Science China Materials最新文献

Electrocatalytic nitrate reduction reaction is considered as a promising and sustainable method for ammonia synthesis. However, the selectivity and yield rate of ammonia are limited by the competitive hydrogen evolution reaction and the complex eight-electron transfer process. Herein, we developed a (FeCoNiCu)Ox/CeO₂ polymetallic oxide electrocatalyst for effective nitrate reduction to ammonia. The synergistic effects among the multiple elements in the electrocatalyst were clearly elucidated by comprehensive experiments. Specifically, Cu acted as the active site for reducing nitrate to nitrite, and Co facilitated the subsequent reduction of nitrite to ammonia, while Fe and Ni promoted water dissociation to provide protons. Furthermore, the incorporation of CeO₂ increased the active surface area of (FeCoNiCu)Ox, resulting in an improved ammonia yield rate to meet industrial demands. Consequently, the (FeCoNiCu)Ox/CeO₂ electrocatalyst achieved an ammonia current density of 382 mA cm⁻² and a high ammonia yield rate of 30.3 mg h⁻¹ cm⁻² with a long-term stability. This work offers valuable insights for the future design of highly efficient multi-element electrocatalysts.

J-aggregates of cyanine have shown great merits in tumor photothermal therapy (PTT) due to their distinct redshift absorption as well as superior photothermal conversion efficiency (PCE). However, due to the complexity of intermolecular interactions, especially the impact of steric hindrance on aggregation, exploring effective strategies to regulate the aggregation modes of organic materials remains challenging. Herein, steric hindrance-regulated J-aggregation of near-infrared (NIR) cyanine was reported based on Pt-coordinated cyanine self-assembly with unexpected “butterfly effect”. Two Pt-coordinated cyanine dimers CyR-Pt (R = Me and Et) were synthesized and spontaneously self-assembled into aggregates in aqueous solution. CyEt-Pt aggregates were loose and amorphous stacking. By replacing ethyl with methyl to reduce steric hindrance, a tiny change resulted in the generation of tightly stacked cyanine J-aggregates (thickness less than 3 nm) observed in CyMe-Pt self-assembly. Significantly, this unexpected “butterfly effect” enabled CyMe-Pt J-aggregates to effectively inhibit reactive oxygen species and greatly improve its photostability. Besides, CyMe-Pt J-aggregates with NIR-II absorption exhibited outstanding photothermal stability and higher PCE (η = 37%) than CyEt-Pt disordered aggregates (η = 20%). Evident tumor suppression performance of CyMe-Pt J-aggregates was validated under 980 nm laser irradiation, demonstrating its great potential in tumor PTT.

Aqueous metal-H₂O₂ cells are emerging as power batteries because of their large theoretical energy densities and multiple application scenarios, especially in underwater environments. However, the peak power densities are less than 300 mW cm⁻² for most reported metal-H₂O₂ cells based on Mg/Al or their alloys due to the self-corrosion. Herein, we reported a Zn-H₂O₂ cell with ultrafine bean-pod-like ZnCo/N-doped electrocatalysts that were synthesized via multifunctional single-cell-chain biomass. The electrocatalyst provides abundant active sites on the crinkly interface and offers a shortened pathway for electron/ion transfer due to the desired root-like carbon nanotube (CNT) arrays. Therefore, the optimized electrocatalyst exhibited outstanding oxygen reduction reaction (ORR) activity, with high E_1/2 (0.90 V) and E_onset (1.01 V) values. More importantly, Zn-H₂O₂ batteries achieve a record-breaking peak-power density of 510 mW cm⁻² and a high specific energy density of 953 Wh kg⁻¹.

Perovskite nanocrystal (PNC) solids are promising materials for optoelectronic applications. Recent studies have shown that exciton diffusion in PNC solids occurs via alternate exciton hopping (EH) and photon recycling (PR). The energy disorder induced by the size distribution is a common factor in PNC solids, and the impact of this energy disorder on the exciton diffusion remains unclear. Here, we investigated the exciton diffusion in CsPbBr₃ NC solids with a Gaussian size distribution of 11.2 ± 6.8 nm via steady and time-resolved photoluminescence (PL) spectroscopy with multiple detection bands in transmission mode. Our results indicated that exciton diffusion was controlled by a downhill transfer among the different energy sites through the disordered energy landscape, as confirmed by the accompanying low-temperature PL analysis. A detailed examination revealed that the acceptor distribution in tandem with the reabsorption coefficient determined the contribution of EH and PR to exciton transfer between different energy sites. Consequently, the exciton diffusion mechanism varied in PNC solids of different thicknesses: in a thin solid with a thickness of several hundred nanometers, the exciton transfer was dominated by efficient EH and PR from the high-energy sites to the lower-energy sites; in a few-micrometer-thick solid, transfer from the medium-energy sites toward the lower-energy sites also became prominent and occurred mainly through PR. These findings enhance the understanding of the vital role that the acceptor distribution plays in the exciton diffusion process in PNC solids, providing important insights for optoelectronic applications based on PNC solids. Our work also exploits the use of commonly available tools for in-depth exciton diffusion studies, which reveals the interior diffusion information that is usually hidden in surface sensitive PL imaging methods.

Clearing senescent cells (SnCs) have emerged as a promising strategy for delaying aging and treating aging-related diseases. The combined administration of dasatinib and quercetin has been widely employed for the elimination of SnCs. However, the therapeutic effectiveness of these two drugs is restricted because they possess distinct pharmacokinetics and biodistributions in vivo. Hence, there is a pressing need to devise a strategy for the targeted synchronous delivery of these two drugs. Here, a dual-drug codelivery nanosystem (lysozyme-dasatinib and quercetin nanoparticles, L-DQ) was developed by integrating DQ through electrostatic interactions. Furthermore, the surfaces of these nanoparticles were modified with lysozyme, enhancing their ability to specifically target the kidney for efficient clearance of SnCs. Through in vivo and in vitro experiments, the effective elimination of SnCs from the kidney and accelerated recovery of renal function by L-DQ were demonstrated. This study provides a potential strategy for the treatment of multiple aging-related diseases by the targeted delivery of senolytics to specific organs.

Efficient multi-resonance thermally activated delayed fluorescence (MR-TADF) materials hold significant potential for applications in organic light-emitting diodes (OLEDs) and ultra-high-definition displays. However, the stringent synthesis conditions and low yields typically associated with these materials pose substantial challenges for their practical applications. In this study, we introduce an innovative strategy that involves peripheral modification with sulfur and selenium atoms for two materials, CFDBNS and CFDBNSe. This approach enables a directed one-shot borylation process, achieving synthesis yields of 66% and 25%, respectively, while also enhancing reverse intersystem crossing rates. Both emitters exhibit ultra-narrowband sky-blue emissions centered around 474 nm, with full width at half maximum (FWHM) values as narrow as 19 nm in dilute toluene solutions, along with high photoluminescence quantum yields of 98% and 99% in doped films, respectively. The OLEDs based on CFDBNS and CFDBNSe display sky-blue emissions with peaks at 476 and 477 nm and exceptionally slender FWHM values of 23 nm. Furthermore, the devices demonstrate remarkable performances, achieving maximum external quantum efficiencies of 24.1% and 27.2%. This work presents a novel and straightforward approach for the incorporation of heavy atoms, facilitating the rapid construction of efficient MR-TADF materials for OLEDs.

We report a photothermally-induced liquid-solid/gas-solid-decoupling photocatalytic water-splitting system, where a carbonized melamine foam (CMF) and a porous g-C₃N₄ (PCN) serve as the photothermal substrate and model photocatalyst, respectively. Specifically, liquid water is transformed into the gaseous phase over the CMF due to the photothermal effect, and the generated vapor can be split into hydrogen by PCN via the photocatalysis. This unique biphasic photocatalytic system exhibits a high hydrogen production rate of 368.1 µmol h⁻¹, which is 2.4 and 25.6 times larger than those of the traditional triphasic PCN system (151.7 µmol h⁻¹) and g-C₃N₄ (CN) system (14.4 µmol h⁻¹), respectively. The improved photocatalytic performance is mainly attributed to the optimized energy and mass transfer at the gas-liquid-solid reaction interface, where gas products are rapidly desorbed in the photocatalytic process. This work provides a novel strategy to enhance the photocatalytic performance from the perspectives of energy and mass flow.

Rare earth elements (REEs) are essential raw materials vital for the advancement of modern high-tech industries. However, their extraction often leads to environmental concerns. The similar chemical properties of REEs contribute to high energy consumption and significant pollution emissions during the separation process. To address these challenges and promote sustainable development and efficient resource utilization, synthetic biology techniques have been leveraged to engineer microorganisms for rare earth fabrication. Establishing an engineered microorganism manufacture platform allows for the in-situ synthesis of high-value rare earth biomaterials. This innovation not only supports clinical translational research but also enhances applications in cutting-edge fields. This article offers a comprehensive review of the rational construction of rare earth cell factories, the synthesis of high-value rare earth biomaterials, and their diverse applications in high-tech industries. Moreover, it examines the perspectives and challenges within the domain of lanthanide materials fabrication using microbial systems.

V₂O₅, which has multicolor and energy storage properties, is a promising electrochromic material for multifunctional electrochromic devices, but its practical application is limited by its poor lifespan and long switching time. In this work, high-performance V₂O₅/TiO₂ films were fabricated by spraying a V₂O₅ solution on in situ-grown TiO₂ nanorods. Due to the porous structure formed between the TiO₂ nanorods and the remarkable electron transfer performance of TiO₂, the switching time of the V₂O₅/TiO₂ films decreased. Moreover, the strong adhesion between the TiO₂ nanorods and F-doped tin oxide (FTO) glass and the increased surface roughness of the substrates significantly improved the cycling stability of the V₂O₅/TiO₂ films. With a large transmittance modulation (47.8% at 668 nm), fast response speed (τ_c = 5.1 s, τ_b = 4.2 s), and long lifespan, V₂O₅/TiO₂ films were used as electrodes for the electrochromic energy storage device (EESD), which switched in six colors through color overlay: dark orange, sandy yellow, green-yellow, yellow-green, dark green, and dark brown. Inspired by pixel displays, EESDs were designed by segmenting V₂O₅ films to stagger the display of the electrochromic and ion storage layers, which presented 11 types of information based on different combinations of colors. This work provides inspiration for developing multifunctional electrochromic devices, especially for camouflage and information displays.