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Rechargeable magnesium batteries (RMBs) are considered as potential energy storage devices due to their high volumetric specific capacity, good safety, as well as source abundance. Despite extensive efforts devoted to constructing an efficient magnesium battery system, the sluggish Mg

Rechargeable aluminum-ion batteries have attracted great attention due to the high theoretical volumetric capacity, good safety and abundant sources. Although tremendous efforts have been concentrated on exploring novel electrode materials for aluminum-ion batteries, the electrochemical mechanism still need to be further investigated. In this work, we found that even without employing any initial anode materials, the aluminum-ion batteries assembled with graphite cathode, AlCl3/ion liquid based electrolyte and various anodic current collectors still can be stably charged/discharged. A variety of carbon or metal based materials can be utilized as anodic current collectors in the initial-anode-free aluminum-ion batteries; however, their anti-corrosion capabilities against Cl− ions do greatly affect the battery performances. The electrochemical mechanism of initial-anode-free aluminum-ion batteries were comprehensively investigated by a series of in-situ and ex-situ spectroscopic and microscopic methods, revealing the reversible Al metal plating/stripping processes on the anodic current collectors during the charge-discharge cycles. We hope this work may provide new insights into the key component design and mechanism study of initial-anode-free multivalent secondary batteries.

Two-dimensional (2D) bismuthene material was predicted to possess intriguing physical and electrical properties, such as high-temperature quantum-spin Hall effect, topological edge state, high carrier mobility, and tunable band gap. However, epitaxial growth of single-crystalline 2D bismuthene nanoflakes inevitably requires a high vacuum environment, primarily due to the high surface energy constraints of Bi. Herein, we report the growth of 2D single-crystalline hexagonal bismuthene nanoflakes on Cu foil substrate at atmospheric pressure by chemical vapor deposition. Based on first-principles calculations, the structural transformation of Bi on Cu foil can be suppressed by introducing the top h-BN layer, which potentially compensates for the charge transfer from Bi to the Cu (1 1 1) surface. The sandwich structure is identified by cross-sectional SEM and EDS characterization, demonstrating that bismuthene nanoflakes are sandwiched between the h-BN film and Cu foil. Benefiting from the encapsulation of the top h-BN layer, bismuthene nanoflakes also exhibit excellent thermal stability in ambient air even after annealing at 500 °C for 10 min. For further practical application, bismuthene nanoflakes are utilized for electrochemical CO2 reduction reactions (CO2RR). These bismuthene nanoflakes demonstrate remarkable ability in converting CO2 to formic acid with a Faradaic efficiency of 96.3% at ‒1.0 V (vs. RHE) and exhibit great catalytic stability with a Faradaic efficiency of over 90% in 15 h CO2RR tests. The ultrathin 2D feature of as-prepared bismuthene nanoflakes may result in abundant CO2 adsorption sites and stabilize the intermediate *OCHO, finally favoring the formation of HCOOH. We provide an effective strategy to simultaneously synthesize and passivate 2D single-crystalline bismuthene nanoflakes towards CO2RR, which is expected to be applied to other 2D materials with strong metallic growth behavior.

Solar-powered CO2 conversion represents a promising green and sustainable approach for achieving a carbon-neutral economy. However, the rational design of a wide-spectrum sunlight-driven catalysis system for effective CO2 reduction is an ongoing challenge. Herein, we report the preparation of a rhodium/aluminum (Rh/Al) nanoantenna photothermal catalyst that can utilize a broad range of sunlight (from ultraviolet to the near-infrared region) for highly efficient CO2 methanation, achieving a high CH4 selectivity of nearly 100% and an unprecedented CH4 productivity of 550 mmol·g-1·h-1 under concentrated simulated solar irradiation (11.3 W·cm-2). Detailed control experiment results verified that the CO2 methanation process was facilitated by the localized surface plasmonic resonance and nanoantenna effects of the Rh/Al nanostructure under light irradiation. In operando temperature-programmed Fourier transform infrared spectroscopy confirmed that CO2 methanation on the Rh/Al nanoantenna catalyst was a multistep reaction with CO as a key intermediate. The design of a wide-spectrum solar-driven photothermal catalyst provides a feasible strategy for boosting CO2-to-fuel conversion.

Developing high-performance nitrogen reduction reaction (NRR) electrocatalysts is an ongoing challenge. Herein, we report a pyrolysis-free synthetic method for introducing ordered quasi-phthalocyanine N-coordinated transition metal (Ti, Cu, or Co) centers into a conjugated two-dimensional (2D) covalent organic framework (COF) for enhanced NRR performance. Detailed experiments and characterizations revealed that the NRR activity of Ti-COF was clearly better than that of Cu-COF and Co-COF, because of the superior abilities of Ti metal centers in activating inert N

Lithium-ion capacitor (LIC) has been regarded as a promising energy storage system with high powder density and high energy density. However, the kinetic mismatch between the anode and the cathode is a major issue to be solved. Here we report a high-performance asymmetric LIC based on oxygen-deficient black-TiO2-x/graphene (B-TiO2-x/G) aerogel anode and biomass derived microporous carbon cathode. Through a facile one-pot hydrothermal process, graphene nanosheets and oxygen-vacancy-rich porous B-TiO2-x nanosheets were self-assembled into three-dimensional (3D) interconnected B-TiO2-x/G aerogel. Owing to the rich active sites, high conductivity and fast kinetics, the B-TiO2-x/G aerogel exhibits remarkable reversible capacity, high rate capability and long cycle life when used as anode material for lithium ion storage. Moreover, density functional theory (DFT) calculation reveals that the incorporation of graphene nanosheets can reduce the energy barrier of Li+ diffusion in B-TiO2-x. The asymmetric LIC based on B-TiO2-x/G aerogel anode and naturally-abundant pine-needles derived microporous carbon (MPC) cathode work well within a large voltage window (1.0-4.0 V), and can deliver high energy density (166.4 Wh kg-1 at 200 mA g-1), and high power density (7.9 kW kg-1 at 17.1 Wh kg-1). Moreover, the LIC shows a high capacitance retention of 87% after 3,000 cycles at 2,000 mA g-1. The outstanding electrochemical performances indicate that the rationally-designed LICs have promising prospect to serve as advanced fast-charging energy storage devices.

Solar-driven photocatalytic overall water splitting is regarded as one of the ideal strategies to generate renewable hydrogen energy without the initiation of environmental issues. However, there are still a few remaining challenges to develop wide-light-absorption and stable photocatalysts for the simultaneous production of H2 and O2 in pure water without sacrificial reagents. Herein, we report the design and preparation of Z-scheme TiO2/ZnTe/Au nanocorncob heterojunctions by homogeneously decorating Au nanoparticles onto the surface of core–shell TiO2/ZnTe coaxial nanorods for highly efficient overall water splitting. With the appropriate band structure of TiO2/ZnTe heterojunctions and the surface plasmon resonance enhancement of Au nanoparticles, the well-designed TiO2/ZnTe/Au nanocorncob heterojunctions can synergistically make effective utilization of broad-range solar light illunimation and enhance the separation efficency of electron–hole pairs, as evidenced by UV-Vis absorption and time-resolved photoluminescence spectroscopy. Photoelectrochemical characterization confirms that the water-splitting reaction on TiO2/ZnTe/Au nanocorncobs is mainly carried out via a two-electron/two-electron transfer process with an intermediate product of H2O2. As a result, the TiO2/ZnTe/Au nanocorncob photocatalyst can generate H2 and O2 with a stoichiometric ratio of 2 : 1 under light irradiation without any sacrificial agents, exhibiting a high H2 production rate of 3344.0 μmol g−1 h−1 and a solar-to-hydrogen (STH) efficiency of 0.98%. Moreover, the TiO2/ZnTe/Au nanocorncob heterojunctions show high stability and well-preserved morphological integrity after long-term photocatalytic tests. This study provides a prototype route to produce clean hydrogen energy from only sunlight, pure water, and rationally-designed heterojunction photocatalysts.

Lithium–sulfur (Li–S) batteries with high theoretical energy density have caught enormous attention for electrochemical power source applications. However, the development of Li–S batteries is hindered by the electrochemical performance decay that resulted from low electrical conductivity of sulfur and serious shuttling effect of intermediate polysulfides. Moreover, the areal capacity is usually restricted by the low areal sulfur loadings (1.0–3.0 mg cm–2). When the areal sulfur loading increases to a practically accepted level above 3.0–5.0 mg cm–2, the areal capacity and cycling life tend to become inferior. Herein, we report an effective polysulfide mediator composed of nitrogen-doped carbon nanotube (N-CNT) forest planted on cobalt nanoflowers (N-CNTs/Co-NFs). The abundant pores in N-CNTs/Co-NFs can allow a high sulfur content (78 wt %) and block the dissolution/diffusion of polysulfides via physical confinement, and the Co nanoparticles and nitrogen heteroatoms (4.3 at. %) can enhance the polysulfide...

Sodium-ion batteries (SIBs) have been considered as one of the promising alternatives for lithium-ion batteries, owning to the abundant reserve and low cost of sodium-related salts. However, SIBs usually suffer from the sluggish kinetics of Na+ and the serious volume expansion of anode materials, which inevitably restrict the performance of SIBs. Herein, electroconductive wrinkled anatase-phase black titanium oxide nanosheets with rich oxygen vacancies (OVs-TiO2-x) was found to have an ultrafast Na+ insertion and extraction kinetics as anode material in SIBs. The wrinkled structure can significantly reduce the Na+ diffusion length, and the conductive networks formed by wrinkled OVs-TiO2-x can boost the electron transfer during Na+ insertion and extraction processes. With the rapid Na+ insertion/extraction ability, wrinkled OVs-TiO2-x delivers excellent sodium storage performance with high reversible capacity, ultra-high rate capability with the capacity reaches 91 mAh g−1 even at 20,000 mA g−1, and ultra-long cycling stability. These properties demonstrated the great potential of wrinkled OVs-TiO2-x to serve as a realistic choice of anode materials in SIBs.

Nanozyme is a collection of nanomaterials with enzyme-like activity but higher environmental tolerance and long-term stability than their natural counterparts. Improving the catalytic activity and expanding the category of nanozymes are prerequisites to complement or even supersede enzymes. However, the development of hydrolytic nanozymes is still challenged by diverse hydrolytic substrates and following complicated mechanisms. Here, two strategies are informed by data to screen and predict catalytic active sites of MOF (metal–organic framework) based hydrolytic nanozymes: (1) to increase the intrinsic activity by finely tuned Lewis acidity of the metal clusters; (2) to improve the density of active sites by shortening the length of ligands. Finally, as-obtained Ce-FMA-MOF-based hydrolytic nanozyme is capable of cleaving phosphate bonds, amide bonds, glycosidic bonds, and even their mixture, biofilms. This work provides a rational methodology to design hydrolytic nanozyme, enriches the diversity of nanozymes, and potentially sheds light on future evolution of enzyme engineering.

Nanozyme is a collection of nanomaterials with enzyme-like activity but exhibits higher environmental tolerance and long-term stability than their natural counterparts. Improving the catalytic activity and expanding the category of nanozymes are prerequisites to complement or even supersede natural enzymes. Specifically, a powerful hydrolytic nanozyme is demanded to degrade the unsustainable substance which natural enzymes hardly achieve. However, the development of hydrolytic nanozymes is still hindered by diverse hydrolytic substrates and following complicated mechanisms. Here, we apply two strategies which are informed by data to screen and predict catalytic active sites of MOF (metal–organic framework) based hydrolytic nanozymes. One is to increase the intrinsic activity by finely tuned Lewis acidity of the metal clusters. The other is to adjust the volume density of the active sites by shortening the length of ligands. Finally, we construct a Ce-FMA-MOF-based hydrolytic nanozyme with robust cleavage ability towards phosphate bonds, amide bonds, glycosidic bonds whose energy ascend in order; and even their mixture, biofilms. This work provides a rational methodology to design hydrolytic nanozyme, enriches the diversity of nanozymes, and potentially sheds a light on the evolution of enzyme engineering in the future.

Rechargeable aluminum-ion batteries (RAIBs) have attracted increasing attention owing to their high theoretical volumetric capacity, high resource abundance, and good safety performance. However, the existing RAIB systems usually exhibit relatively low specific capacities limited by the cathode materials. In this study, we developed a one-step chemical vapor deposition method to prepare single-crystal orthogonal Nb2O5 nanotubes for serving as high-performance electrode materials for RAIBs, showing a high reversible capability of 556 mA h g-1 at 25 mA g-1 and good thermal endurability at elevated temperatures (50 °C). A combination of a series of detailed ex situ structural characterization studies verified the reversible intercalation/deintercalation of chloroaluminate anions (AlCl4-) into/from the (001) planes of monocrystalline Nb2O5 nanotubes. It also revealed that the nanoarchitecture of Nb2O5 nanotubes with thin tube walls, hollow inner space and a short ion transport distance is conducive to the rapid kinetics of the insertion/extraction process. This work provides a promising route to design high-performance electrode materials based on transition metal compounds for RAIBs via the rational modulation of their structure and morphology.

Integrated energy “harvesting-storage” devices, especially photocharging devices that can simultaneously achieve the functions of photoelectric energy conversion and electrochemical energy storage, have attracted enormous attention to serve as sustainable and portable distributed power sources. However, the performance of photocharging devices is usually restricted by small voltage plateau and low energy conversion efficiency. Herein, we report a novel “solar capacitor” realized by combining a CsPbBr3 based all-inorganic perovskite solar cell (PSC) and an all-inorganic silica-gel-electrolyte based supercapacitor into a single device. Benefited from the synergy of these two components, the solar capacitor can simultaneously realize the functions of solar power harvesting and electrochemical energy storage without the aid of galvanostatic charging. This device has the merits of compact structure, very fast photocharging rate and high stability, exhibiting a record voltage plateau of 1.2 V and a remarkable overall “photo-electrochemical-electricity” energy conversion efficiency of 5.1%. This work provides new insights for designing novel energy conversion-storage integrated systems.

Hybrid lithium-ion capacitors (HLICs) have drawn great attention as promising energy devices, because they can integrate the high energy density of lithium ion batteries and the high power density of supercapacitors, and their low cost and long cycling-life are well suited to large-scale energy storage. However, the development of HLICs is usually limited by the kinetics mismatch between the battery-type anode and capacitor-type cathode. In this study, hierarchical Co3ZnC nanoparticle encapsulated mesoporous nitrogen-doped carbon nanopolyhedra (Co3ZnC@NC) synthesized by one-step pyrolysis of bimetallic-organic-frameworks are used as anode material for HLICs, exhibit high lithium storage capacity and excellent rate performance. Moreover, heteroatom-doped microporous carbon (MPC) derived from nature-abundant biomass (pine needles) are employed as cathode material, demonstrating good rate capability and long cycle stability. As a result, the as-prepared Co3ZnC@NC||MPC HLICs deliver high energy densities (up to 141.4 Wh kg−1), high power densities (up to 10.3 kW kg−1) and long cycle life within the wide operating voltage range (1.0–4.5 V). These encouraging results of the HLICs bridge the gap between supercapacitors and batteries, and show great potential in next-generation energy storage devices.

In the development of lithium-sulfur (Li-S) batteries, various approaches have been adopted to enhance the electronic conductivity of the sulfur cathode and alleviate the shuttle effect of polysulfides; however, the strategies providing efficient solutions are still limited. To further improve the electrochemical performance of Li-S batteries, in this work we propose a new strategy involving the incorporation of a three-dimensional functional spongy framework as polysulfide reservoir layer, with strong absorbability and electrocatalytic activity towards sulfur species. The spongy framework has a hierarchical architecture composed of highly conductive Ni foam/graphene/carbon nanotubes/MnO2 nanoflakes (NGCM). The strongly interconnected Ni foam, graphene, and carbon nanotubes of the NGCM sponge facilitate electron transfer during discharge/charge processes; moreover, the superlyophilic properties of the NGCM sponge ensure good wettability and interface contact with the Li-S electrolyte, and the porous MnO2 nanoflakes provide strong chemisorptive and electrocatalytic effects on polysulfides (as confirmed theoretically and experimentally). The NGCM sponge, serving as a polysulfide reservoir layer attached on a conventional sulfur-mixed carbon nanotubes (S/CNTs) cathode, can provide improved reversible capacity, rate capability (593 mAh·g–1 at 3.0 C), and cycling stability. In addition, the self-discharge rate is greatly reduced, owing to the efficient conservation of polysulfides in the NGCM spongy framework.

An efficient self-standing hydrogen evolution electrode was prepared by in situ growth of stacked ultrathin TiO2/MoS2 heterolayers on carbon paper (CP@TiO2@MoS2). Owing to the high overall conductivity, large electrochemical surface area and abundant active sites, this novel electrode exhibits an excellent performance for hydrogen evolution reaction (HER). Remarkably, the composite electrode shows a low Tafel slope of 41.7 mV/dec, and an ultrahigh cathodic current density of 550 mA/cm2 at a very low overpotential of 0.25 V. This work presents a new universal strategy for the construction of effective, durable, scalable, and inexpensive electrodes that can be extended to other electrocatalytic systems.

Overall water splitting driven by a sustainable solar energy source has been recognized as a promising route to produce clean and renewable hydrogen fuel. However, its practical application is restricted by the low energy conversion efficiency and poor stability of photocatalysts. Herein, we report the realization of highly efficient overall water splitting promoted by bifunctional bimetallic phosphide (Ni0.5Co0.5P) nanowire arrays vertically grown on carbon paper (Ni0.5Co0.5P/CP) and driven by highly stable all-inorganic perovskite solar cells (PSCs). The Ni0.5Co0.5P/CP electrocatalysts can provide abundant active sites, high electrical conductivity, and good contact interface with the electrolyte, thus showing remarkable activity and great durability for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The electrolyzer assembled with both the Ni0.5Co0.5P/CP anode and cathode can afford a current density of 10 mA cm−2 at only 1.61 V and allow consecutive water splitting. The all-inorganic PSCs based on a CsPb0.9Sn0.1IBr2 light absorber and a nanocarbon electrode exhibit remarkable stability. When driven by all-inorganic PSCs, the electrolyzer delivers a high overall energy conversion efficiency (3.12%) and good long-term durability.

Integrating energy harvesting devices with energy storage systems can realize a temporal buffer for local power generation and power consumption. In this manner, self-charging energy devices consisting of photovoltaic cells and energy storage units can serve as sustainable and portable distributed power sources that can concurrently generate and store electric energy without the need for external charging circuits. Herein, an integrated perovskite solar capacitor (IPSC) was realized by combining a perovskite solar cell (PSC) and a supercapacitor in a single device. Taking advantages of nanocarbon electrodes, the IPSCs possess a simple configuration, compact structure, and well-matched operation voltage. The IPSCs could be rapidly charged by different modes (including the photo-charging mode, galvanostatic-charging mode, and photoassisted-galvanostatic-charging mode), and showed a remarkable overall photo-chemical-electricity energy conversion efficiency as high as 7.1% in the photo-charging mode. Moreover, the IPSCs could work efficiently under weak light illumination. This study provides new insights for the design of novel integrative energy devices that combine the functions of solar power harvesting and electrochemical energy storage.

As emerging 2D materials, arsenene and arsenic materials have attracted rising interest in the past few years. The diverse crystalline phases, exotic electrical characteristics, and widespread applications of 2D arsenene and arsenic bring them great research value and utilization potential. Herein, the recent progress of 2D arsenene and arsenic is reviewed in terms of fundamental properties, preparation, and applications. The fundamental properties of 2D arsenene and arsenic, including the crystal phases, environmental stability, and electrical structure, from theoretical to experimental reports are first summarized. Then, the experimental processes for preparing 2D arsenene and arsenic, along with their respective advantages and disadvantages, are introduced including epitaxial growth, mechanical exfoliation, and liquid-phase exfoliation. Moreover, applications of 2D arsenene and arsenic are discussed, suggesting a wide range of applications of 2D arsenene and arsenic in field-effect transistors, sensors, catalysts, biological applications, and so on. Finally, some perspectives about the challenges and opportunities of promising 2D arsenene and arsenic are provided. This review provides a helpful guidance and stimulates more focus on future explorations and developments of 2D arsenene and arsenic.

Rechargeable silicon anode lithium ion batteries (SLIBs) have attracted tremendous attention because of their merits, including a high theoretical capacity, low working potential, and abundant natural sources. The past decade has witnessed significant developments in terms of extending the lifespan and maintaining high capacities of SLIBs. However, the detrimental issue of low initial Coulombic efficiency (ICE) toward SLIBs is causing more and more attention in recent years because ICE value is a core index in full battery design that profoundly determines the utilization of active materials and the weight of an assembled battery. Herein, a comprehensive review is presented of recent advances in solutions for improving ICE of SLIBs. From design perspectives, the strategies for boosting ICE of silicon anodes are systematically categorized into several aspects covering structure regulation, prelithiation, interfacial design, binder design, and electrolyte additives. The merits and challenges of various approaches are highlighted and discussed in detail, which provides valuable insights into the rational design and development of state-of-the-art techniques to deal with the deteriorative issue of low ICE of SLIBs. Furthermore, conclusions and future promising research prospects for lifting ICE of SLIBs are proposed at the end of the review.

Sodium-ion batteries (SIBs) are being increasingly studied due to their cost-effectiveness, high energy density and abundant resources. However, because of scanty interlayer spacing, commercial graphite-based materials that are currently used in lithium-ion batteries (LIBs) are not compatible for SIB anodes. Herein, we design a very convenient template strategy to synthesize spongy-like N, S-codoped ultrathin layered carbon assembly (NSLCA) with high N (9.5%) and S (1.7%) contents as an advanced anode material for SIBs. A petroleum-derived sulfur- containing pitch is chosen as the carbon skeleton, thus simplifying the preparation steps and reducing the costs. With the help of nanoporous MgO templates, the ultrathin layered carbon assembly can be facilely prepared. In addition, benefitting from the synergistic effects of codoped abundant N and S, as well as its unique assembly structures, the NSLCA anode exhibits outstanding sodium storage performance, with an especially superior rate performance (256 mA h g−1 at a current density of 3 A g−1) and a long lifespan (charge–discharge for as many as 2000 cycles with no capacity decay). This study provides a feasible and convenient strategy for the convenient and batch production of a spongy-like N, S-codoped carboneous material towards the construction of high-performance and cost-effectiveness SIBs.

Lithium−sulfur (Li−S) batteries are promising to replace current commercial Li−ion batteries due to the high energy density. Despite this, the poor cyclic stability induced by the shuttle effect of electrolyte-soluble intermediate polysulfides is one of the great obstacles for the application of Li−S batteries. To overcome this issue, here we report a self-template synthesis of metallic and polar Co 9 S 8 nanocrystals inlaid carbon (Co 9 S 8 /C) hollow nanopolyhedra as an efficient sulfur host material. The Co 9 S 8 /C hollow nanopolyhedra with large inner space can ensure the loading mass of sulfur and buffer the volume expansion of Li 2 S x species during cycling; while the metallic and polar Co 9 S 8 /C shell offers synergetic spatial confinement and chemical binding to immobilize polysulfides and prevent the shutting effect. The Co 9 S 8 /C-S composite cathode exhibits high capacity and long cycle life with a low capacity decay of 0.041% per cycle over 1000 cycles at 2.0 C. When the areal sulfur content is as high as 3.0 mg cm –2 , the Co 9 S 8 /C-S cathode still maintains high cycling stability.

Recently, Ni–based layered double hydroxide (LDH) materials have attracted growing interest owing to the remarkable performance for oxygen evolution reaction (OER). Here we demonstrate the preparation of ultrathin Ni3FeAlx trinary LDH nanosheets with higher activity and stability than NiFe–LDH nanosheets for OER. The enhancement was derived from Al substitution, which increased the concentration of Ni3+ active sites on the catalyst surface. Besides, low-coordinated Ni and Fe atoms and defects were formed by partial etching/dissolution of Al3+ in alkaline solution, which further increased the activity towards OER. To improve the conductivity, Ni3FeAlx–LDH (x=0, 0.91, 1.27 or 2.73) nanosheets were also in-situ grown on three-dimensional-networked nickel foam. The binder-free Ni3FeAlx–LDH/Ni foam electrodes exhibited further improved catalytic performance compared to the electrodes made of powdery Ni3FeAlx–LDHs and nafion binder. The best OER performance was presented by Ni3FeAl0.91–LDH/Ni foam, showing a Tafel slope of 57 mV/dec, a low overpotential (304 mV) at the current density of 20 mA/cm2, and a current density of 235 mA/cm2 at 1.60 V (vs. RHE). Furthermore, the Ni3FeAl0.91–LDHs/Ni foam electrode showed excellent long-term stability, maintaining a stable overpotential of 320 mV at 20 mA/cm2 after testing for 18 h.

Particulate matter (PM) pollution has become a serious environmental problem, especially in developing countries, owing to its severe threat to human health. Particularly, airborne PM 2.5 (mean aerodynamic diameter ≤2.5 µm) particles are extremely harmful, because the tiny particles can enter human respiratory system and even penetrate into circulatory system. Herein, we propose an effective strategy to recycle PM 2.5 carbon nanoparticles generated by diesel vehicle engine for the applications of clean energy. After thermal treatment and purification, the PM 2.5 derived carbon nanoparticles show a diameter distribution between 25 and 40 nm, mesoporous characteristics (with an average pore size of ~3.3 nm), and homogeneous nitrogen incorporation (with N content of ~1.1 at%). The PM 2.5 derived N-doped mesoporous carbon nanoparticles were used as an advanced electrode material in supercapacitors, exhibiting excellent specific capacity and superb stability over long-term cycling. Moreover, the recycled PM 2.5 carbon nanoparticles show attractive electrocatalytic properties for oxygen reduction reaction, presenting high onset potential and good immunity to methanol crossover. We expect this research can provide inspiration for air pollution control and sustainable energy utilization.

Although silver nanoparticles are considered as promising antibacterial agents because of their antibacterial activity, the acute cytotoxicity of Ag+ released from Ag nanoparticles restricts their potential practical applications. Herein, porous Ag@Au nanoplates, which could balance the Ag+ release and the toxicity of Ag naoparticles, were fabricated by stepwise seed-mediated growth and oxidation. Laser irradiation further boosted their antimicrobial activity, and significantly accelerated the curing rate of wound. Comparing with Ag nanoplates, the irradiated porous Ag@Au nanoplates showed the similar antibiotic ability against S. aureus strains and lower cytotoxicity in vitro. When the porous Ag@Au nanoplates were applied to treat S. aureus-infected wound, they had the best curing effect. Thus, these porous Ag@Au nanoplates could act as promising antibacterial agents for wound healing applications.