SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4202-3
Carbon dots (CDs) with absorption in the second near-infrared window (NIR-II, 900-1700 nm) hold promise for tumor theranostics, yet existing synthesis methods often involve complex procedures, harsh conditions, or lack precise control. Here we report a 'self-photooxidation-restructuring' strategy that enables structural reorganization of the carbon core in CDs, achieving a significant redshift of absorption into the NIR-II region. Under ultraviolet (UV) light irradiation, the precursor (B-CDs, absorption in UV region) generates singlet oxygen, which self-oxidizes aldehyde groups and the carbon skeleton of B-CDs to stronger electron-withdrawing carboxyl groups and carbon radicals, respectively. These processes facilitate the formation of new C=C bonds between isolated aromatic domains, thereby transforming B-CDs into novel CDs (N-CDs) characterized by enhanced donor-acceptor interactions and a redshift in absorption toward the NIR-II window. Various experimental data, including high-resolution XPS, FTIR, NMR, EPR, have proved the proposed formation mechanism. The novel N-CDs afforded a high photothermal conversion efficiency of up to 71.33%, which enabled 1064 nm laser-activated photoacoustic imaging (PAI)-guided photothermal therapy (PTT) in tumors. This work opens a new avenue for the synthesis and modulation of CDs in the NIR-II region.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4203-7
The solution process holds great promise for organic light-emitting diode (OLED) fabrication owing to its minimal material loss, simple processing and low equipment investment. However, solution-processed blue OLEDs still face the challenges of low electroluminescence efficiency and poor working stability. In this study, two new cross-linkable blue light-emitting molecules, v-4CzBn and v-5CzBn, were synthesized. They featured a multicarbazole-substituted benzonitrile donor–acceptor structure as the emitting core, with two vinyl phenyl units on the carbazole rings serving as cross-linking groups. A singlet–triplet energy gap of ΔEST ≤ 0.10 eV and a high reverse intersystem crossing rate (kRISC > 10^6 s−1) were achieved because the three-dimensionally confined covalent network structure formed through a thermal cross-linking reaction limited intramolecular motions and vibrational relaxations of luminescent units. Moreover, this structure suppressed irreversible morphological changes and structural deterioration of light-emitting units due to aggregation or crystallization, improving the light-emitting performance of the device. Nondoped solution-processed OLEDs with the structure of ITO/PEDOT:PSS/TFB/S-4CzBn/TPBi/LiF/Al exhibited blue emission with a peak at 488 nm, achieving a maximum external quantum efficiency of 12.01%, a maximum luminance of 11,141.15 cd m−2, and a T50 lifetime of 1375.66 h@100 cd m−2. This result represents the longest operational lifetime reported to date for solution-process devices with cross-linked emitting layers.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3793-9
Organic solar cells (OSCs) require both a high donor/acceptor (D/A) interfacial area for efficient exciton dissociation and a vertically phase-separated morphology for efficient charge transport. Traditional bulk heterojunctions (BHJs) provide large interfacial areas but lack vertical phase separation, while quasi-planar heterojunctions (QPHJs) achieve vertical separation at the cost of reduced interfacial contact. Here, we introduce an in situ pore-forming strategy for polymer thin films. By incorporating an excess of additives as pore-forming agents into the donor layer, a nanoporous film with a fibrous nano-network is generated. Subsequent deposition of acceptor molecules fills these nanopores, creating a hybrid planar/bulk heterojunction (HP/BHJ) that synergizes the strengths of both architectures. This design enhances performance by: (1) increasing the D/A interfacial area via nanopores, forming a three-dimensional network that accelerates exciton dissociation; (2) promoting close molecular packing that minimizes carrier recombination and establishes low-defect charge transport channels; and (3) fostering vertical phase separation through layer-by-layer deposition. Binary OSCs fabricated with this strategy achieve a power conversion efficiency (PCE) of 20.0%, surpassing conventional BHJ and QPHJ devices by a significant margin. The approach demonstrates general applicability, with analogous improvements observed in D18/BTP-eC9-4F and PM6/L8-BO systems, underscoring its potential for advancing OSC performance.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3616-8
Negative stiffness (NS) structures exploit multi-stable mechanisms to achieve energy absorption, yet their practical application is limited by material and manufacturing constraints that compromise load-bearing capacity, reusability, and energy absorption efficiency. This study addresses these limitations by employing continuous carbon fiber reinforced thermoplastic polymers (CCFRTP) and three-dimensional (3D) printing to fabricate NS structures with cosine beam cells. A wet twisting method for continuous carbon fiber (CCF) was developed to enhance mechanical properties and elucidate failure behaviors and interfacial adhesion mechanisms. The resulting CCF/PLA/PVDF composites exhibited significant improvements in mechanical properties compared to untreated counterparts, with failure analysis revealing characteristic fiber breakage due to enhanced interfacial adhesion, as opposed to fiber pull-out and irregular fracture in untreated samples. A one-stroke path planning model was used to investigate bistability principles and energy absorption mechanisms. Displacement-controlled loading/unloading experiments assessed energy absorption in both energy-locked and repetitive modes. A dual-unit assembly structure was fabricated to validate the feasibility of a negative stiffness honeycomb structure. Composite layup simulations via Abaqus confirmed the deformation process and energy absorption mechanisms. The findings demonstrate that CCFRTP-based NS structures offer considerable potential for large deformation energy absorption applications in aerospace and naval fields.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3816-y
Tool protective films operate under extreme service conditions, requiring exceptional hardness. Transition metal diborides (TMB2), with strong covalent TM–B and B–B bonds, are promising candidates, but achieving superhardness while preserving their simple binary structure remains challenging. Here, we use HfB2 as a model system to reveal how boron vacancy filling and in-plane compressive stress synergistically enhance hardness, through combined experimental synthesis and first-principles calculations. (001)-oriented HfB2 thin films were fabricated, including sub-stoichiometric HfB2−x, stoichiometric HfB2, and stoichiometric HfB2 under compressive stress. Nanoindentation shows the hardness increases from 33.0 ± 1.1 GPa in HfB1.90 to 40.5 ± 0.4 GPa in stoichiometric HfB2, and further to 45.7 ± 1.1 GPa under −3.67 GPa stress. Calculations reveal that vacancy filling increases the number of load-bearing bonds and strengthens B–B bonding via charge accumulation, while compressive stress shortens B–B bonds to further enhance their strength. These findings clarify the atomic-scale mechanisms of vacancy and stress engineering in TMB2, and propose a simple, scalable pathway to superhard protective films without alloying or doping, addressing a long-standing challenge in coatings for extreme environments.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3973-9
Circularly polarized luminescence (CPL) is a phenomenon where chiral molecules emit light with distinct left or right circular polarizations upon excitation. Unlike conventional luminescent materials, chiral materials produce light with inherent helicity, leading to unique applications in chiral optoelectronics, quantum technologies, and biophotonics. This review systematically explores the theoretical and computational foundations of CPL, focusing on the interplay between molecular chirality, transition dipole moments, and photoluminescence quantum yield. A major challenge in designing efficient CPL-active materials is optimizing the luminescence dissymmetry factor (g_lum) while maintaining high photoluminescence efficiency. This review comprehensively summarizes how first-principles computational methods, by establishing robust predictive frameworks, have significantly advanced the design of CPL molecules. Even though significant progress has been made in modeling monomeric systems, the effective integration of first-principles calculations to describe CPL in aggregated states remains an ongoing challenge. The review also highlights the promising synergy between computational models, experimental validation, and emerging data-driven techniques such as machine learning (ML) for guiding the design of novel high-performance CPL materials. In conclusion, further research is needed to overcome current computational limitations and develop more effective strategies for CPL material design.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202512042
Chlorinated volatile organic compounds (CVOCs) such as dichloromethane (DCM), dichloroethane (DCE), trichloroethylene (TCE), and chlorobenzene (CB) are hazardous air pollutants requiring efficient removal. This study modified a commercial activated carbon (AC) via high-temperature treatment and phenol cracking carbon deposition to tailor its pore structure for enhanced adsorption of small-molecule CVOCs. The modified material (AC-M) exhibited a significant increase in ultramicropore volume (<0.8 nm), leading to a 24.2% increase in DCM adsorption capacity under dry conditions and superior water vapor resistance. Surface oxygen-containing functional groups decreased, enhancing hydrophobicity and mitigating water cluster formation. Adsorption kinetics analysis revealed that AC-M had a 39% higher total adsorption rate constant for DCM and a 22% reduction in mass transfer zone height, indicating faster adsorption. However, for larger CVOCs (DCE, TCE, CB), adsorption capacities slightly decreased due to reduced specific surface area, suggesting their adsorption relies more on micropores of matching size. This work provides a theoretical basis for designing efficient adsorbents for small-molecule CVOCs control.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511050
Municipal solid waste (MSW) management in Inner Mongolia has long relied on landfilling, facing land scarcity and leachate management challenges. This study addresses the region's dry, cold climate, high proportion of agricultural and livestock waste, fluctuating moisture content, and weak leachate treatment capacity. An engineering optimization was implemented on an 80 t·d−1 vertical rotary gasification-incineration system featuring a dual-combustion-chamber design (primary chamber for medium-temperature pyrolysis-gasification at 550–650 °C and secondary chamber for high-temperature oxidation above 900 °C), coupled with in-situ leachate recirculation. Field measurements showed improved processing capacity and continuous operation stability. Under the project's leachate yield, in-situ recirculation achieved on-site disposal without significant adverse effects on gasification-incineration conditions, providing buffering against moisture fluctuations. During the monitoring period, major gaseous pollutant emissions remained below current national standards. The results provide engineering references for the co-processing and stable operation of small-scale county-level MSW treatment facilities.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4109-2
The fabrication of high-efficiency organic solar cells (OSCs) under ambient conditions remains a formidable challenge due to the sensitivity of active layer morphology to environmental factors. We propose an innovative approach for air-processed devices that combines spontaneous water-spreading film formation with layer-by-layer (LBL) deposition. This method enables the fabrication of donor- and acceptor-dominant bulk heterojunction blend films near the anode and cathode interfacial layers, respectively, optimizing vertical phase separation and enhancing charge transfer efficiency. In the D18:L8-BO system, the device achieves a power conversion efficiency (PCE) of 19.02% with an exceptionally narrow efficiency distribution. Even for devices with an area of 1 cm2, a PCE of 16.56% is attained. After a 1000-hour decay test, the efficiency retains 84.1%. This novel method offers a promising pathway for advancing the industrial application of large-area, highly stable devices with narrow efficiency distribution under ambient conditions.