for a Rhodamine 6G solution.In addition,the HS-SERS substrate accurately controlled the size of the concentrated areas through the superhydrophilic pattern,which can be attributed to the favorable repeatability of the droplet concentration results.In addition,the preparation method is flexible and has the potential for fluid mixing,fluid transport,and biochemical sensors,etc.

Recent advances in highly integrated energy conversion and storage system

The vigorous development in the field of energy conversion and storage devices directly contributes to the full utilization and convenient use of clean energy.However,some drawbacks of independent energy conversion and storage devices,including unstable,insufficient energy output and dependence on external power supply,are difficult to overcome by self-optimization,thus,hindering their further development and direct application.Coincidentally,the combination of above two devices can solve these problems,which conforms to their intrinsic needs for development.At the same time,the pursuit of portability and miniaturization also promotes the development of the power system toward a highly integrated direction.Therefore,we introduce several integration modes of energy conversion and storage systems,with emphasis on all-in-one power system,possessing the highest integration in this review.From the aspect of device configuration,working mechanisms and their performances,the all-inone power systems based on different energy sources(e.g.,mechanical,solar,thermal,and chemical energy)are discussed and analyzed.Finally,the design strategies are summarized and the potential development directions in the future are proposed.This review aims to provide a comprehensive overview of highly integrated energy conversion and storage system,and seeks to point out the opportunities and orientations of future research in this field.

Interface-enhanced distillation beyond tradition based on well-arranged graphene membrane

Traditional distillation(TD)is generally an energy-intensive and inefficient process for separation and purification of liquids in chemical industries.Herein,we developed an interface-enhanced distillation(IED)by employing a well-arranged membrane of reduced graphene oxide(rGO)sheet arrays embedded with silicon dioxide nanofibres(rGO/SiO2)as the evaporation intermediate layer on the liquid surface.This IED enlarges the evaporation surfaces and weakens the intermolecular forces on the liquid/solid/gas interfaces,realizing the fast and even low temperature fraction collection with less energy consumption.The IED delivers evaporation rates 200%–300%times that of TD,meanwhile having an energy saving of 40%–60%and a time saving of 50%–70%for diverse liquid feeds.In atmospheric IED manner,high boiling point and perishable organics can be collected with high quality at a temperature lower than their boiling points.This IED provides an innovative strategy for highly efficient distillation in chemical industries.

An efficient and versatile biopolishing strategy to construct high performance zinc anode

Conventional strategies for highly reversible Zn anodes usually involve complex and time-consuming production processes of current collectors,expensive and toxic electrolyte additives,or the introduction of inactive materials in protective layer.Here,we develop a fast,facile,and environmentally friendly biopolishing method to prepare dendrite-free Zn anodes,which merely involves the simple immersion of Zn foil in a biocompatible cysteine aqueous solution.The ravine structure formed by sulfhydryl etching for 30 min not only increases the electroactive area of Zn anode but also regulates the distribution of electric field and Zn ions,ensuring the homogeneous deposition and stripping of Zn ions.The biopolished Zn anode can be operated steadily for 2,000 h with a low voltage hysteresis at a current density of 1 mA·cm^(−2).In addition,Zn anodes with a cycle life of 500 h can be built by soaking for only 5 min,proving the high efficiency of the proposed method.This strategy is generalized to substances with sulfhydryl groups for polishing Zn electrodes with improved performance.The cysteine-polished Zn//activated carbon supercapacitor can stably run for 20,000 cycles without obvious capacity attenuation.The proposed strategy shows potential for producing advanced Zn anodes.

One-step synthesis of hierarchical Ni_(3)Se_(2)nanosheet-on-nanorods/Ni foam electrodes for hybrid supercapacitors

Transitional metal selenides have high conductivity,even metal quality,which makes them great for using as electrode materials for fabricating supercapacitors.Here,hierarchical Ni_(3)Se_(2)nanosheet-on-nanorods on Ni foam(NSR-Ni_(3)Se_(2)/Ni)was fabricated by a facile three-dimensional(3D)substrate-assisted confinement assembly method,and used as a freestanding electrode material for hybrid supercapacitors(HSCs).In this design,metallic Ni_(3)Se_(2)with hybrid 1D/2D architecture could effectively enhance the active specific surface area of electrode and improve space utilization,as well as significantly facilitate electrons transport,while Ni foam served as the Ni source of Ni_(3)Se_(2)and provided 3D multi-electron transport channels,thus boosting the specific capacity.The constructed hierarchical NSR-Ni_(3)Se_(2)electrode delivered a superior areal specific capacity of 1.068 mAh/cm^(2)(7.69 F/cm^(2))at 2 mA/cm^(2)and retained 68.2%of the initial capacity when the current density increases by 15 times.Furthermore,the as-assembled NSR-Ni_(3)Se_(2)device exhibited an ultrahigh energy density of 56.4 Wh/kg and high power density of 4640.3 W/kg,and a capacity retention of 92.6%even after 6000 cycles.

Preparation of sulfur-doped graphene fibers and their application in flexible fibriform micro-supercapacitors

A novel type of sulfur-doped graphene fibers (S-GFs) were prepared by the hydrothermal strategy, the in situ interfacial polymerization method and the annealing method. Two S-GFs were assembled into an all-solid-state fibriform micro-supercapacitor (micro-SC) that is flexible and has a high specific capacitance (4.55 mF·cm^-2) with the current density of 25.47 pA·cm^-2. The cyclic voltammetry (CV) curve of this micro-SC kept the rectangular shape well even when the scan rate reached 2 V·s^-1. There is a great potential for this type of S-GFs used in flexible wearable electronics.

Recent Development of Integrated Systems of Microsupercapacitors

Development of wearable and portable electronics promotes the miniaturization of energy storage devices.Microsupercapacitor(MSC)featuring in fast charging and discharging rates,long cycle life,and high-power density stands out from miniaturized energy storage devices,particularly for its small size and adjustable structure which is easily processed to integrate with other on-chip electronics.In this review,we systematically analyzed the MSC integration with other electronics from the perspective of structures and functions.At the beginning,we briefly introduced typical MSCs with unique properties.Subsequently,applications and integrations of MSCs with energy-consuming or energy-generating electronics were highlighted.Furthermore,compatible materials and designed structure of the all-in-one device were also depicted.Finally,challenges and future development of MSC-integrated systems were put forward.

Multifunctional devices based on planar microsupercapacitors:Progress and challenges

With the boom of portable,wearable,and implantable smart electronics in the last decade,the demand for multifunctional microscale electrochemical energy storage devices has increased.Owing to their excellent rate performance,high power density,long cycling lifetime,easy fabrication,and integration,multifunctional planar microsupercapacitors(PMSCs)are deemed as one of the ideal micropower sources for next-generation flexible on-chip electronics.Therefore,we offer a comprehensive overview of the recent progress regarding multifunctional devices based on PMSCs,including stretchable,self-healing,stimulus-responsive,thermosensitive,biodegradable,and temperaturetolerant microdevices.We also emphasize the unique applications of multifunctionally integrated PMSCs in the construction of self-powered and sensor-integrated systems in terms of multifunctional operation modes.Finally,the key challenges and future prospects related to these multifunctional devices are discussed to stimulate further research in this flourishing field.