Search Results (583)

Alkaline nickel zinc batteries feature high safety, low cost and eco-friendly characteristics, making them highly promising for large-scale energy storage deployment. However, their practical application is severely constrained by the cathode’s electrical conductivity, available active sites, and cycling stability. Herein, vertical 2D hierarchical flake-like NiCoS_x arrays were in situ grown on nickel foam (NF) via a facile alkali-free solvothermal and in situ sulfidation approach. This highly interconnected and open porous flaky structure significantly shortens the ion diffusion pathways, exposes abundant redox-active sites, and accelerates electron transport, imparting excellent rate performance and superior long-cycle stability to the material. The optimized NiCoS_x/NF electrode achieves a high specific capacity of 323 mAh g⁻¹ at 0.5 A g⁻¹, along with excellent capacity retention capability. Assembled with a commercial Zn anode, the NiCoS_x/NF//Zn full battery delivers 124 mAh g⁻¹ at 3 A g⁻¹, and maintains 112.5% of the initial capacity after 500 cyclic tests. Moreover, the assembled NiCoS_x/NF//Zn full cell possesses a high energy density of 615.2 Wh kg⁻¹ along with a power density of 38.6 kW kg⁻¹ (based on the mass of positive electrode active materials). This unique vertical 2D open hierarchical structure plays a crucial role in enhancing the electrochemical performance of cobalt sulfide cathodes and provides valuable insights for the design of high-performance alkaline zinc-based battery electrodes. Full article

To meet the growing demand for materials combing high thermal conductivity and electrical insulation, we developed epoxy (EP) composites filled with zero-dimensional (0D) silver nanoparticles (AgNPs) and two-dimensional (2D) boron nitride nanosheets (BNNSs). This hybrid filler system synergistically enhances both thermal conductivity and dielectric properties, while retaining excellent electrical insulation. With only 1 wt% AgNPs and 15 wt% BNNSs, the composite achieved a dielectric constant of 4.17 at 100 Hz, outperforming pure EP. At 30 wt% BNNSs and the same AgNP loading, the in-plane and out-of-plane thermal conductivities reached 3.02 and 0.41 W·m⁻¹·K⁻¹, respectively, along with improved thermal stability. Moreover, the composite exhibited an electrical conductivity below 10⁻⁹ S/cm at 1000 Hz, confirming that the minimal metal filler content negligibly affects insulation. Thus, this work offers a feasible strategy for designing next-generation high-performance composites using 0D/2D hybrid fillers, highlighting their promising potential for advanced electronic packaging. Full article

Microbial fuel cells (MFCs) are promising bioelectrochemical systems for simultaneous wastewater treatment and energy recovery. However, their practical application is still limited by insufficient power output and weak transient energy-supply capability under fluctuating operational conditions. Herein, a bifunctional CF/MXene/FeS composite anode was fabricated through a one-step hydrothermal strategy to simultaneously enhance electricity generation and capacitive charge storage in MFCs. Unlike conventional bioanode modifications that primarily target conductivity enhancement alone, the constructed hierarchical composite integrates conductive MXene nanosheets and electroactive FeS phases to synergistically improve extracellular electron transfer and interfacial charge-storage behavior. The modified electrode exhibited enhanced surface roughness, abundant electroactive sites, and improved biofilm-supporting interfaces. Benefiting from the integrated conductive and electroactive composite framework, the CF/MXene/FeS anode achieved a maximum power density of 1.69 W/m², which was 70.7% higher than that of pristine CF, together with an increased open-circuit voltage of 0.711 V. In addition, the composite electrode delivered a high total charge density of 13,192.09 C/m² under the C900/D900 condition. Microbial community analysis further revealed substantial enrichment of electroactive bacteria, with the relative abundance of Geobacter increasing from 0.0058% to 22.84%. This work provides a promising strategy for integrating electricity generation and transient energy storage in bioelectrochemical systems, offering potential applications for energy-buffered MFCs under fluctuating power-demand conditions. Full article

Nitrogen dioxide (NO₂) is a highly toxic oxidizing gas; therefore, the development of highly reliable room-temperature (RT) gas sensors with low power consumption is important for practical applications. Herein, WS₂ nanosheet (NS)–SnO₂ nanowire (NW) nanocomposites were synthesized and subsequently decorated with Au nanoparticles (NPs) using a UV irradiation method. The SnO₂ content (1, 5, and 10 wt%) and UV irradiation time (1, 15, and 30 s) were systematically optimized to improve sensing performance. Among the prepared samples, the composite containing 5 wt% SnO₂ (SW5) exhibited the highest response among the Au-free sensors, while the 15 s UV-treated sample (15Au-SW5) showed a significantly enhanced response of 11.7 toward NO₂ at RT. The optimized sensor demonstrated reliable ppb-level detection, with an estimated experimental limit of detection of ~40 ppb and good selectivity, repeatability, and long-term stability. The improved performance is considered to be associated with the combined effects of WS₂–SnO₂ heterojunctions and Au-induced surface modulation, which may facilitate charge transfer and increase the density of reactive sites. This study highlights that the integration of 2D/1D heterostructures with controlled noble metal decoration is an effective approach for achieving high-performance RT gas sensors. Full article

The development of highly efficient and stable photoanodes is essential for advancing photoelectrochemical cathodic protection towards practical applications. Herein, a novel ternary sulfide heterojunction was engineered through the construction of a three-dimensional interlocked architecture of ZnIn₂S₄ on SnIn₄S₈ nanosheets via a sequential hydrothermal synthesis. This unique three-dimensional interlocked configuration creates an intimate interface and continuous charge transfer highways, effectively addressing the slow electron movement and poor interfacial contact that plague conventional photoelectrodes. Spectroscopic and electrochemical analyses verified the formation of a Type-II band alignment, which drives the directional migration of photogenerated electrons from ZnIn₂S₄ to SnIn₄S₈ under an intrinsic built-in electric field. Upon coupling with 304 stainless steel, the ZnIn₂S₄/SnIn₄S₃ heterojunction exhibited outstanding photoelectrochemical cathodic protection performance. It delivered impressive photocurrent densities of 15.22, 19.76, and 72.27 μA·cm⁻² in 3.5 wt% NaCl, 0.1 M Na₂S₂O₃, and 0.1 M Na₂S/NaOH electrolytes, respectively, along with a prominent 720 mV cathodic potential shift in the Na₂S/NaOH system. Most importantly, its good activity and stability in the scavenger-free 3.5 wt% NaCl solution and natural seawater highlight the strong practical potential of this 3D interlocked photoanode for sustainable marine metal corrosion control. Through a strategic multi-electrolyte assessment, the underlying protection mechanisms were decoupled, revealing that the synergy between the heterojunction-induced charge separation enabled by the three-dimensional interlocked structure and electrolyte-specific hole scavenging is key to the enhanced performance. Full article

Nonaqueous potassium-ion batteries (KIBs) are emerging as promising next-generation energy storage systems owing to their abundant resources and high energy density. However, their large-scale application is hindered by structural degradation and sluggish kinetics resulting from the large ionic radius of K ions. Engineering electrode materials with open frameworks, such as two-dimensional (2D) layered structures, present an effective strategy to address these challenges by providing rapid ion diffusion pathways and robust host structures. Herein, a rational interlayer engineering strategy is developed by intercalating phenylamine derivatives with varying molecular sizes (P-butylaniline: PTA, P-Methylaniline: PMA, and phenylamine: PA) into layered 2D VOPO₄ nanosheets. The intercalation of PANI derivatives progressively expands the interlayer spacing from 0.76 nm (pristine VOPO₄) to 1.58, 1.85, and 2.09 nm, while maintaining the structural integrity of the layered framework. Notably, the regulated interlayer expansion (from 0.76 to 2.09 nm) not only provides enlarged diffusion pathways for rapid K⁺ ion intercalation/deintercalation kinetics, but also facilitates the formation of oxygen vacancies that may serve as additional active sites for potassium storage. By correlating the electrochemical performance with the modulated interlayer distances, it is established that a preferred spacing of 1.85 nm achieves the best synergy between fast kinetics, high capacity, and structural stability. As expected, the electrode with the optimal interlayer spacing (1.85 nm) exhibits superior potassium-ion storage performance, delivering a high reversible capacity of 333.2 mAh g⁻¹ at 0.1 A g⁻¹ over 100 cycles and exceptional rate capability with 205.7 mAh g⁻¹ retained at 1 A g⁻¹, as well as maintaining remarkable stability up to 600 cycles even at high rates. This work innovatively proposes phenylamine derivative-enabled interlayer regulation as a promising approach for designing high-performance VOPO₄-based electrode materials. Full article

The key transformation of 2D Ti₃C₂ MXene nanosheets into 0D Ti₃C₂ MXene quantum dots (Ti₃C₂ QDs) restructures the landscape of surface-active sites and tunable band gaps, enabling visiblelight-driven photocatalytic activity. Interestingly, the evolution of these fascinating Ti₃C₂ QDs retains ordered structural characteristics like the parent 2D Ti₃C₂ MXene nanosheets with controlled surface chemistry even after the facile hydrothermal process. In particular, evidence of tailoring of Ti₃C₂ QDs smaller than 10 nm reinforces the charge carrier separation and suppresses recombination under the strong association of quantum confinement and edge effects. Thus, the physical effects of Ti₃C₂ QDs effectively control the limitations of semiconductors, such as charge carrier recombination, slow charge carrier separation, and transportation in the resultant photocatalyst, for the implementation of promising toxic matter degradation and clean H₂ production. Special considerations are given to the regulation of charge carrier generation and separation for stable photocatalytic performance, such as appropriate band gap formation, localized surface plasmonic behavior, and Schottky barrier formation at the semiconductor interface. Specifically, pure Ti₃C₂ QDs with a size smaller than 10 nm exhibit a band gap of 2.16 eV, which has been found to be a powerful way to enable semiconductor-like photoresponse behavior. Overall, the above features make Ti₃C₂ QDs the preferred choice for facilitating effective charge carrier dynamics for the optimization of chemical stability in optoelectronic applications. The paper concludes with challenges and future perspectives to guide the 0D Ti₃C₂ QDs practical applicability in light-driven and sustainable environmental applications. Full article

To overcome the inherent limitations of 2D MXenes in photocatalysis, namely severe nanosheet restacking and rapid charge recombination, this study reports a synergistic dual-modification strategy. By integrating microwave-assisted in situ growth of carbon nanotubes (CNTs) with the hydrothermal incorporation of multivalent cobalt (Co) species, a 3D hierarchical Co-Ti₃C₂/CNT composite was successfully fabricated. Structural characterization reveals that the in situ grown CNTs act as robust spatial spacers and conductive highways, effectively preventing Ti₃C₂ agglomeration while providing a continuous electron-transfer network. The introduction of Co significantly enriches the surface with redox-active sites and facilitates the formation of an interfacial Schottky junction. Under visible-light irradiation, the optimized Co_10%-Ti₃C₂/CNT composite achieved a superior methylene blue degradation efficiency of 90.3% within 120 min. Mechanistic insights, supported by EPR and electrochemical analyses, confirm that the Schottky barrier at the semiconductor-metal interface acts as a potent electron trap, significantly suppressing e⁻/h⁺ recombination and accelerating surface-mediated radical generation (•OH, •O₂⁻). This work provides a sophisticated template for designing high-performance, dimensionally stable MXene-based heterostructures for advanced environmental remediation. Full article

A layered bimetallic CoMo-LDH precursor was prepared on nickel foam via a hydrothermal method, and a 3D hierarchical flower-like nanosheet CoMoP/NF electrocatalyst with a crystalline–amorphous heterostructure was constructed in situ through low-temperature phosphidation. The water electrolysis performance was optimized by adjusting the Co/Mo molar ratio. The 3D hierarchical porous structure provides a large specific surface area and abundant active sites, and Mo doping effectively modulates the electronic structure. The catalyst exhibits superior HER performance with overpotentials of only 37 mV and 65 mV at 10 mA·cm⁻² in acidic and alkaline media and shows a lower HER overpotential than commercial Pt/C at current densities above 426 mA·cm⁻² in acidic conditions. Meanwhile, this catalyst delivers an OER overpotential of 729 mV at 500 mA·cm⁻² in alkaline media and can operate stably for 50 h. The assembled two-electrode overall water splitting cell only requires 1.42 V at 10 mA·cm⁻², outperforming Pt/CǁRuO₂ (1.52 V). This work offers a promising strategy for designing low-cost and high-efficiency overall water splitting electrocatalysts for high-current-density applications. Full article

MXenes, with a high surface area, abundant active sites, and excellent ion transport properties, have demonstrated excellent electrochemical performance. However, systematic comparisons of the structural evolution process and electrochemical performance for MXene are lacking. In this study, multilayer MXene (M-Ti₃C₂T_x) was successfully fabricated by in situ etching. During the subsequent centrifugation process, the thicker and heavier multilayer sheets settled due to their faster sedimentation rate, while the lighter, surface-functionalized monolayer sheets remained colloidally stable in the supernatant due to solvation and electrostatic repulsion, thereby achieving separation and obtaining delaminated MXene (D-Ti₃C₂T_x). Structural analysis indicates that the removal of the aluminum layer synergizes with the exfoliation of the nanosheets, significantly increasing the interlayer spacing and making the sheet structure more pronounced, and the pore structure is more abundant. Especially, in three-electrode and two-electrode systems at an identical mass loading of 5 mg on carbon paper, D-Ti₃C₂T_x delivered a higher specific capacitance, more pronounced pseudocapacitive behavior, and a superior rate capability compared to Ti₃AlC₂ and M-Ti₃C₂T_x. Such excellent electrochemical performance of D-Ti₃C₂T_x is due to the shortened ion diffusion path in the delaminated structure, which enables rapid ion migration, an extremely large specific surface area, and a mesoporous structure that provides abundant active sites. This study underscores the significant potential of D-Ti₃C₂T_x in emerging energy storage systems and offers insights into guiding MAX phase synthesis during its preparation. Full article

The global energy transition and the implementation of carbon capture, utilization, and storage (CCUS) strategies require energy-efficient and scalable CO₂ separation technologies. Mixed-matrix membranes (MMMs), combining polymer matrices with functional inorganic or hybrid nanofillers, have emerged as advanced separation platforms capable of surpassing the conventional permeability–selectivity trade-off observed in neat polymer membranes. This review critically evaluates recent developments in modern hybrid membranes for CO₂ separation from synthetic and industrial gas mixtures, including CO₂/N₂ (flue gas), CO₂/CH₄ (natural gas and biogas upgrading), and syngas systems. Particular emphasis is placed on MMMs incorporating covalent organic frameworks (COFs), metal–organic frameworks (MOFs), graphene oxide (GO), MXenes, transition metal dichalcogenides (TMDs), carbon nanotubes (CNTs), g-C₃N₄, layered double hydroxides (LDH), zeolites, metal oxides, and magnetic nanoparticles. Reported performance ranges include CO₂ permeability (P_CO2) typically between 100 and 800 Barrer, CO₂/N₂ selectivity up to 319, and CO₂/CH₄ selectivity up to 249, depending on filler chemistry, loading, and interfacial compatibility. The mechanisms governing gas transport—molecular sieving, selective adsorption, facilitated transport, and diffusion-pathway engineering—are systematically discussed. Key challenges addressed include filler dispersion, polymer–filler interfacial defects, physical aging, moisture sensitivity, oxidation (particularly in MXenes), and scalability toward industrial membrane modules. Future perspectives focus on sub-nanometer pore engineering, surface functionalization to enhance CO₂ affinity, controlled alignment of 2D nanosheets to promote directional transport, multifunctional core–shell and hollow structures, and the integration of computational modeling and machine learning for accelerated material design. Modern hybrid MMMs are identified as strategically important materials enabling high-efficiency CO₂ separation processes aligned with decarbonization and energy transition objectives. Full article

The transformation of waste plastics into hydrogen and functional carbon (C) materials represents a promising pathway for achieving both resource recycling and the production of value-added products. Owing to their tunable physicochemical properties, plastic-derived carbons have attracted significant attention in electrochemical energy storage applications. Various C nanostructures, including graphene, porous C, hard C, and C nanotubes (CNTs), can be generated from discarded plastics through thermochemical processes. The electrochemical performance of these materials is closely governed by their structural characteristics, such as pore architecture, specific surface area, heteroatom doping, surface functionalities, and dimensional morphology. This review aims to provide a comprehensive and systematic overview of the conversion of waste plastics into functional C nanomaterials via thermochemical routes, particularly catalytic pyrolysis and carbonization. The resulting C nanostructures are systematically categorized based on their dimensional architectures (0D, 1D, 2D, and 3D) and comparatively analyzed in terms of their structural features and electrochemical performance. Emphasis is placed on the transformation of diverse plastic feedstocks into high-value C materials with tailored dimensional architectures, including graphene, CNTs, C nanospheres, C nanosheets, porous carbons, and their composites. Furthermore, recent progress and critical challenges in utilizing these materials for electrochemical energy storage systems, such as supercapacitors and rechargeable batteries (Li-ion, Na-ion, K-ion, Li-S, and Zn-air), are discussed. Distinct from previous reports, this review highlights the correlation between thermochemical processing strategies, resulting structural features, and electrochemical performance, providing new insights into the rational design of high-performance C materials. These findings are expected to facilitate the advancement of sustainable energy storage technologies while contributing to effective plastic waste valorization. Full article

The development of cost-effective and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) is pivotal for sustainable hydrogen energy production. Herein, coaxial electrospinning one-dimensional (1D) hollow carbon nanofiber (HCNF) in situ-grown MoS₂/CoS₂ nanosheets were impregnated with a NaBH₄ solution to obtain a HCNF-loaded sulfur-vacancy-rich MoS₂/CoS₂ heterojunction nanosheets catalyst of Vs-MoS₂/CoS₂-0.1@HCNFs. The unique hollow architecture afforded by electrospinning facilitates rapid electron transport and effectively mitigates the agglomeration of active 2D nanosheets, ensuring maximum exposure of catalytic sites. Furthermore, NaBH₄ impregnation introduces abundant sulfur vacancies into the heterojunction lattice, synergistically modulating the electronic structure. Benefiting from the structural advantages of the electrospun framework and defect engineering, the optimized catalyst (Vs-MoS₂/CoS₂-0.1@HCNFs) exhibits superior HER activity in 1.0 M KOH, requiring an overpotential of only 115 mV to achieve a current density of 10 mA cm⁻², along with a low Tafel slope of 83.3 mV dec⁻¹ and excellent long-term stability. This study demonstrates the efficacy of electrospinning in designing high-performance, self-supported electrocatalysts for sustainable energy applications. Full article

The activation of molecular oxygen driven by solar energy presents a cost-effective and environmentally friendly approach in the area of environmental purification. Carbon quantum dots and semiconductor nanocomposite photocatalysts serve as an effective strategy for enhancing the separation and transport of photogenerated carriers, thereby boosting the activation of molecular oxygen. In this study, we prepared 0D tea biomass quantum dots (T-BCDs) coupled with 2D PbBiO₂Br nanosheets, which demonstrate enhanced molecular oxygen activation under visible light irradiation and were synthesized using a solvothermal method. Transmission electron microscopy (TEM) analysis reveals that T-BCDs, with diameters of approximately 5 nm, are uniformly distributed on the surface of PbBiO₂Br. Notably, experimental results indicate a strong covalent interaction between PbBiO₂Br and T-BCDs, which enhances the absorbance of visible light, facilitates the transfer and separation of interfacial photogenerated carriers, and promotes the conversion of molecular oxygen into superoxide radicals. The degradation rate constant of ciprofloxacin achieved with 5 mL T-BCDs/PbBiO₂Br is 3.3 times greater than that obtained with pure PbBiO₂Br. This research offers a promising strategy for the development of efficient 0D/2D photocatalysts aimed at sustainable environmental remediation. Full article

Bifunctional materials present a promising route to develop advanced devices, yet the dual performance of CoNi₂S₄ nanosheets anchored on a porous scaffold is seldom reported. Herein, we propose a rational fabrication strategy to construct a three-dimensional hierarchical electrode via the in-situ growth of densely aligned CoNi₂S₄ nanosheets on a conductive fabric scaffold. This integrated porous architecture concurrently offers an ultrahigh specific surface area, efficient mass transport, and rapid electron conduction. As a supercapacitor, the electrode achieves a high areal capacitance of 3198 mF cm⁻² at 4 mA cm⁻² and retains 98.1% of its initial capacitance after 1000 cycles at 20 mA cm⁻². As a non-enzymatic glucose sensor, it exhibits outstanding selectivity (<4.1% interference), high sensitivity (1049 μA mM⁻¹ cm⁻²), a wide linear range (1–8 mM), and a low detection limit (1 μM). These results highlight the significant potential of this binder-free, scaffold-supported nanosheet design for advancing integrated energy storage and biosensing systems. Full article