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.
Constructing a smart polymer film with favorable lithium (Li) transport capability and mechanical flexibility for suppressing Li dendrite growth is an effective strategy. Unfortunately, the porosity and the swelling of the polymer membrane cannot completely prevent liquid electrolyte from sweeping through the artificial protection film, severely deteriorating the cyclic performance. Herein, we propose a defect-free hybrid film that consists of Li+ conductive lithium polyacrylate (LiPAA) polymer interface layer and Li-Zn alloy patch to tackle the critical problems of traditional polymer composite passivation film. The pinhole leaks of the polymer matrix are self-filled by Li-Zn alloy patches, enhancing the integrity of LiPAA film. Consequently, a defect-free hybrid film is nailed flat against the Li metal anode, exhibiting extraordinary stability in the liquid electrolyte and enabling perfect protection effect. This facile strategy produces a promising anode for next generation Li batteries.
Aqueous alkaline zinc batteries (AZBs) exhibit great potential due to their high capacity, high safety and low cost. However, despite these advantages, the lack of high stability and high utilization rate makes the search for high-performance cathode materials a great challenge. Here, an amorphous nickel boride/rGO (NiB/rGO) complex structure was designed. As a result of abundant unsaturated active sites and synergistic electronic effects, amorphous NiB exhibits excellent energy storage properties. As well as having high electrical conductivity, rGO avoids aggregation of NiB nanoparticles, ensuring that NiB/rGO electrodes have a high energy storage capacity. The structure has a strong adhesion between NiB and rGO, which protects its stable structure and extends its life. More importantly, the NiB/rGO//Zn full battery shows remarkable capacity (228.4 mAh/g at 2 A/g), extraordinary cycle durability (93.7% retained after 1000 cycles) and strong energy density 399.7 Wh/kg, when coupled with NiB/rGO cathode. This work will also shed light on other nickel-zinc batteries in order to achieve super durability and capacity.
Foods are often contaminated by multiple foodborne pathogens, which threatens human health. In this work, we developed a microfluidic biosensor for multiplex immunoassay of foodborne bacteria with agitation driven by programmed audio signals. This agitation, powered by the vibration of a speaker cone during music playing, accelerated the mass transport in the incubation process to form bacterial complexes within 10 min. Immunoassay reagents of the two target bacteria (Escherichia coli O157:H7 and Salmonella typhimurium) were preloaded into the corresponding fore-vacuum storage chamber on the chip, and released to participate in the subsequent immune analysis process by piercing the chambers. All the detection processes were integrated into a single microfluidic chip and controlled by a smartphone through Bluetooth. Under selected conditions, wide linear ranges and low limits of detection (LODs < 2 CFU/mL) were obtained, and real food samples were successfully determined within 30 min. This biosensing method can be extended to wide-ranging applications by loading different recognizing reagents.
Polymeric carbon nitride (PCN) has garnered increasing attention as a metal-free photocatalyst with a suitable band gap. In efforts to enhance its photocatalytic performance, researchers have examined various PCN materials, including poly(heptazine imide) (PHI) and poly(triazine imide) (PTI), two isomers within the PCN family that exhibit distinct and superior photocatalytic activity compared to other forms. The challenge, however, lies in the common practice among researchers to categorize PHI and PTI along with other PCN types under the overarching term "g-C3N4, " which significantly impedes optimization efforts. The objective of this review is to provide comprehensive insights into the structural features, photoelectrochemical properties, and effective characterization methods employed for distinguishing between PHI and PTI materials. The review also summarizes various optimization strategies, such as crystallinity adjustments, defect engineering, morphology control, constructing heterojunction, and atomic-level metal loading dispersion, to elevate the photocatalytic activity of PHI and PTI, in addition to summarizing the history of carbon nitride development. Furthermore, this review highlights the primary applications of PHI and PTI, encompassing nitrogen fixation, biomass conversion, organic synthesis, CO2 reduction, pollutant degradation, H2O2 production, and photocatalytic water splitting. Lastly, the prospects and challenges associated with further advancing PHI and PTI are thoroughly examined.
A novel Ce-containing poly(tungstobismuthate) Cs18Na8H20[Ce3(H2O)10W8Bi4O28(B-α-BiW9 O33)4]2·64H2O (1) has been synthesized by a facile one-pot self-assembly reaction strategy. Its structural characterization is realized by virtue of single-crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction and thermogravimetric analysis. The polyoxoanion of 1 is an octameric architecture consisting of two tetrameric entities [Ce3(H2O)10W8Bi4O28(B-α-BiW9O33)4]23− linked by two CeOW bonds, and adjacent polyoxoanions are further combined together by means of Ce3+ linkers, resulting in an infinite 1D chain architecture. Compound 1 is the currently largest tungstobismuthate, and also represents the first example of lanthanide-encapsulated tungstobismuthate exhibiting an extended structure. Furthermore, compound 1 as a heterogeneous catalyst, exhibits high activity for the oxidative decontamination of a sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES) into 2-chloroethyl ethyl sulfoxide (CEESO).
Understanding the role of perovskite surface passivators in hot carriers transfer dynamics is important to develop highly efficient perovskite solar cells (PSCs). In this work, we have designed and synthesized a naphthalimide-based organic small molecule (NCN) for perovskite surface defect passivator. We reveal that the introduction of NCN not only reduces the density of perovskite defect-state, but also promotes hot carriers (HCs) cooling in perovskite through the transient absorption spectroscopy measurements. Fast HCs cooling permits HCs transfer from perovskite layer into NCN layer, thus resulting in the decreased charge-carrier recombination in NCN-treated device. As expected, the power conversion efficiency (PCE) of PSCs with NCN is enhanced to 22.02% from 19.95% for the control device. The findings are relevant for developing highly efficient PSCs.
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.
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.