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Phenylhydroxylamine and its derivates (PHAs) are important chemical intermediates. Phenylhydroxylamines are mainly produced via the catalytic reduction of aromatic nitro compounds. However, this catalytic reduction method prefers to generate thermodynamically stable aromatic amine. Thus, designing suitable catalytic systems, especially catalysts to selectively convert aromatic nitro compounds to PHAs, has received increasing attention but remains challenging. In this review, we initially provide a brief overview of the various strategies employed for the synthesis of PHAs, focusing on reducing aromatic nitro compounds. Subsequently, an in-depth analysis is presented on the catalytic reduction process, encompassing discussions on catalysts, reductants, hydrogen sources, and a comprehensive assessment of the merits and drawbacks of various catalytic systems. Furthermore, a concise overview is provided regarding the progress made in comprehending the mechanisms involved in this process of catalytic reduction of aromatic nitro compounds. Finally, the main challenges and prospects in PHAs’ production via catalytic reduction are outlined.

Highlights2D Sn nanosheets (SnNSs) were prepared through the combination of cryogenic exfoliation and liquid-phase exfoliation.The functionalized 2D SnNSs have good stability, superior biocompatibility, high photothermal conversion efficiency, and multimode imaging capability.Stanene (Sn)-based materials have been extensively applied in industrial production and daily life, but their potential biomedical application remains largely unexplored, which is due to the absence of the appropriate and effective methods for fabricating Sn-based biomaterials. Herein, we explored a new approach combining cryogenic exfoliation and liquid-phase exfoliation to successfully manufacture two-dimensional (2D) Sn nanosheets (SnNSs). The obtained SnNSs exhibited a typical sheet-like structure with an average size of ~ 100 nm and a thickness of ~ 5.1 nm. After PEGylation, the resulting PEGylated SnNSs (SnNSs@PEG) exhibited good stability, superior biocompatibility, and excellent photothermal performance, which could serve as robust photothermal agents for multi-modal imaging (fluorescence/photoacoustic/photothermal imaging)-guided photothermal elimination of cancer. Furthermore, we also used first-principles density functional theory calculations to investigate the photothermal mechanism of SnNSs, revealing that the free electrons in upper and lower layers of SnNSs contribute to the conversion of the photo to thermal. This work not only introduces a new approach to fabricate 2D SnNSs but also establishes the SnNSs-based nanomedicines for photonic cancer theranostics. This new type of SnNSs with great potential in the field of nanomedicines may spur a wave of developing Sn-based biological materials to benefit biomedical applications.

Lithium–sulfur battery has been considered as a promising electrochemical energy storage system based on its theoretical energy density. However, its practical application is hindered by poor conductivity of sulfur and the shuttle effect. Herein, a hierarchical three-dimensional nitrogen and phosphorous codoped graphene and carbon nanotubes with 70 wt% of sulfur content (N, P codoped G/CNTs-S70) composite was prepared using melamine phosphate as a single precursor of N and P. The simultaneous introduction of N and P creates high active sites on the G/CNTs backbones, restricts the detachments of sulfur from the host G/CNTs, and induces strong chemical adsorption of the dissolution of lithium polysulfides. The as-prepared N, P codoped G/CNTs-S70 composite delivers a high initial discharge capacity of 1550 mA h g −1  and retains a capacity of 735 mA h g −1  after 200 cycles at 0.5  C. This is a significant improvement in the rate capability and cycling stability compared with the un-doped G/CNTs-S70 cathode. This simple strategy with single precursor offers promising electrochemical properties for Li–S batteries.

HighlightsAn artificial macrophage with hierarchical nanostructure (BaSO4@ZIF-8/TRF NMΦ) is constructed as an alternative to immunoactive macrophages.The Zn2+ chemical messenger as an “artificial cytokine” is released from the artificial macrophage to induce tumor anoikis and enhance immunogenicity.The artificial macrophage can efficiently capture tumor antigens for antigen presentation and T cell activation to fabricate long-term antitumor immunity, successfully mimicking the basic functions of natural immunoactive macrophage.Artificial cells are constructed from synthetic materials to imitate the biological functions of natural cells. By virtue of nanoengineering techniques, artificial cells with designed biomimetic functions provide alternatives to natural cells, showing vast potential for biomedical applications. Especially in cancer treatment, the deficiency of immunoactive macrophages results in tumor progression and immune resistance. To overcome the limitation, a BaSO4@ZIF-8/transferrin (TRF) nanomacrophage (NMΦ) is herein constructed as an alternative to immunoactive macrophages. Alike to natural immunoactive macrophages, NMΦ is stably retained in tumors through the specific affinity of TRF to tumor cells. Zn2+ as an “artificial cytokine” is then released from the ZIF-8 layer of NMΦ under tumor microenvironment. Similar as proinflammatory cytokines, Zn2+ can trigger cell anoikis to expose tumor antigens, which are selectively captured by the BaSO4 cavities. Therefore, the hierarchical nanostructure of NMΦs allows them to mediate immunogenic death of tumor cells and subsequent antigen capture for T cell activation to fabricate long-term antitumor immunity. As a proof-of-concept, the NMΦ mimics the biological functions of macrophage, including tumor residence, cytokine release, antigen capture and immune activation, which is hopeful to provide a paradigm for the design and biomedical applications of artificial cells.

Manganese dioxide (MnO 2 )-based nanomaterials can be used as sulfur host, improving the cycle stability by inhibiting the shuttle effects of polysulfide through chemisorption with the polar host. In this work, we design a novel soft template synthesis of acetylene black and MnO 2 nanosheets (AB/MnO 2 ) composites by simple and cost-effective methodology. The AB/MnO 2 was used as a highly efficient sulfur host for advanced lithium–sulfur batteries. The cheap and highly conductive AB facilitates fast electron transport. The polar host, MnO 2 nanosheets, provides chemical interactions and efficiently impedes the dissolution of polysulfide. Accordingly, the cathodes AB/MnO 2 –S (4:1) and AB/MnO 2 –S (1:1) with 67 and 70 wt% sulfur content deliver the initial discharge specific capacity of 1326 and 1113 mA h g −1 at the current density of 837.5 mA g −1 (0.5 C), respectively. Particularly, the AB/MnO 2 –S (1:1) cathode shows the most stable coulombic efficiency and cyclability compared with AB/S cathode after 200 cycles. In addition, the AB/MnO 2 –S (4:1) cathode exhibits a capacity of 1071 mA h g −1 at the current density of 1675 mA g –1 (1 C). Along with this green and cost-effective protocol of synthesis, we expect that the AB/MnO 2 composites have potential application in advanced Li–S batteries.

The lithium–sulfur (Li–S) batteries are promising because of the high energy density, low cost, and natural abundance of sulfur material. Li–S batteries have suffered from severe capacity fading and poor cyclability, resulting in low sulfur utilization. Herein, S-DHCS/CNTs are synthesized by integration of a double-hollow carbon sphere (DHCS) with carbon nanotubes (CNTs), and the addition of sulfur in DHCS by melt impregnations. The proposed S-DHCS/CNTs can effectively confine sulfur and physically suppress the diffusion of polysulfides within the double-hollow structures. CNTs act as a conductive agent. S-DHCS/CNTs maintain the volume variations and accommodate high sulfur content 73 wt%. The designed S-DHCS/CNTs electrode with high sulfur loading (3.3 mg cm−2) and high areal capacity (5.6 mAh mg cm−2) shows a high initial specific capacity of 1709 mAh g−1 and maintains a reversible capacity of 730 mAh g−1 after 48 cycles at 0.2 C with high coulombic efficiency (100%). This work offers a fascinating strategy to design carbon-based material for high-performance lithium–sulfur batteries.

Sn-based anode materials have gained more attention for application in lithium-ion batteries (LIBs), due to tin having the characteristics of high specific capacity, low cost, and environmentally friendly. However, low capacity retention due to the large volume changes upon lithiation/delithiation limits their further development. In this paper, tin nanoparticle/3D framework carbon composite (denoted as Sn@SC) is obtained by calcining the composite of trisodium citrate and stannous sulfide. The Sn@SC composite delivers a stable cycling capacity of 410.9 mAh/g after 150 cycles and 300.1 mAh/g after 950 cycles at 1 A/g. The excellent electrochemical performance can be assigned to the fact that the hollow porous carbon can provide enough space for the volume change of tin nanoparticles in the step-by-step alloying process and shorten the electron transport path, thus increasing the structural stability and rate capability.

The paper describes a colorimetric sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of human IgG. It is based on the use of an Fe(II) coordination complex as a signal amplifier and of mesoporous silica nanoparticles modified with glucose oxidase (GOx) and secondary antibodies (Ab 2 ). After formation of the immuno sandwich complex, the quantity of GOx is proportional to the quantity of IgG. On addition of Fe(II) and glucose, GOx catalyzes the oxidation of glucose to produce hydrogen peroxide which oxidizes Fe(II) to Fe(III). After adding a stop solution containing the complexing ligand 1,10-phenanthroline (Phen), un-reacted Fe(II) forms an orange-red complex with Phen which can be detected by plate reader and even seen with bare eyes. This sandwich ELISA has a linear response in the 1 pg.mL −1 to 100 ng.mL −1 human IgG concentration range and a 860 fg.mL −1 detection limit. This is 20 times lower than the commercial ELISA for human IgG. The assay also is selective, stable, highly sensitive and cost-effective. Graphical abstract Schematic of a colorimetric enzyme-linked immunosorbent assay (ELISA) based on Fe(II) coordination complex as signal amplification strategy for human IgG detection. Glucose oxidase (GOx, green) and detection antibodies (Ab 2 , brown) functionalized mesoporous silica nanoparticles (MSN) were prepared as probe.

Diabetic wounds infected with methicillin-resistant (MRSA) are challenging to heal due to biofilm formation, which impairs conventional antibiotics with limited penetration and severe side effects. Near-infrared (NIR)-driven nanomotors with autonomous motion and photothermal effects show promise for antibacterial therapy but often lack targeted specificity. Lysostaphin (Ly), an enzyme targeting bacterial cell walls, offers excellent potential against drug-resistant MRSA. A novel NIR-driven CSIL nanomotor has fabricated by co-loading indocyanine green (ICG) and lysostaphin onto spinous yolk-shell structured C/SiO @C nanoparticles. The autonomous motion, biofilm penetration, and antibacterial efficacy of CSIL nanomotors are evaluated , while their biofilm eradication and wound healing performance are assessed in an MRSA-infected diabetic mouse model using a cascade photodynamic therapy (CPDT) strategy. CSIL nanomotors exhibit photothermal and photodynamic properties with MRSA-targeting specificity. They can effectively eradicate MRSA biofilms both and , suppress virulence and biofilm-related genes, thus promoting diabetic wound healing by shaping a microenvironment dominated by M2 macrophages. The CPDT strategy is able to avoid excessive ROS production and thermal damage, enabling safe and effective therapy. CSIL nanomotors, with integrated photothermal, photodynamic, and MRSA-targeting properties, represent a novel, efficient and targeted approach to antibacterial therapy in diabetic wounds, offering significant advantages over conventional antibiotics.

Carbon-supported single-atom catalysts were found to suffer reversible deactivation in catalytic hydrogenation, but the mechanism is still unclear. Herein, nitro compounds hydrogenation catalyzed by N-doped carbon-supported Co single atom (Co 1 /NC) was taken as a model to uncover the mechanism of the reversible deactivation phenomenon. Co 1 /NC exhibited moderate adsorption towards the substrate molecules (i.e., nitro compounds or related intermediates), which could be strengthened by the confinement effect from the porous structure. Consequently, substrate molecules tend to accumulate within the pore channel, especially micropores that host Co 1 , making it difficult for the reactants to access the active sites and finally leading to their deactivation. The situation could be even worse when the substrate molecules possess a large size. Nevertheless, the catalytic activity of Co 1 /NC could be restored via a simple thermal treatment, which could remove the adsorbates within the pore channel, hence releasing active sites that were originally inaccessible to reactants.