Layered double hydroxides (LDHs) are ionic layered compounds characterized by anion-containing intermediate regions within positively charged brucite-like layers. LDHs have shown high electrochemical activity in energy conversion systems such as batteries and fuel cells. In this study, we developed a hierarchically porous nanostructure derived from zeolitic imidazolate framework-67, which was subsequently transformed into an LDH structure with varying Ni concentrations. We precisely controlled the Ni-to-Co ratio within the LDH structure and investigated how different mole fractions of Co and Ni influence catalytic activity and selectivity for the electrochemical urea oxidation reaction (UOR). LDH structures with low Ni content (up to 40%) demonstrated high activity and selectivity for O 2 due to their structural instability and the predominant oxygen evolution reaction (OER) originating from ZIF-67. In contrast, LDHs with high Ni content (over 60%) supressed OER and exhibited enhanced activity for UOR. The resulting hollow structure with an expanded electrochemically active surface in LDHs with high Ni content could improve mass transport and diffusion at the electrode interface, leading to better reaction kinetics and higher current densities. These findings provide a foundational design guideline for metal–organic framework-derived nanostructure in UOR.

With triboelectric nanogenerators (TENGs) introduced in 2012, they have emerged in the fields of flexible wearable electronics, portable energy, Internet of Things (IoT), and biomedicine by virtue of their lightweight, high-energy conversion, low cost, and material selectivity. However, as the application areas of TENGs increase, ambient humidity and human movement generate sweat and moisture that can lead to a decrease in output, so exploring how TENGs operate in high humidity environments is critical to their long-term development. In this paper, different strategies are introduced to enhance TENGs in high humidity environments, such as encapsulation, construction of hydrophobic/superhydrophobic surfaces, and hydrogen bonding enhancement, and discuss the applications of humidity-resistant TENGs in fields such as self-powered sensors, energy harvesters, and motions, etc. Finally, we explore the future directions and routes for the development of humidity-resistant TENGs.

Two-dimensional Ruddlesden-Popper (2D RP) layered metal-halide perovskites have garnered increasing attention due to their favorable optoelectronic properties and enhanced stability in comparison to their three-dimensional counterparts. Nevertheless, precise control over the crystal orientation of 2D RP perovskite films remains challenging, primarily due to the intricacies associated with the solvent evaporation process. In this study, we introduce a novel approach known as reverse-cool annealing (RCA) for the fabrication of 2D RP perovskite films. This method involves a sequential annealing process at high and low temperatures for wet perovskite films. The resulting RCA-based perovskite films show the smallest root-mean-square value of 23.1 nm, indicating a minimal surface roughness and a notably compact and smooth surface morphology. The low defect density in these 2D RP perovskite films with exceptional crystallinity suppresses non-radiative recombination, leading to a minimal non-radiative open-circuit voltage loss of 149 mV. Moreover, the average charge lifetime in these films is extended to 56.30 ns, thanks to their preferential growth along the out-of-plane direction. Consequently, the leading 2D RP perovskite solar cell achieves an impressive power conversion efficiency of 17.8% and an open-circuit voltage of 1.21 V. Additionally, the stability of the 2D RP perovskite solar cell, even without encapsulation, exhibits substantial improvement, retaining 97.4% of its initial efficiency after 1000 hours under a nitrogen environment. The RCA strategy presents a promising avenue for advancing the commercial prospects of 2D RP perovskite solar cells.

The development of advanced anode materials for lithium-ion batteries that can provide high specific capacity and stable cycle performance is of paramount importance. This study presents a novel approach for synthesizing molecular-level homogeneous carbon integration to porous SiO2 nanoparticles (SiO2@C NPs) tailored to enhance their electrochemical activities for lithium-ion battery anode. By varying the ratio of the precursors for sol-gel reaction of (phenyltrimethoxysilane (PTMS) and tetraethoxysilane (TEOS)), the carbon content and porosity within SiO2@C NPs is precisely controlled. With a 4:6 PTMS and TEOS ratio, the SiO2@C NPs exhibit a highly mesoporous structure with thin carbon and the partially reduced SiOx phases, which balances ion and charge transfer for electrochemical activation of SiO2@C NPs resulting remarkable capacity and cycle performance. This study offers a novel strategy for preparing affordable high capacity SiO2-based advanced anode materials with enhanced electrochemical performances.

Sedentary, inadequate sleep and exercise can affect human health. Artificial intelligence (AI) and Internet of thing (IoT) creates the Artificial Intelligence of Things (AIoT), providing the possibility to solve these problems. This paper presents a novel approach to monitor various human behaviors for AIoT-based health management using triboelectric nanogenerator (TENG) sensors. The insole with solely one TENG sensor, creating a most simplified system that utilizes machine learning (ML) for personalized motion monitoring, encompassing identity recognition and gait classification. A cushion with 12 TENG sensors achieves real-time identity and sitting posture recognition with accuracy rates of 98.86% and 98.40%, respectively, effectively correcting sedentary behavior. Similarly, a smart pillow, equipped with 15 sensory channels, detects head movements during sleep, identifying 8 sleep patterns with 96.25% accuracy. Ultimately, constructing an AIoT-based health management system to analyzes these data, displaying health status through human-machine interfaces, offering the potential to help individuals maintain good health.

Photothermal devices and thermoelectric cells hold great promise for energy generation but integration of the two remains a considerable challenge in real-life power supply for sensors. Here, a novel photo-thermo-electric hydrogel (PTEH-Interlocking) was constructed by synthesis of a photothermal layer on a thermoelectric hydrogel with the redox pair Fe(CN)63−/Fe(CN)64−. The smart design of using oxidation of pyrogallic acid by Fe(CN)63− to construct the photothermal layer for photo-to-heat conversion protected the redox couple of the thermogalvanic ion pair from ultraviolet damage, as well as triggered the formation of an interlocking structure at the interface of the photothermal layer and the thermoelectric hydrogel. The as-prepared PTEH-Interlocking have shown a high Seebeck coefficient and rapid heat transfer, boosting the photo-thermo-electric conversion. As a demonstration of a practical application, the PTEH-Interlocking cells is successfully used as the energy supply for a mechanical sensor.

Eco-friendly and sustainable energy harvests that can alleviate concerns on the energy crisis and environmental pollution are in demand. Exploiting nature-derived biomaterials is imperative to develop these carbon-neutral energy harvesters. In this study, lignin/polycaprolactone nanofiber (NF)-based triboelectric nanogenerators (TENGs) are fabricated using an electrospinning technique. Nanotextured morphology of electrospun lignin/polycaprolactone NFs and wettability modification of lignin into hydrophilicity can significantly enhance electron transfer between tribopositive and tribonegative materials, resulting in the highest energy-harvesting efficiency in their class. The output voltage of the lignin-based TENG exceeds 95 V despite relatively low tapping force of 9 N and frequency of 9 Hz. Various mechanical and physicochemical characterizations, including scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) analysis, and atomic force microscopy (AFM), are performed, confirming the mechanical durability, biocompatibility, and industrial viability of lignin-based TENG developed here.

Solar-driven interfacial evaporation is a sustainable and economical technology for fresh water generation. Structural design of photothermal material is an effective strategy to improve the evaporation performance but usually bothered by complicated processes and non-adjustability. Herein, magnetic nanoparticles assembled photothermal evaporator was developed, which showed an adjustable spinal array surface under uniform magnetic field induction. By regulating position in the magnetic field, the desirable surface structures could be uniform at relatively low load density of magnetic nanoparticles to improve light absorption via multiple reflection. Magnetic field induced evaporator could accelerate evaporation to over 1.39 kg m-3 h-1 under 1-sun illumination, which was 2.8 times that of natural evaporation. After coated by carbon layer, magnetic nanoparticles could overcome the oxidation to realize stable evaporation in long-term desalination. The facile strategy to optimize the surface structure via magnetic field is appropriate for various fields with special requirements on surface structure.

Global warming has been affecting human health, including direct mortality and morbidity from extreme heat, storms, drought and indirect infectious diseases. It is not only “global” but extremely “personal” – it is a matter of life and death for many of us. In this perspective, we propose the use of wearable technologies for localized personal thermoregulation as an innovative method to reduce the impact on health and enable wider adaptability to extreme thermal environments. The start-to-art thermoregulation methods and wearable sensing technology are summarized. In addition, the feasibility of thermoregulation technology in preventive medicine for promoting health under climate change is comprehensively discussed. Further, we provided an outlook on health-oriented closed loop that can be achieved based on parallel thermoregulation and multiple data inputs from the physiological, environmental, and psychological cues, which could promote individuals and the public to better adapt to global warming.

Although three-dimensional (3D) host is effective in restricting Li dendrite growth, problems associated with the unstable electrode/electrolyte interphase becomes more severe due to increased interfacial area that is intrinsic of the 3D structures, being a major cause for the low Coulombic efficiency.While building a desirable solid electrolyte interphase (SEI) serves as an effective solution to improve the electrode/electrolyte interfacial stability, the 3D nature of the electrode makes the task challenging.Herein,we demonstrated the in-situ formation of SEI on chemically/structurally modified carbon cloth that is used as the 3D host.We shown that ZnS/ZnO nanotube arrays uniformly grown on the carbon cloth served as precursors for the in-situ formation of Li2S/Li2O/LiZn containing artificial SEI. While Li2S and Li2O are preferred components in SEI, Zn functions as lithiophilic site that guides the uniform lithium deposition.The present work shed light on effective design strategies for SEI formation on 3D electrode host with controllable SEI composition.

Sulfide solid state electrolyte (SSE) possesses high ionic conductivity and great processability but suffers from narrow electrochemical window. Conversion sulfide cathode FeS2 has higher specific capacity and moderate redox potential, making it appropriate towards sulfide SSE. However, the complex reaction pathway and capacity fading mechanism in FeS2 are rarely studied, especially in all-solid-state lithium battery (ASSLB). Herein, argyrodite sulfide SSE is paired with FeS2 to investigate the electrochemical reaction pathways and the capacity fade mechanism. Instead of single conversion reaction, an anionic redox driven reaction of FeS2 is revealed. The oxidization of Li2S vanishes and large quantity of inactive Li2S accumulates to cause the interfacial deterioration, along with the stress concentration during cycling, which leads to the rapid capacity fade of FeS2. Finally, a simple strategy of slurry-coated composite electrode with highly conductive network is proposed to direct the uniform deposition of Li2S and alleviate the stress concentration.

The liquid-like thermoelectric materials have fascinated extensive attention in the field of waste heat recovery into useful energy. In this aspect, di-chalcogenides Cu2X were considered superionic thermoelectric materials due to their highly disordered degree of Cu-ion in the lattice, which realizes the ultralow thermal conductivity. However, their rigid sublattice can decently maintain the electrical performance, and thus make this group distinct from the other state-of-the-art thermoelectric materials. This review summarizes the well-designed strategies to realize the impressive performance in thermoelectric materials and their modules by linking the adopted approaches, with the moderate design of the device. Some recent reports are selected to outline the fundamentals, underlined challenges, outlooks, and future development of Cu2(S, Se, Te) liquid-like thermoelectric materials. We expect that this review will cover the needs of future researchers in choosing some potential materials to further explore thermoelectricity in other energy storage and efficient conversion technologies.

Despite of superior performance of the oxide-derived copper (OD-Cu) in producing valuable hydrocarbons during CO2RR, its fabrication process is still ambiguous and complicated. In this work, we develop a simple microwave-assisted method to synthesize the oxide-derived Cu nanosheet (OD-Cu NS) and reveal that the oxidation state of Cu species is controlled by varying the Cu precursor amount. Notably, the simultaneous formation of nano-sized Cu domains influence the surface roughness of OD-Cu NS. The partially oxidized Cu surface exhibits a superior faradaic efficiency (FE) of C2+ products up to 72%, along with a partial current density of 55 mA cm−2 in a neutral KHCO3 solution. More importantly, the as-obtained OD-Cu NS shows a synergetic effect on dissociating of CO2 molecules by the strong binding energy and promoting of C2+ compounds productivity by the enlarged electrochemical surface area. This work provides a new insight for designing efficient OD-Cu catalysts towards CO2RR.

An effective method for obtaining large amounts of metal nanoparticles encapsulated by carbon layers through upcycling from floating-catalyst aerosol chemical vapor deposited carbon nanotubes is demonstrated. Nanoparticles with diameters of less than 20 µm are selectively extracted from the synthesized carbon assortments through sonication, centrifugation, and filtration. The particles show an aggregation behavior owing to the π–π interaction between the graphitic carbon shells surrounding the iron carbides. By controlling the degree of the aggregation and arrangement, the light scattering by the gap-surface plasmon effect in perovskite solar cells is maximized. Application of the nanoparticles to the devices increased the power conversion efficiency from 19.71% to 21.15%. The short-circuit current density (JSC) trend over the particle aggregation time accounts for the plasmonic effect. The devices show high stability analogue to the control devices, confirming that no metal-ion migration took place thanks to the encapsulation.