Science Bulletin最新文献

The stable cycling of high-capacity electrode materials with substantial volume variations presents a persistent challenge, primarily attributed to structural instability and inefficient charge transport. Herein, inspired by the rambutan fruit's hierarchical structure, we propose a tri-layer composite architecture that synergistically optimizes strain relaxation and Li⁺ transport. The inner layer, typically vulnerable to severe strain and prolonged Li⁺ diffusion pathways, is composed of a Sn/Cr₂O₃/C nanocomposite with rapid (de)lithiation kinetics and moderate volume expansion. The intermediate layer, strategically designed for intrinsic strain accommodation and minimized lithium diffusion distance, features Si nanoparticles homogeneously dispersed within a conductive carbon matrix. The outmost layer comprises core-sheath-structured Sn@carbon nanotubes, establishing dual conductive pathways for both lithium ions and electrons. This design elegantly reconciles the high capacity of Si with large volume effect through strain relaxation. The resulting composite achieves an optimized equilibrium among strain accommodation, ion transport, and interfacial stability, ultimately leading to high capacity (1089 mAh g^-1 at 0.1 A g^-1) and stable cycling (580 mAh g^-1 after 700 cycles at 0.5 A g^-1).

The fundamental challenge in achieving high doping concentrations for multiple resonance emitters, while simultaneously suppressing Dexter energy transfer (DET)-induced concentration quenching, stems from their intrinsically long-lived exciton states. Moving beyond conventional steric hindrance strategies for intermolecular separation, we utilize terminal spirofluorene interactions to promote lamellar molecular stacking. This configuration enhances host-guest separation, achieving a Förster resonance energy transfer (FRET) radius of 3.19 nm, which effectively suppresses DET (with a DET rate constant: κ_DET = 3.48 × 10⁵ s^-1) while maintaining efficient FRET (with a FRET rate constant: κ_FRET = 1.59 × 10⁸ s^-1). This collective molecular orchestration breaks the concentration ceiling inherent to B/N-based systems without inducing spectral broadening (full-width-at-half-maximum, FWHM = 19/20 nm). As a proof of concept, our devices set new efficiency records for binary organic light-emitting diodes (OLEDs), reaching a peak external quantum efficiency (EQE) of 33.2% at 3%-5% doping in non-sensitized configurations and 36.9% with interlayer sensitization. This work introduces a materials design paradigm that successfully resolves the critical doping-concentration paradox in multiple resonance thermally activated delayed fluorescence (MR-TADF) systems, thereby enhancing their potential for commercial application.

Colloidal InAs quantum dots (CQDs) are promising materials for shortwave infrared (SWIR) optoelectronics because of their heavy-metal-free composition and tunable long-wavelength emission. However, achieving high-quality InAs CQDs with narrow linewidths and symmetric emission beyond 1500 nm remains challenging, primarily due to uncontrolled growth kinetics and surface defects during high-temperature synthesis. Here, we report a unified strategy that overcomes this synthesis-emission trade-off by integrating in situ HBr-assisted dual-site etching with a diffusion-dynamics-controlled continuous injection process. This approach stabilizes the nanoclusters and seeds simultaneously, suppresses secondary nucleation, and enables kinetically synchronized growth. Complementary density functional theory (DFT) calculations offer a mechanistic insight into the surface-driven growth modulation and confirm that Br^- treatment enhances facet-specific binding and suppresses mid-gap states. The resulting InAs CQDs exhibit symmetric single-peak emission centered at ∼1510 nm with an average diameter of ∼7.2 nm, narrow size distribution (coefficient of variation (C_V) = 11.5%), excitonic linewidths (half-width at half maximum (HWHM) < 70 meV), and long-term colloidal stability. These results redefine the synthetic framework for III-V CQDs and provide a scalable route for high-performance heavy-metal-free SWIR emitters.

Targeted drug delivery with spatiotemporal control is critical for potent cancer therapy, yet inadequate subcellular delivery remains a major obstacle for DNA-targeted therapeutics due to multiple intracellular barriers. Herein, we report a photo-responsive polyprodrug supramolecular assembly to yield self-accelerated subcellular delivery of therapeutic cargoes for synergistic photochemotherapy against triple-negative breast cancer. The designed polyprodrug bears cleavable camptothecin pendants via thioketal-carbonate linkers and co-assembles with amphiphilic photosensitizers into ultrasmall supramolecular assembly, thereby affording sustained cargo release and enhanced singlet oxygen generation due to J-aggregate engineering of the photosensitizer within the assembly. Upon near-infrared light irradiation, the assembly elicits light-programmable drug release and lysosomal membrane disruption to facilitate rapid drug cytosolic translocation, followed by increased nuclear envelope permeability through lamin B1 downregulation and lipid peroxidation, thereby accelerating the permeation of cytosolic cargoes into the nucleus. Consequently, the self-accelerated intranuclear accumulation results in the eradication of intractable tumor through synergistic photochemotherapy. This study demonstrates a chemically programmed strategy for spatiotemporally-controlled subcellular delivery, providing a feasible avenue for highly effective cancer therapy.

Optimizing the architecture of air electrodes is pivotal for improving reaction kinetics and structural stability in zinc-air batteries (ZABs), yet balancing these enhancements with cost-effective fabrication remains a challenge. Herein, a facile biomimetic assembly strategy is proposed to construct an asymmetric air electrode with Janus carbonaceous architecture and wettability gradient. Two components, which are functionalized graphene nanosheets (FGNSs) and carbon nanotubes (FCNTs) both anchoring iron phthalocyanine for oxygen reduction catalysis, are employed as building blocks. The former assemble into fish-scale-like hydrophilic lamellar structure facing the electrolyte, facilitating swift ion infiltration; while the latter arrange into waterspider-leg-like hydrophobic villus structure exposed to ambient air, enhancing rapid oxygen invasion. This asymmetric design (Asy-FCNTs-FGNSs) not only boosts mass transport and expands triple-phase boundary, but also improves structural robustness of the air electrode. The resulting ZAB achieves a high peak power density of 239.3 mW cm^-2 and a specific capacity of 814.3 mAh g_Zn^-1 (10 mA cm^-2), along with outstanding cycling stability, overwhelmingly outperforming conventional symmetric counterparts and prior self-supporting designs. This work presents an innovative architecture-optimization scheme for advanced air electrodes, offering a scalable bioinspired strategy to propel ZAB technology and guide future electrode advancements.

Atomically dispersed heterometal catalysts offer ultrahigh atomic utilization and defined heterointerfaces for superior catalytic performance compared to single-metal-site analogues, yet their precise atomic-level construction remains challenging. Herein, a structure-defined atomic-cluster catalyst (Pt_SANi_C/CNT) is synthesized via sequential atomic layer deposition (ALD). This strategy enables atomic-scale engineering of Pt surface exposure and electronic properties through controlled ALD cycles. The optimized Pt_SANi_C/CNT exhibits exceptional activity and durability for ammonia borane (AB) hydrolytic dehydrogenation, breaking the activity-stability trade-off with 9.6-fold and 1.4-fold higher activity than Pt_SA/CNT (single-atom) and Pt_SANi_SA/CNT (dual-atom) catalysts, respectively. Through in situ X-ray absorption spectroscopy, kinetic and dynamic analysis, and DFT calculations, we elucidate that Pt_SANi_C interfacial sites synergistically promote concurrent H₂O adsorption-dissociation and H₂ desorption. Mechanistic studies reveal that nickel clusters facilitate H₂O activation while Pt single atoms favor B-H bond cleavage due to an upshifted d-band center. This interfacial synergy also enhances selective hydrogenation and O₂/H₂O₂-involved oxidation. The ALD-based atomic engineering approach provides a generalizable route to construct efficient and durable heterometal catalysts with defined active sites.