Nanoenergy Advances

Electrochemical CO₂ reduction reaction (ECO₂RR) is a promising technology for converting rapidly rising atmospheric CO₂—driven by fossil fuel consumption and industrial processes—into a circular carbon economy. In particular, ECO₂RR is expected to enable renewable-based long-duration energy storage (LDES) systems through the highly efficient conversion of CO₂ into high-value multi-carbon (C2⁺) compounds. However, scaling ECO₂RR to the industrial level remains challenging because, under high-current operation, the CO₂ consumption rate exceeds its supply rate, causing a sharp decline in local CO₂ concentration. The resulting increase in local pH promotes both carbonate formation and electrode flooding within the gas diffusion electrode (GDE), creating a wetting-induced mass transfer bottleneck. To address this challenge, this review categorizes and analyzes recent strategies for CO₂ microenvironment engineering that overcome mass transfer limitations at high-current densities, focusing on two complementary approaches: (1) enhancing gas-phase CO₂ supply while suppressing flooding through nano/microscale hydrophobic polymers and structural gradient designs, and (2) enhancing active CO supply in the liquid phase through electrolyte composition optimization. We further show that these strategies are not mutually independent but create complementary structural and chemical synergies, and we propose future directions for simultaneously improving high-current operability and C2⁺ product selectivity. Full article

Lithium–sulfur batteries have become one of the research focuses of scientists over the past decade due to their high theoretical specific capacity (approximately 1670 mAh/g), low cost, and environmental friendliness, and the abundant reserves of their raw materials. Nevertheless, they still suffer from inherent drawbacks including poor electrical conductivity of elemental sulfur, electrode volume expansion during charge–discharge cycles, the shuttle effect and lithium dendrite growth, which severely restrict their practical application and industrialization. To address the above issues, extensive research has been carried out to optimize cathode materials, separators and electrolytes. In particular, the shuttle effect occurring during cycling can be effectively mitigated via separator modification. This paper briefly introduces the design strategies for separators for lithium–sulfur batteries, and mainly summarizes separator-modification methods using carbon materials, graphene, carbon nanotubes, heteroatoms, polymers, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). Finally, the future development trends of lithium–sulfur batteries are prospected. Full article

MXenes have attracted considerable attention as anode materials for sodium-ion batteries (SIBs) because of their metallic conductivity, hydrophilic surfaces, tunable surface terminations, and layered structures. However, pristine MXenes are limited by nanosheet restacking, oxidation instability, heterogeneous surface chemistry, low initial Coulombic efficiency, and insufficient electrode-level ion accessibility. These issues indicate that MXenes should be regarded not simply as standalone active materials but as multifunctional building blocks for composite electrode design. This review discusses recent progress in MXene-based composite anodes for SIBs, focusing on MXene/carbon composites, MXene/metal compound composites, polymer-assisted composites, and three-dimensional structured MXene composites for improving structural stability, interfacial chemistry, and sodium-storage kinetics. We emphasize that composite engineering can reshape sodium storage from diffusion-limited intercalation toward hybrid mechanisms involving interfacial adsorption, pseudocapacitive storage, heterointerface-driven redox reactions, ion desolvation regulation, and solid-electrolyte interphase stabilization. Key practical challenges, including oxidation control, initial Coulombic efficiency, high-mass-loading electrode design, gravimetric–volumetric performance trade-offs, scalable synthesis, and full-cell validation, are also discussed. Finally, we propose future design principles based on integrated materials chemistry, interfacial science, multiscale architecture engineering, and realistic cell-level evaluation for advancing MXene composites toward practical SIB anodes. Full article

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes are regarded as highly promising solid electrolyte materials owing to their favorable chain flexibility. However, their practical application is hindered by low room-temperature ionic conductivity and poor mechanical properties. To address these issues, a metal–organic framework (Cu-MOF) with a 2D layered structure and 1D microchannels is introduced into PEO to form a composite solid electrolyte. The results reveal that Cu-MOF can suppress PEO crystallization through steric hindrance and coordination interactions, thereby increasing the fraction of the amorphous phase. Moreover, its unsaturated metal sites can attract TFSI⁻ anions, promoting the dissociation of the sodium salt and enhancing sodium-ion transport. Theoretical calculations and molecular simulations further confirm the regulatory role of Cu-MOF in ion transport. Leveraging this mechanism, the Na₃V₂(PO₄)₃/C|PCM-8%|Na cell delivers exceptional electrochemical performance over a wide temperature range. At room temperature, the capacity exhibits virtually no decay after 200 cycles at 0.5 C, and outstanding rate capability is maintained even at a high rate of 4 C. At a temperature of 65 °C, a capacity retention of 91.4% is achieved after 200 cycles at 0.5 C. This study offers a highly promising strategy for the development of wide-temperature-range, high-performance solid-state sodium batteries. Full article

Lead-ion (Pb²⁺) contamination in drinking water poses a serious threat to public health, but conventional laboratory-based methods rely on bulky equipment and are unsuitable for on-site monitoring. Here, we develop a wireless monitoring system based on a dual-channel liquid–solid triboelectric nanogenerator probe (TENG probe) for detecting Pb²⁺ in drinking water. Based on the dynamic contact electrification at the liquid–solid interface, the sliding of a water droplet containing Pb²⁺ on the FEP surface is converted into an electrical signal for Pb²⁺ detection. A wireless acquisition circuit transmits the electrical signals via Wi-Fi to a computer, enabling remote and wireless detection. By integrating a one-dimensional convolutional neural network (1D CNN) deep learning model, the TENG probe achieved a detection accuracy of 99.62% and was capable of detecting Pb²⁺ in drinking water at the ppb level, exceeding the national standard. This work opens a way for safeguarding drinking-water quality. Full article

Y-doped HfO₂ ferroelectric thin films were fabricated via the sol–gel chemical solution deposition method. The effects of Y doping concentration, film thickness, and annealing temperature on the structure, morphology, and electrical properties were systematically investigated. The results demonstrate that doping concentration, film thickness, and annealing temperature can significantly regulate the crystalline phase composition. Appropriate doping, moderate film thickness, and suitable annealing temperature effectively stabilize the ferroelectric orthorhombic phase and suppress the monoclinic phase. The optimized film is obtained under the conditions of 4 mol% Y doping, a film thickness of 59.2 nm, and rapid thermal annealing at 600 °C, which exhibits the best crystallinity, dense and flat surface, and moderate oxygen vacancy concentration. The optimized sample shows a remnant polarization of 86.9 μC/cm², a coercive field of 1.1 MV/cm, and a leakage current density as low as 9.77 × 10⁻⁶ A/cm², representing the best ferroelectric performance. This study provides a reliable process and experimental basis for the preparation of high-performance HfO₂-based ferroelectric thin films by the sol–gel method. Full article

In this study, an electrochemical system for methane conversion was developed, employing Ni- and Ce-doped LaCoO₃ perovskite as the anode catalyst in an Na₂CO₃ electrolyte. Structural characterization revealed that the La_1−yCe_yCo_1−xNi_xO₃ (x = 0–0.5, y = 0–0.12) synthesized by the sol–gel method maintains the perovskite structure, but is rich in oxygen vacancies. Electrochemical studies revealed that the performance of methane activation is related to the presence of Ni(III) in the catalyst, and reactive oxygen species (•OH and HOO⁻) are provided through water oxidation reactions (WOR) in the Na₂CO₃ electrolyte. The electrocatalytic performance of the synthesized La_0.92Ce_0.08Co_0.5Ni_0.5O₃ during methane conversion was verified in an electrolysis cell, and ethanol and acetic acid were identified as the methane conversion oxygenates. Under ambient conditions, the formation rate of ethanol reached 577.0 μmol g_cat⁻¹ h⁻¹ at 0.90 V (vs. Ag/AgCl) in 0.5 mol L⁻¹ Na₂CO₃. The catalyst was found to retain structural integrity and sustain catalytic activity over multiple reaction cycles. Full article

We report a low-temperature plasma–liquid synthesis of crystalline β-Ga₂O₃ nanoparticles directly from aqueous solution. Pulsed discharge plasma bubbles generate reactive species that drive in situ dehydration and crystallization, bypassing the high-temperature calcination required by conventional methods. By varying the carrier gas, we tune morphology from uniform nanorice structures (He, Ar, and N₂) to amorphous microspheres (O₂ and air), revealing how plasma composition governs interfacial hydroxyl radical chemistry and growth kinetics. This approach demonstrates that localized plasma heating and reactive-species flux can achieve phase-selective oxide crystallization under ambient conditions, establishing plasma bubble reactors as a broadly applicable, low-temperature route for direct aqueous synthesis of crystalline wide-bandgap oxides that bridge solution chemistry and plasma nanomaterials design. Full article

The development of sustainable technologies capable of simultaneously addressing environmental pollution and renewable energy production remains a major scientific challenge. In this work, titanium dioxide nanoparticles (GTiO₂) were synthesized through a plant-extract-assisted route using Punica granatum (pomegranate) peel extract and subsequently modified with platinum nanoparticles (Pt NPs) to obtain an efficient photocatalyst for the photoreforming of organic pollutants. The resulting Pt-GTiO₂ material exhibited an anatase crystal structure with an average crystallite size of approximately 12 nm and a specific surface area of about 140 m² g⁻¹. Comprehensive characterization using XRD, BET, TEM, FTIR, Raman, and photoluminescence spectroscopy (PL) revealed favorable structural and optoelectronic properties that promote efficient charge separation. The photocatalytic performance of Pt-GTiO₂ was evaluated through the simultaneous degradation of 2-naphthol, a priority aromatic pollutant, and hydrogen evolution under simulated solar irradiation in anaerobic conditions. Under the investigated conditions, Pt-GTiO₂ effectively promoted 2-naphthol degradation, with substantial but incomplete mineralization, as confirmed by TOC removal. The synthesized catalyst showed degradation efficiency higher than Pt-UV100 and comparable to Pt-P25, while exhibiting superior hydrogen evolution when compared with Pt-P25. Mechanistic investigations combining scavenger experiments, electron paramagnetic resonance (EPR) spectroscopy, and the identification of reaction intermediates suggest that photogenerated holes play a major role in the initial oxidation step under the mechanistic test conditions. The detected intermediates indicate that photoreforming proceeds via multiple pathways, including hydroxylation, ring-opening, reduction, and fragmentation. These findings highlight the potential of biogenic TiO₂-based photocatalysts for converting hazardous organic pollutants into clean hydrogen fuel while simultaneously achieving wastewater purification, offering a promising route toward sustainable environmental and energy technologies. Full article

A comprehensive first-principles investigation of bulk and surface Cu defects in Zn-based chalcogenides (ZnO, ZnS, and ZnSe) is presented, aimed at assessing the effect of Cu doping on the optoelectronic properties of these materials and at addressing the photocatalytic activity towards the hydrogen evolution reaction (HER). Defect formation energies, adiabatic and optical charge-transition levels of the bulk materials are determined, and their dependence on growth conditions and Fermi-level position is analysed. The results indicate that, whereas ZnO supports both donor- and acceptor-like Cu defects with pronounced Jahn-Teller distortions, ZnS and ZnSe predominantly stabilise substitutional Cu as a mid-gap acceptor with weaker electron-lattice coupling and similar absolute transition levels. Calculated vertical transition energies rationalise the characteristic emission of Cu-doped samples in terms of defect-mediated optical cycles. The focus is then placed on surface energetics, which differ markedly from bulk behaviour and critically influence photocatalytic performance. Explicit modelling of HER demonstrates that Cu substitution dramatically reduces the overpotential on ZnS and ZnSe by tuning hydrogen adsorption toward the Sabatier optimum, while in ZnO the beneficial effect of Cu doping is diminished by the excessive strengthening of the adsorbate-surface interactions. Finally, the measured HER activities are rationalised by proposing a defect-mediated mechanism involving electron trapping at the surface Cu site, cooperative proton adsorption, and hydride formation. These findings establish defect thermodynamics and surface charge localisation as key design parameters for optimising materials engineering strategies in photocatalytic applications. Full article

The mechanical sensitivity of energetic materials is closely linked to the stability of their microstructures; however, in situ observation of their dynamic response under external mechanical stimuli at the atomic scale remains challenging. Here, we propose a deep-learning-based intelligent analysis method for scanning tunneling microscopy (STM) images of a next-generation insensitive energetic material 3-nitro-1,2,4-triazol-5-one (NTO). We design SpecMol, a lightweight segmentation network with frequency-domain awareness, which achieves high-precision segmentation and orientation recognition of individual NTO molecules in adsorption images. Building upon this, we apply localized external forces to one-dimensional NTO nanochains via in situ STM tip manipulation and quantitatively analyze the geometric evolution of their fundamental building blocks—dimers. Experimental results reveal that, following mechanical perturbation, the relative orientation angle within the dimer (averaging approximately 14.55°) remains highly stable (CCC = 0.834), confirming the remarkable structural rigidity of NTO dimers. This study provides, for the first time, direct microscopic evidence at real-space atomic resolution for the low mechanical sensitivity of NTO, elucidating that its exceptional local structural stability originates from rigid dimeric units stabilized by an extensive hydrogen-bonding network. Our findings not only deepen the fundamental understanding of the safety performance of energetic materials but also demonstrate the powerful potential of integrating artificial intelligence with advanced characterization techniques for molecular-scale functional materials research. Full article

The valorization of biomass waste into advanced electrode materials presents a promising pathway toward sustainable electrochemical energy storage. Herein, a silicon-doped carbon material (Si-CTS-Carbon) is synthesized from chitosan via an in situ reaction with silicon tetrachloride (SiCl₄) and subsequent controlled pyrolysis. When evaluated as an anode for lithium-ion batteries (LIBs), Si-CTS-Carbon exhibits a high reversible capacity of 509.2 mAh g⁻¹ with 99% capacity retention after 100 cycles at 0.05 A g⁻¹. For sodium-ion battery (SIB) applications, it achieves a stable reversible capacity of 155.4 mAh g⁻¹ under identical conditions. Structural and electrochemical analyses reveal that the robust C–O–Si covalent network effectively accommodates volume variation of silicon and enhances structural integrity during cycling. Furthermore, the hierarchically porous architecture shortens ion diffusion pathways, leading to improved Li⁺/Na⁺ transport kinetics. This work demonstrates a viable strategy for fabricating high-performance battery anodes by synergistically doping silicon into biomass-derived carbon, enabling practical biowaste valorization for energy storage. Full article

Sodium metal batteries (SMBs) are promising energy storage systems, yet their practical application is hindered by unstable solid electrolyte interphases (SEIs) and safety issues associated with flammable electrolytes. Although the flame-retardant solvent trimethyl phosphate (TMP) is widely used in rechargeable batteries, its application in SMBs remains constrained due to uncontrolled and accumulated parasitic reactions with sodium metal anodes. Here, we propose a novel synergistic strategy that combines a fluorinated additive (FEC) with a low-cost, high-concentration NaClO₄ to stabilize the electrode–electrolyte interface in TMP-based electrolytes. This approach enables the formation of a robust, NaF-rich SEI while restructuring the Na⁺ solvation sheath to coordinately trap TMP molecules, thereby suppressing parasitic reactions between sodium metal and TMP. As a result, the Na|Na₃(VOPO₄)₂F cell achieves exceptional cycling stability with 89.04% capacity retention over 1000 cycles at 1C. This work provides a cost-effective and practical pathway toward safe and long-lasting SMBs using non-flammable phosphate electrolytes. Full article

As a prospective two-dimensional conductive filler, titanium carbide (MXene) can remarkably boost the dielectric constant (ε) of polymer composites at low loadings. Nevertheless, the accompanied large dielectric loss (tan δ) and leakage current greatly limit their practical applications in dielectric-related fields. To tackle this dilemma, an organic polydopamine (PDA) shell was coated on an MXene surface via a self-polymerization method, and the dielectric properties of PDA-modified MXene/poly(vinylidene fluoride) (PVDF) were explored. The findings show that, in comparison to unmodified MXene/PVDF, MXene@PDA/PVDF retains a high ε and improved breakdown strength (E_b). It further realizes a notable decrease in both tan δ and electrical conductivity. The introduced PDA interlayer serves to effectively separate adjacent MXene nanosheets, which inhibits the development of conductive paths and introduces charge traps to restrict carrier migration, thus reducing tan δ. Further, the interlayer not only improves the interfacial compatibility, but also mitigates strong dielectric mismatch between MXene and PVDF, which facilitates the homogeneous redistribution of the local electric field, contributing to enhanced E_b. Theoretical fitting and simulation studies unlock the profound polarization mechanisms and charge migration modulated by the PDA interlayer. The resulting Mxene@PDA/PVDF exhibits concurrently elevated ε (35.68) and enhanced E_b (12.94 kV/mm), as well as low tan δ (0.34) at 10³ Hz and 7 wt% filler loading, which is not achievable in neat MXene/PVDF. This work demonstrates that core–shell interfacial engineering offers an effective strategy for designing flexible polymer dielectrics with superior dielectric performances, showcasing potential applications in energy storage, advanced power systems and flexible electronics. Full article

The increasing demand for higher energy density in lithium-ion batteries has driven significant interest in layered oxide cathode materials. However, their development is hindered by an inherent trade-off between structural stability and ion transport kinetics. This compromise often manifests as a conflict between achieving high capacity, long cycle life, and excellent rate performance. Consequently, mitigating structural degradation and minimizing interfacial side reactions have emerged as core research priorities. Based on this, this review summarizes the crystal chemistry and key challenges of three main types of layered oxide cathode materials, and critically evaluates two main modification strategies: bulk doping, which enhances performance by regulating the electronic structure and suppressing phase transitions; and surface coating, which builds a protective layer at the particle–electrolyte interface to suppress side reactions and metal dissolution. Looking ahead, in terms of modification, the focus should be on multi-scale co-doping to construct a stable bulk phase structure and multi-functional coating to optimize the interface. Integrating artificial intelligence with high-throughput computation will powerfully enable the pursuit of these advanced modification strategies. This integrated approach may resolve the fundamental contradiction between energy density and stability, thereby paving a new pathway for next-generation lithium-ion batteries. Full article

A hybrid material based on the copolymerization of EDOT (3,4-ethylenedioxythiophene) and Py (pyrrole), 1:1 monomer ratio, onto multi-walled carbon nanotubes (MWCNTs) was synthesized through a multistep functionalization approach. The resulting P(EDOT-co-Py)@MWCNT hybrid, poly(3,4-ethylenedioxythiophene-co-pyrrol)@MWCNT hybrid, was characterized by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These characterizations confirmed the successive functionalization steps, the effective anchoring of the monomers, and the subsequent formation of the copolymer. Transmission electron microscopy (TEM) images revealed a homogeneous polymer coating along the nanotube surface while preserving the structural integrity of the MWCNTs throughout the functionalization and polymerization processes. The P(EDOT-co-Py)@MWCNT hybrid was evaluated as an active electrode material for aluminum-ion storage in an aqueous aluminum sulfate electrolyte. The system exhibited two distinct charge-storage mechanisms: at high current densities, proton surface adsorption dominated, whereas at lower rates, a faradaic contribution associated with polymer chain redox activity and the reversible extraction/insertion of Al³⁺ became prevalent. The hybrid electrode delivered high specific capacities, reaching 200.6, 106.3, and 44.3 mAh g⁻¹ at 0.10, 0.25, and 0.50 A g⁻¹, respectively. These values are comparable to—or even exceed—those reported for similar cathodic materials designed for Al³⁺ storage, highlighting P(EDOT-co-Py)@MWCNT hybrid as a highly promising cathode candidate for aqueous aluminum-ion energy-storage systems. Full article

NiO electrochromic films have significant potential for applications in smart windows, displays, energy-efficient buildings, and portable electronics, owing to their excellent electrochemical stability, favorable optical modulation performance, and environmental friendliness. However, several challenges remain, such as limited long-term durability, stability under extreme environmental conditions, and the cost-effectiveness of large-scale production. Future research efforts should focus on enhancing the cyclic stability and environmental adaptability of NiO films, developing low-cost fabrication techniques, and advancing multifunctional composite materials for smart devices. This review summarizes recent advances in the preparation and performance optimization of NiO electrochromic films. Several key fabrication methods—including magnetron sputtering, hydrothermal synthesis, electrodeposition, chemical bath deposition, sol–gel processing, and spray pyrolysis—are highlighted, and their effects on film structure, thickness uniformity, and optical properties are analyzed. Furthermore, the critical role of different electrolytes (inorganic, organic, and gel-based) in the electrochromic process is discussed, with a comparative evaluation of their influence on the electrochromic performance of NiO films. This article offers a comprehensive overview of the progress in high-performance NiO electrochromic films and provides theoretical insights and technical support for their broader application in renewable energy and smart home technologies. Full article

It is of great significance to prepare carbon-supported non-noble metal catalysts for hydrogen evolution reaction (HER) via a sustainable method. Meanwhile, the enhanced metal-support interaction (MSI) is vital for promoting the catalytic activity of metal/carbon catalysts. Herein, we prepare a biomass-derived porous carbon-supported metal Ni catalyst (Ni/APC) with the enhanced MSI via atomic Ni-N₄ sites utilizing agaric as a precursor. The highly dispersed Ni-N₄ species preferentially adsorb dye molecules and reactant H₂O, beneficial to efficient electron transfer and promoting H₂O dissociation. Meanwhile, Ni nanoparticles undertake the active sites for H₂ desorption. In virtue of the synergistic effect of metal Ni nanoparticles and atomic Ni-N₄ for different roles of active sites, Ni/APC catalysts show more effective dye-sensitized photocatalytic HER activities, compared with pure Ni and pure APC. The Ni/APC catalyst with an optimal Ni loading amount exhibits a high AQY of 41.0% with an excellent long-term stability in terms of both HER activity and structure. It is the first report of an application for biomass-derived carbon catalysts in dye-sensitization hydrogen production, and the synergistic effect of atomic Ni and particled Ni on the dye-sensitized photocatalytic HER is deeply investigated. This work provides new deep insight into the design of new non-noble metal/carbon materials by taking advantage of biomass materials. Full article

Energy obtained by green ways with releasing environmental pollution is still a challenge for sustainable development for model society. Among energy technologies, photothermal conversion by using solar energy has become a new field and a hot topic in recent years. Based on the exploration of nanomaterials in the past decades, photothermal nanomaterials by using nanomaterials bring new chances for expending the utilization of green energy with high efficiency, mainly including metal semiconductors and carbon nanomaterials. Their modulated structure for enhancing light absorption, accelerating transformation of photon into heat, and located heat management were also considered important for promoting the utilization of solar energy and therefore, the strategies for designed and controllable preparing of photothermal nanomaterials were also summarized. The applications of photothermal nanomaterials were also reviewed to reveal the new chances for energy conversion engineering or promoting the solar energy utilization of solar energy in some cold regions or somewhere with low solar irradiation. Full article