Carbon

Foliar iron delivery requires simultaneous control of ferrous-state stability, nutrient transport, and leaf-surface residence, yet these functions are rarely integrated within a single formulation. Here, we developed a carbon dot-stabilized and coordination-gated nanocarrier formulation (NFCT) by co-confining Fe2+ and carbon dots (CDs) within amino-functionalized mesoporous silica and depositing an external tannic acid-Fe (TA-Fe) coordination network. Electron spin resonance measurements and density functional theory calculations support complementary contributions of the CDs to reactive-oxygen-species attenuation and Fe2+ coordination, whereas the outer metal-phenolic network provides pH-dependent regulation of nutrient transport. Under the tested storage conditions, NFCT retained 93.0% of recoverable Fe2+ after 7 d and showed substantially greater recoverable Fe2+ availability under mildly acidic than near-neutral or alkaline conditions. On model waxy leaf surfaces, NFCT improved droplet spreading and achieved 72% of the pre-rain total-Fe deposit after a 70.7 mm simulated-rainfall challenge. These redox, transport, and interfacial attributes were associated with greater foliar Fe accumulation, chlorophyll index, biomass production, and root-system remodeling in Fe-deficient rice. In a single-site, single-season proof-of-concept field trial, no statistically significant differences were detected between NFCT and commercial EDTA-Fe for the measured agronomic traits under the tested application program. The results define a carbon-dot-centered structure-property-function framework in which internal Fe2+ protection, external coordination-gated transport, and rainfast foliar residence provide complementary delivery functions.

Turbostratic graphite is a layered carbon material characterized by twisted stacking of graphene layers, which exhibits superior rate performance as an anode material for lithium-ion batteries compared to conventional AB-stacked graphite. However, the kinetics and dynamics of Li-ion diffusion between the twisted graphene layers have remained not fully understood. In this study, we elucidated the influence of twisted stacking on Li-ion diffusion through a multiscale computational analysis combining density functional theory (DFT) calculations and machine-learned interatomic potential molecular dynamics (MLIP-MD). Potential energy surfaces (PES) of Li-ion diffusion in small-scale turbostratic graphite models revealed that continuous diffusion pathways with low activation barriers are formed along AB and bridge sites. Climbing image nudged elastic band (CI-NEB) calculations quantitatively demonstrated that the activation barriers between these non-AA sites are significantly lower than those associated with AA sites. Furthermore, MLIP-MD simulations of collective Li-ion diffusion in a realistic large-scale turbostratic graphite model showed that the continuously distributed AB and bridge sites form a percolation network that facilitates high-rate diffusion. The resulting diffusion coefficient of 1.05×10−6 cm2 s−1 at 300 K is almost three orders of magnitude higher than the values for conventional graphite, while the activation energy is as low as 172 meV (16.6 kJ mol−1), which is significantly lower than that of conventional graphite. These findings indicate that the moiré structural periodicity in turbostratic graphite creates a "highway network" for Li-ion transport, providing a quantitative explanation for the outstanding rate performance of turbostratic graphite anodes.

Due to the lack of long-range ordered structures, non-graphitic carbon materials are difficult to characterize using well-established diffraction techniques. Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, which does not rely on material crystallinity, provides an effective method for probing the local electronic structure of amorphous materials. However, NEXAFS exhibits significant angular dependence—while this enables the determination of chemical bond orientation, it also complicates direct spectral comparison between different samples. The classical magic angle method can decouple this angular dependence, but its applicability is strictly limited to systems with threefold or higher rotational symmetry, making it unsuitable for non-graphitic carbons with lower symmetry. To address this limitation, this work develops a universally applicable analytical approach—the "equivalent magic angle spectrum" method—and systematically establishes a complete, reproducible paradigm encompassing data pre-processing, deconvolution, intrinsic intensity extraction, and equivalent magic angle spectrum construction. The method is first validated on highly oriented pyrolytic graphite, a high-symmetry model material, by comparing the results with those obtained from the classical magic angle method. Subsequently, it is applied to a typical amorphous material system, successfully elucidating the evolution of the electronic structure of phenolic resin-derived non-graphitic carbons.

Developing carbon fiber reinforced polymer (CFRP) with efficient electrothermal functionality is essential in mitigating surface icing issues on critical infrastructure. To this end, embedding carbon nanotube (CNT) interleaves enables multifunctional CFRPs that integrate electrothermal deicing and interlaminar toughening. However, practical implementations face two major challenges: the loss of CNTs’ intrinsic properties during macroscopic assembly and the degradation of CNT assemblies’ electrothermal performance during composite fabrication. Here, a synergistic strategy was presented. First, aligned continuous CNT fiber films (CNTFs) were embedded as electrothermal layers to ensure the continuity of the conductive network. The obtained CNTF/CFRPs exhibit uniform electrothermal behavior at low voltage (≤ 10 V), with a surface equilibrium temperature of approximately 200 °C. Second, a solvent-assisted pre-impregnation locally enhanced the inter-fibre resin conductivity within the CNTFs via doping of discontinuous short CNTs (0.5~2 μm). With the establishment of a hierarchical CNT-CNTF conductive network, the electrothermal performance of the CNT-CNTF/CFRP composite was further enhanced. It raised the steady-state surface temperature by 120.5% and heats 55.2% faster on average within 300 s compared to CNTF/CFRP. Offering high electrothermal conversion efficiency along with the retained lightweight and thin characteristics of CFRP, this dual-scale synergistic strategy holds considerable potential for demanding applications.

The smooth and low specific surface area of conventional diamond materials severely limit their performance in surface-sensitive applications such as grinding/polishing, energy storage, and catalysis. Porous diamond materials with high surface area and self-sharpening capability have emerged as a frontier in diamond research. This study modified traditional metal-catalyzed etching techniques to construct interconnected porous structures on single-crystal diamond surfaces, featuring pore diameters (1-40 μm) and depths (50 μm), achieving a specific surface area of 82.63 m2/g. Raman spectroscopy and EDS analysis confirmed the preservation of diamond crystallinity and intrinsic properties during processing. The resultant porous boron-doped diamond (BDD) electrodes exhibited a remarkable specific capacitance of 58.65 mF/cm2, representing a 63.4-fold enhancement over pristine electrodes. The assembled pouch-type supercapacitor demonstrated a record-high energy density of 38.64 Wh/kg among diamond-based devices, coupled with a specific capacitance of 93 mF/cm2 and 92.7% capacitance retention over 10,000 cycles.

Sodium-ion batteries (SIBs) are promising energy storage devices for low-temperature applications. However, their practical application is limited by the lack of anode materials that combine structural stability with fast sodiation/desodiation kinetics. Here, we report N-doped carbon (NC)-wrapped Bi nanobeads embedded between graphite plates (designated as Bi-NC@G) as anode material for SIBs with high stability and remarkable low-temperature tolerance. In diglyme-based electrolytes, both Bi nanobeads and graphite plates store Na through a Na+-solvent co-intercalation mechanism, which allows to bypass Na+ desolvation and ensures fast sodiation/desodiation processes. The graphite plates and the NC layer function synergistically to enhance electrical conductivity, Na+ diffusion rate, and improve the structural stability of the material. Both Na||Bi-NC@G half-cells and Bi-NC@G||Na3V2(PO4)3 full cells exhibit exceptional electrochemical performance, with respect to rate capability (delivering 202.7 and 57.4 mAh g−1 at 20 A g−1, respectively), cycling stability (retaining 94.9% and 69.0% of their initial capacities after 10000 cycles at 5 A g−1, respectively), and low-temperature tolerance (maintaining 79.5% and 60.2% of their room-temperature capacities at −40 °C, respectively). Insights derived from this study can be applied to design advanced composite anode materials for the fabrication of highly stable SIBs operating in a wide temperature range.