Latest ArticlesThe efficient energy conversion of fuel cells is greatly constrained by the slow oxygen reduction reaction (ORR) kinetics, which necessitates the use of highly active metal catalysts such as platinum (Pt). The critical challenge limiting large-scale usage of Pt is the capital cost that can be addressed through a prototypical approach by embedding metal nanoparticles (NPs), e.g., Pt NPs, in the conductive framework. However, previously reported embedding approaches are sophisticated and suffer from limited yields, leading to higher chemical process costs and remaining distant from commercial viability. Here, we report a facile, cost-effective and time-efficient structural tuning approach to synthesizing ultrafine Pt NPs impregnated within a conductive and highly porous carbon framework via a microwave-assisted polyol reduction method. Pt NPs with a uniform size of ~2.27 nm can be successfully integrated within the pores of the carbon framework, enabling homogeneous dispersion. Benefiting from these highly dispersed and ultrafine Pt NPs, the electrochemical surface area (ECSA) is improved to 142.98 m²/gPt, 2.25 times higher than that of the commercial counterpart (63.52 m²/gPt). Furthermore, our structurally optimized catalyst composite features a remarkably catalytic activity with a high half-wave potential (E1/2) of 0.895 V and an improved mass activity (MA) of 0.2289 A/mgPt, 2.39-fold improvement compared to the commercial counterpart. In addition, orthogonal experiments were designed to identify the key process parameters for fabricating Pt/C catalysts, offering insights for scaled-up and industrial production.
Defects at the surface and grain boundaries of the perovskite films are extremely detrimental to both the efficiency and stability of perovskite solar cells (PSCs). Herein, a simple and stable quaternary ammonium halide, named chlormequat chloride (i.e., chlorinated choline chloride, CCC), is introduced to regulate the upper surface chemical environment of perovskite films. The anion (Cl−) and cation [ClCH2CH2N(CH3)3]+ in CCC could effectively self-search and passivate positively and negatively charged ionic defects in perovskites, respectively, which contributes to inhibited nonradiative recombination and reduced energy loss in PSCs. As a result, the champion power conversion efficiency (PCE) of PSCs can be significantly enhanced from 22.82% to 24.07%. Moreover, the unencapsulated device with CCC modification retains 92.0% of its original PCE even subject to thermal aging at 85 ℃ for 2496 h. This work provides guidance for the rational design of functional molecules as defect passivators in PSCs, which is beneficial for the improvements in both device performance and stability.
Zinc metal is regarded as one of the most promising anodes for Zn-based batteries in next-generation energy storage systems. However, the dendrite growth and interfacial corrosion lead to poor reversibility and cycle life of Zn anodes. Herein, we synthesize a 2-phosphate-1,2,4-butane tricarboxylic acid modified hyperbranched polyamidoamine containing rich terminal groups of phosphate and carboxyl (HPC) as modified layer for the Zn anodes. Importantly, the in situ acid-etching promotes the exposure of (002)Zn plane and the generated salt-polymer complexes could be adhered to the Zn anodes tightly. This greatly favors the uniform deposition of Zn and inhibits interfacial corrosion. Consequently, stable HPC@Zn anode plating/stripping for over 1200 h at a high areal capacity of 4 mAh/cm2 and a current density of 4 mA/cm2 is obtained. This study provides a new avenue of hyperbranched polymer in interfacial design for highly reversible and stable Zn metal anodes.
Carbon dots (CDs), as a solid-state phosphor, have great potential for application in a new solid-state lighting device—laser diode (LD). For high efficiency LD devices, both high photoluminescence quantum yield (PLQY) and high photothermal stability of CDs are essential. Herein, yellow CDs@ZIF-8 composites with high structural stability were prepared by encapsulating CDs in zeolitic imidazolate framework-8 (ZIF-8) through electrostatic adsorption between CDs and ZIF-8, in which CDs with amino groups on the surface were used as luminescent feeders and ZIF-8 was used as a protective layer matrix. The as-prepared CDs@ZIF-8 not only possess a high PLQY of up to 81.17%, but also maintain a high fluorescence intensity of 100% and 80% under long-term illumination (60 min) and high temperature (478 K), respectively. The hydrogen bonding between CDs and ZIF-8 in the encapsulated structure can enhance the degree of electron cloud delocalization, which can improve the PLQY of CDs@ZIF-8. Meanwhile, CDs@ZIF-8 has high photothermal stability due to the binding effect of ZIF-8 on CDs and high thermal stability of ZIF-8. The white LD device, fabricated from CDs@ZIF-8 as a phosphor in combination with 450 nm blue LD, has a color coordinate of (0.37, 0.33), a color temperature of 3762 K, and a high color rendering index of 86. This study provides a new strategy for the construction of solid-state phosphors with high PLQY and high photothermal performance.
Natural hydrogels have emerged as a pivotal innovation in wound care, offering a unique combination of high absorbency, biocompatibility, and versatility. However, due to the complexity of wound healing, the physiological state of the wound varies dynamically, and the mechanism of natural hydrogels that boost wound healing is still unclear. In this review, we firstly provide a comprehensive introduction to the biological process of wound healing, emphasizing the critical stages and factors affecting healing. This work concludes the composition and properties of natural hydrogels, including collagen, gelatin, hyaluronic acid, chitosan, alginates, cellulose, and fibroin, highlighting their biocompatibility and biodegradability. The focus shifts to the various crosslinking strategies employed to enhance the structural integrity and functionality of natural hydrogels. This review further investigates the biological effects of natural hydrogels in wound healing, detailing their antibacterial, antioxidant, anti-inflammatory, adhesive, and hemostatic functions. Furthermore, we propose the challenges and future perspectives of natural hydrogels in practical applications. This review offers a comprehensive overview of the current state and potential future advancements in natural hydrogel dressings for wound care, highlighting their critical role in addressing complex and hard-to-heal wounds.
Spin-orbit, charge-transfer intersystem crossing (SOCT-ISC) can directly overcome the disadvantages of the traditional heavy-atom effect and improve the generation efficiency of reactive oxygen species (ROS). Since orthogonal molecular orbitals of donor-acceptor (D-A) pairs favor the SOCT-ISC transition, herein aza-borondipyrromethenes (aza-BODIPYs) with 1,7-di-anthracyl groups (An-azaBDP) was successfully prepared, owing to steric hindrance to produce a big dihedral angle between the two molecular orbital (MO) planes. Moreover, according to density functional theory (DFT) and time-dependent density functional theory (TDDFT), the energy difference between the S1-T1 orbitals of An-azaBDP is small and more inclined towards ISC. An-azaBDP can effectively generate singlet oxygen under light irradiation. An-azaBDP with light irradiation can induce apoptosis in SW620 cells, and can serve as a potential candidate for the treatment of cancer cells and tumors.
Solid polymer electrolytes (SPEs) are considered to be one of the most promising systems applied in all-solid-state lithium metal batteries (ASSLMBs) on account of their chemical and electrochemical robustness, mechanical stability, cost-effective and scalable manufacturing techniques. Lately, significant endeavors have been directed towards mitigating the formation of the Li dendrite in SPE-based ASSLMBs, while research on the inactive lithium in the forms of the solid-electrolyte interface has been rarely reported. Herein, a bi-functional GaI3 additive is developed for in-situ generating Li3Ga alloy for suppressing Li dendrite growth, as well as I3− in recovering dead lithium. Relying on the density functional theory (DFT) results, the Li atom prefers to deposit on the Li3Ga surface and then guide uniform Li deposition, while the I3 species features a relatively lower lowest unoccupied molecular orbital (LUMO) energy level (-2.12 eV), meaning a higher electron affinity, which is beneficial for reviving inactive lithium to counterbalance the loss of lithium. As a result, in comparison to cells employing pure PEGDME-based electrolytes, the Li-Li symmetric cells utilizing GaI3-containing solid-state electrolyte exhibited a cycling life nearly 30 times longer at a current density/capacity of 0.2 mA/cm2, 0.2 mAh/cm2. The full batteries of LFP//1%GaI3-SPE//40 µm Li delivered a noteworthy capacity retention of 82% after 1300 cycles at a rate of 1 C.
The occurrence of acquired resistance to cisplatin (DDP) that induces the toxic drug effects has always been a huge challenge and urgently needs to be resolved in the cancer treatment. The combination of anticancer drugs with different mechanisms can remarkably improve the chemotherapeutic efficiency. Given that glutathione (GSH) plays as the driving factors in the resistance of DDP, here we have firstly proposed a “three birds, one stone” based nanoplatform to achieve triple synergetic effects simultaneously addressing DDP resistance in non-small cell lung cancer (NSCLC). Specifically, we initially designed and synthesized a DDP prodrug [Pt(Ⅳ)] bridged silsesquioxane precursor (Pt-Si). Then Pt-Si and bis[3-(triethoxysilyl)propyl]diselenide (BTESePD) were integrated into the framework of mesoporous organosilica nanoparticles (MONs) to obtain a nanocarrier MONPt/Se. After loading with norcantharidin (NCTD) and modifying with the aptamer AS1411 based G-quadruplex (Apt), the Apt@NCTD@MONPt/Se exhibit impressive tumor homing capability. Once being endocytosed, (Ⅰ) the diselenide and -O-Pt(Ⅳ)-O- rich scaffold can be reduced by the excessive GSH, followed by (Ⅱ) breaking the redox homeostasis via GSH depletion and precise release of the DDP. Next, the encapsulated NCTD is also released along with the degradation of the nanocarriers thereby (Ⅲ) achieving the GSH depletion and synergistic anti-tumor effect of NCTD and DDP. Taken together, we believe this “one stone, three birds” strategy may be a promising paradigm to conquer drug resistance for clinical care.
Hidden natural products are representative of defensive strategies produced in vivo in diseased plants, a process that is induced by the plant immune system. The first transcriptome library of uninfected and pathogen infected Hibiscus tiliaceus stems was constructed by transcriptome sequencing technology, genes related to cadinene-type sesquiterpenoid biosynthesis were screened and combined with ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS) analysis data, which indicated pathological tissue had potential to produce novel carbon skeletons of cadinane sesquiterpenoid dimers. Successfully, two cadinane-derived sesquiterpenoid dimers with unprecedented carbon skeletons, hibisceusanols A (1) and B (2) were isolated for the first time from the stems of H. tiliaceus induced by plant-microbial interactions. Their structures and absolute configurations were unambiguously established by spectroscopy, advanced chemistry development (ACD) and electronic circular dichroism (ECD) methods. Compounds 1 and 2 exhibited significant antitumor activity in vitro with half maximal inhibitory concentration (IC50) values of 2.3–7.2 µmol/L. The anticancer effect was generated via the induction of HepG2 cell apoptosis by inhibiting the phosphatidylinositol 3-kinase (PI3K) pathway.
Clinical phototheranostic agents suffer from low absorption in near-infrared (NIR) region, decreasing singlet oxygen quantum yield (1O2 QY) caused by aggregation in water, and low photothermal conversion efficiency (PCE), all of which are factors weakening their phototheranostic efficacy. Herein, we designed and synthesized a donor-acceptor-donor (D-A-D) structured boron-dipyrromethene derivative (B-2TPA) which exhibited NIR absorption and fluorescence. After being encapsulated in amphiphilic distearoyl phosphoethanolamine polyethyleneglycol 2000 (DSPE-PEG-2000), the water-soluble B-2TPA nanoparticles (NPs) had increasing 1O2 QY (6.7%) due to the intermolecular aggregation-induced decrease in the energy gap between singlet and triplet excited states. Moreover, the quenched fluorescence and stable twisted intramolecular charge transfer in aggregates further increased the PCE of B-2TPA NPs to 60.1%. In vitro and in vivo studies confirmed that B-2TPA NPs could be used in NIR fluorescence and photoacoustic imaging-guided synergistic photodynamic and photothermal therapy in tumor treatment.