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J‐aggregation and H‐aggregation are identified as two classical models of functionally oriented non‐covalent interactions, and significant attention has been drawn by researchers. However, due to the scarcity of single‐crystal examples of H‐aggregation, a comprehensive understanding of the relationship between its stacking mode and optical behaviour has been hindered. In recent studies, two polyaromatic Schiff base compounds, Cl‐Salmphen and H‐Salmphen, were successfully synthesized, and both were found to exhibit H‐aggregation. In the findings, H‐Salmphen was shown to display typical C─H···π interactions, characteristic of Aggregation‐Induced Emission (AIE) active molecules, whereas its halogenated counterpart was identified as behaving similar to Aggregation‐Caused Quenching (ACQ) active molecules. These types of results suggest that identical intermolecular interactions can produce differing optical behaviours. Light was shed, at least in part, on the formation mechanisms of H‐type aggregates and their luminescence properties from these observations. Additionally, the high optical signal‐to‐noise ratio inherent to H‐aggregates was utilized for the exploration of water content detection. As an outcome, a high‐performance fluorescent filter paper was developed, enabling easy real‐time detection using a smartphone. [ABSTRACT FROM AUTHOR]

The development of environmentally sustainable and highly efficient technologies for ammonia production is crucial for the future advancement of carbon‐neutral energy systems. The nitrite reduction reaction (NO2RR) for generating NH3 is a promising alternative to the low‐efficiency nitrogen reduction reaction (NRR), owing to the low N=O bond energy and high solubility of nitrite. In this study, we designed a highly efficient dual‐atom catalyst with Fe‐Cu atomic pair sites (termed FeCu DAC), and the as‐developed FeCu DAC was able to afford a remarkable NH3 yield of 24,526 μg h−1 mgcat.−1 at −0.6 V, with a Faradaic Efficiency (FE) for NH3 production of 99.88 %. The FeCu DAC also exhibited exceptional catalytic activity and selectivity in a Zn‐NO2 battery, achieving a record‐breaking power density of 23.6 mW cm−2 and maximum NH3 FE of 92.23 % at 20 mA cm−2. Theoretical simulation demonstrated that the incorporation of the Cu atom changed the energy of the Fe 3d orbital and lowered the energy barrier, thereby accelerating the NO2RR. This study not only demonstrates the potential of galvanic nitrite‐based cells for expanding the field of Zn‐based batteries, but also provides fundamental interpretation for the synergistic effect in highly dispersed dual‐atom catalysts. [ABSTRACT FROM AUTHOR]

Water‐splitting reactions such as the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) typically require expensive noble metal‐based electrocatalysts. This has motivated researchers to develop novel, cost‐effective electrocatalytic systems. In this study, a new multicomponent nanocomposite was assembled by combining functionalized multiwalled carbon nanotubes, a Cu‐based metal–organic framework (MOF) (HKUST‐1 or HK), and a sulfidized NiMn‐layered double hydroxide (NiMn‐S). The resulting nanocomposite, abbreviated as MW/HK/NiMn‐S, features a unique architecture, high porosity, numerous electroactive Cu/Ni/Mn sites, fast charge transfer, excellent structural stability, and conductivity. At a current density of 10 mA cm−2, this dual‐function electrocatalyst shows remarkable performance, with ultralow overpotential values of 163 mV (OER) or 73 mV (HER), as well as low Tafel slopes (57 and 75 mV dec−1, respectively). Additionally, its high turnover frequency values (4.43 s−1 for OER; 3.96 s−1 for HER) are significantly superior to those of standard noble metal‐based Pt/C and IrO2 systems. The synergistic effect of the nanocomposite's different components is responsible for its enhanced electrocatalytic performance. A density functional theory study revealed that the multi‐interface and multicomponent heterostructure contribute to increased electrical conductivity and decreased energy barrier, resulting in superior electrocatalytic HER/OER activity. This study presents a novel vision for designing advanced electrocatalysts with superior performance in water splitting. Various composites have been utilized in water‐splitting applications. This study investigates the use of the MW/HK/NiMn‐S electrocatalyst for water splitting for the first time to indicate the synergistic effect between carbon‐based materials along with layered double hydroxide compounds and porous compounds of MOF. The unique features of each component in this composite can be an interesting topic in the field of water splitting. [ABSTRACT FROM AUTHOR]

The conversion of NO3−‐to‐NH3 by electrolysis is an appealing approach for wastewater treatment; however, such a process is hindered by the lack of efficient catalysts. Herein, taking the nanoporous Al11Ce3 intermetallic phase as an example, its electrocatalytic NO3− reduction reaction capability is first demonstrated. Benefiting from the unique structural feature, optimized intermediates adsorption and formation behavior, and restrained hydrogen evolution, the catalyst shows a remarkable electrochemical performance with a peak faradaic efficiency of 91 % and yield rate of 4.35 mg h−1 mgcat−1, along with robust activity over 30 h. Further, a Zn−NO3− battery by using Al11Ce3 as the cathode was designed, which gives a maximal power density of 8.5 mW cm−2 and a corresponding NH3 yield rate of 1.97 mg h−1 mgcat−1. [ABSTRACT FROM AUTHOR]

In this study, bowl‐shaped N‐doped hollow carbon sphere‐containing mesoporous nanomaterials (BNHC) were used for the ultrasensitive electrochemical detection of isoprenaline (ISOP). The linear ranges of the BNHC‐based sensor were as follows: 0.05 – 15 μM; 15 – 70 μM, with the limit of detection (LOD) of 6.8 nM. And the BNHC‐based electrochemical sensor showed a good current response to ISOP and maintained 95.6 % of the initial current after 30 days of storage. Notably, when the BNHC‐modified sensor was used to detect the actual ISOP injection and urine samples, the sensor exhibited satisfactory recovery. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the development of the textile and dye industry, a large amount of dye wastewater has been discharged. Semiconductor photocatalysis has been widely used in the treatment of environmental pollution, so it is very important to study efficient, nontoxic and stable photocatalysts. RESULTS: In this study, a microspherical activated carbon/Mn3O4/SrTiO3 composite photocatalyst with high catalytic activity was synthesized using sol–gel and chemical precipitation methods. The photocatalyst was characterized through X‐ray diffraction, scanning and transmission electron microscopy, energy dispersive spectroscopy, X‐ray photoelectron spectroscopy, photoluminescence, Electrochemical impedance spectroscopy, electron paramagnetic resonance spectroscopy and photocurrent measurements, and the effects of the initial methylene blue (MB) concentration and pH on the catalytic performance of the photocatalyst were investigated. The results revealed that the MC/Mn3O4/SrTiO3 composite has large light absorbance, and it can effectively inhibit photoinduced electron–hole pair recombination. The catalyst exhibited high photocatalytic degradation activity, and the degradation efficiency of MB at 300 ppm and pH 7 reached 99% after 80 min of UV light irradiation. The photodegradation process conformed to the pseudo‐first‐order kinetic model. Recyclability experiments showed that MC/Mn3O4/SrTiO3 composite has high stability, and the degradation rate of MB is > 70% after three repeat uses. CONCLUSIONS: This work provides a new method for finding low‐cost, high‐performance materials that can be modified and put into industrial use. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Combining morphological control engineering and diatomic coupling strategies, heteronuclear Fe-Co bimetals are efficiently intercalated into nitrogen-doped carbon materials with star-like to simultaneously accelerate oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The half-wave potential and kinetic current density of the ORR driven by FeCoNC/SL surpass the commercial Pt/C catalyst. The overpotential of OER is as low as 316 mV (/10), and the mass activity is at least 3.2 and 9.4 times that of mononuclear CoNC/SL and FeNC/SL, respectively. The power density and specific capacity of the Zn-air battery with FeCoNC/SL as air cathode are as high as 224.8 mW cm-2 and 803 mAh g-1, respectively. Morphologically, FeCoNC/SL endows more reactive sites and accelerates the process of oxygen reaction. Density functional theory reveals the active site of the heteronuclear diatomic, and the formation of FeCoN5C configuration can effectively tune the d-band center and electronic structure. The redistribution of electrons provides conditions for fast electron exchange, and the change of the center of the d-band avoids the strong adsorption of intermediate species to simultaneously take into account both ORR and OER and thus achieve high-performance Zn-air batteries. [ABSTRACT FROM AUTHOR]

The construction of high‐efficiency and low‐cost non‐noble metal bifunctional electrocatalysts for water electrolysis is crucial for commercial large‐scale application of hydrogen energy. Here, we report a novel strategy with erbium‐doped NiCoP nanowire arrays in situ grown on conductive nickel foam (Er‐NiCoP/NF). Significantly, the developed electrode shows exceptional bifunctional catalytic activity, which only requires overpotentials of 46 and 225 mV to afford a current density of 10 mA cm−2 for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively. Density functional theory calculations reveal that the appropriate Er incorporation into the NiCoP lattice can significantly modulate the electronic structure with the d‐band centers of Ni and Co atoms by shifting to lower energies with respect to the Fermi level, and optimize the Gibbs free energies of HER/OER intermediates, thereby accelerating water‐splitting kinetics. When assembled as a solar‐driven overall water‐splitting electrolyzer, the as‐prepared electrode shows a high and stable solar‐to‐hydrogen efficiency of 19.6%, indicating its potential for practical storage of intermittent energy. [ABSTRACT FROM AUTHOR]

Organic/silicon hybrid solar cells have attracted extensive attention owing to their low cost and simple manufacturing process. However, theoretical simulations indicate that the efficiency of organic/silicon hybrid solar cells should exceed 20%. This study demonstrates phosphorus and selenium co‐doped WO3 nanoparticles used for heterojunction solar cell (HSC) modification and theoretically elaborates the effects of these doping elements. The doped WO3 nanoparticles are added into poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) films to optimize the physical properties and qualities of the organic layer. The admixture of P/Se‐WOx greatly improves the open‐circuit voltage and fill factor of Si/PEDOT:PSS solar cell devices. In the hole transport layer (HTL)‐based device, the P/Se‐WOx hybrid PEDOT:PSS HTL yields a power conversion efficiency up to 13.64%, which is substantially higher than those of previously reported undoped and doped devices. The generated W5+ in optimized WO3 further indicates that the VI B group elements, such as W or Mo with 5+ state ions, positively influence the HSC performance and would greatly benefit the photovoltaic industry. [ABSTRACT FROM AUTHOR]

Over the past few decades, the design and development of carbon materials have occurred at a rapid pace. In particular, these porous graphene‐like carbon nitride materials have received considerable attention due to their superior structures and performances in the energy transformation field. In this review, nitrogenated holey two‐dimensional graphene and polymeric carbon nitride will be discussed in depth. The structural properties, synthetic methods, and applications including electrocatalytic reactions, such as hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, and nitrogen reduction reaction, will be presented in detail. Finally, we will present the outlooks on the current obstacles to the development of carbon nitride materials. This comprehensive understanding will help guide and motivate researchers to develop and modify carbon nitride materials with better properties in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: The occurrence of organic contaminants in surface water has drawn great concern in recent years. The construction of a heterostructure has been shown to improve photoactivity by boosting the separation of photogenerated charge carriers. In this work, magnetically separable NiFe2O4/Ag3VO4/Ag2VO2PO4 (NFO/AVO/AVPO) heterojunction photocatalysts were synthesized via a chemical etching method in ammonia solution of different concentrations, using NFO/AVPO as the source material. The magnetic NFO/AVO/AVPO not only endows magnetic recoverability using an external magnetic field, but also possesses a heterojunction, boosting the separation of photoinduced charges. RESULTS: Compared with NFO, AVPO and NFO/AVPO, NFO/AVO/AVPO composites as synthesized show improved visible‐light photoactivities. At the optimum concentration (0.15 mol L−1) of ammonia solution, the NFO/AVO/AVPO shows 8.5 and 10.7 times improved photodegradation efficiency for methylene blue and imidacloprid than that of pristine NFO/AVPO, respectively. Due to the presence of magnetic NiFe2O4, the NFO/AVO/AVPO can be magnetically separated easily from the photoreaction system using a magnet. The improved photoactivity can be attributed to the formation of a direct Z‐scheme heterojunction, which boosts the separation of photoinduced electron–hole pairs. CONCLUSION: This work not only opens up a new method to fabricate heterojunction photocatalysts, but also paves the way for designing advanced magnetically separable photocatalysts with improved photoactivity. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

BACKGROUND: Ordinary clay is a natural material with bulk volume that can potentially be used as a low‐cost support material for a catalyst after activation. RESULTS: In this study, ordinary clay was pretreated with NaOH and used as the support of a nickel catalyst. The treatment of the clay with NaOH significantly increased the mesopores, remarkably promoting the dispersion of Ni and enhancing the thermal stability of nickel by increasing the interaction of nickel with the support. In addition, the activation of the clay with NaOH created abundant alkaline sites and, correspondingly, reduced the acid sites on the catalyst surface. CONCLUSION: The presence of the alkaline sites suppressed the acetalization and etherification in the conversion of either furfural or vanillin in ethanol, making hydrogenation the dominant reaction route. The alkaline sites with an electron‐rich nature also suppressed the further hydrogenation of the furan ring in furfuryl alcohol with ethanol as the reaction medium. The nickel catalyst with the untreated clay as support did not have such an effect and the abundant acidic sites made the acetalization/etherification the competitive reactions of hydrogenation. The acidic/basic properties of the Ni/clay before and after the pretreatment with NaOH significantly impacted the reaction network in the hydrogenation reactions. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The fabrication of Zn‐CO2 batteries is a promising technique for CO2 fixation and energy storage. Herein, nitrogen‐doped ordered mesoporous carbon (NOMC) is adopted as a bifunctional metal‐free electrocatalyst for CO2 reduction and oxygen evolution reaction in the near‐neutral electrolyte. The ordered mesoporous structures and abundant N‐dopings of NOMC facilitate the accessibility and utilization of the active sites, which endow NOMC with excellent electrocatalysis performance and outstanding stability. Especially, a nearly 100% CO Faradaic efficiency is achieved at an ultralow overpotential of 360 mV for CO2 reduction. When constructed as an aqueous rechargeable Zn‐CO2 battery using NOMC as the cathode, it yields a high peak power density of 0.71 mW cm−2, a good cyclability of 300 cycles, and excellent energy efficiency of 52.8% at 1.0 mA cm−2. [ABSTRACT FROM AUTHOR]

Electrolytic water splitting using surplus electricity represents one of the most cost‐effective and promising strategies for hydrogen production. The high overpotential of the oxygen‐evolution reaction (OER) caused by the multi‐electron transfer process with a high chemical energy barrier, however, limits its competitiveness. Here, a highly active and stable OER electrocatalyst was designed through a cobalt‐induced intrastructural enhancement strategy combined with suitable electronic structure modulation. A carved carbon nanobox was embedded with tri‐metal phosphide from a uniform Ni−Co−Fe Prussian blue analogue (PBA) nanocube by sequential NH3 ⋅ H2O etching and thermal phosphorization. The sample exhibited an OER activity in an alkaline medium, reaching a current density of 10 mA cm−2 at an overpotential of 182 mV and displayed a small Tafel slope of 47 mV dec−1, superior to the most recently reported OER electrocatalysts. Moreover, it showed impressive electrocatalytic durability, increasing by approximately 2.7 % of operating voltage after 24 h of continuous testing. The excellent OER activity and stability are ascribed to a favorable transfer of mass and charge provided by the porous carbon shell, synergistic catalysis between the three‐component metal phosphides originating from appropriate electronic structure modulation, more exposed catalytic sites on the hollow structure, and chainmail catalysis resulting from the carbon protective layer. It is foreseen that this successfully demonstrated design concept can be easily extended to other heterogeneous catalyst designs. [ABSTRACT FROM AUTHOR]

Using hydrazine oxidation reaction (HzOR) to replace the oxygen evolution reaction is an effective way to decrease the overpotential of the anodic reaction in overall water splitting (OWS), facilitating cost‐effective and safe hydrogen production. Herein, Rh2S3/N‐doped carbon hybrids (Rh2S3/NC) are first reported as novel and efficient bifunctional electrocatalysts for hydrazine‐assisted hydrogen generation over a wide pH range. Specifically, Rh2S3/NC exhibits low overpotentials for the hydrogen evolution reaction (HER) in alkaline (38 mV), neutral (46 mV), and acidic (21 mV) electrolytes, to reach the current density of 10 mA cm−2, and maintains the activities over 70 h. Meanwhile, Rh2S3/NC also displays competitive HzOR performance at all‐pH electrolytes. Thus, serving as a bifunctional electrocatalyst for both HER and HzOR, Rh2S3/NC shows overwhelming‐Pt/C performance in three electrolytes, and can save over 93.3%, 85.2%, and 78.3% energy consumption compared to the corresponding OWS system. Moreover, theoretical calculations confirm that Rh2S3/NC owns low free‐energy changes of the H adsorption and the dehydrogenation of adsorbed NHNH both of which are beneficial to enhance catalytic activity. This work develops a novel bifunctional electrocatalyst with free pH‐dependent condition for the hydrazine‐assisted electrolysis system to furtherly reduce the cost of massive industrial H2 production. [ABSTRACT FROM AUTHOR]

Steric hindrance is an intrinsic issue for solid acid catalysts in catalyzing conversion of sugars with a certain size. Herein, the conversion of furfural and sugar monomers/oligomers over a heterogeneous catalyst (D008) and homogeneous acid (H2SO4) is conducted in aqueous medium. The results indicate the steric hindrance of D008 shows more significant effects on the conversion of the sugars than that of furfural, as the chain form of the sugar monomers/oligomers is much bigger than that of furfural in size. The high local concentration of hydrogen ions on D008 facilitates furfural polymerization via opening of the furan ring through hydration reactions. The deactivation of D008 is responsible for the low yield of volatile products when the polymer formed from the polymerization of the sugars fills the pores. The sugar structures determine the polymer's properties. Thermal stability of the coke derived from the sugar oligomers is lower than that from the sugar monomers due to more aliphatic structures in the resulting coke. In addition, the coke derived from the sugars is more hydrophilic than that from furfural, due to the multiple hydroxyl group in the sugar substrates. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) is of great importance in energy‐converting processes such as fuel cells and in metal–air batteries and is vital to facilitate the transition toward a nonfossil dependent society. The ORR has been associated with expensive noble metal catalysts that facilitate the O2 adsorption, dissociation, and subsequent electron transfer. Single‐ or few‐atom motifs based on earth‐abundant transition metals, such as Fe, Co, and Mo, combined with nonmetallic elements, such as P, S, and N, embedded in a carbon‐based matrix represent one of the most promising alternatives. Often these are referred to as single atom catalysts; however, the coordination number of the metal atom as well as the type and nearest neighbor configuration has a strong influence on the function of the active sites, and a more adequate term to describe them is metal‐coordinated motifs. Despite intense research, their function and catalytic mechanism still puzzle researchers. They are not molecular systems with discrete energy states; neither can they fully be described by theories that are adapted for heterogeneous bulk catalysts. Here, recent results on single‐ and few‐atom electrocatalyst motifs are reviewed with an emphasis on reports discussing the function and the mechanism of the active sites. [ABSTRACT FROM AUTHOR]

Developing highly active nonprecious‐metal catalysts for the oxygen reduction reaction (ORR) is of great significance for reducing the cost of fuel cells. 3D‐ordered porous structures could substantially improve the performance of the catalysts because of their excellent mass‐diffusion properties and high specific surface areas. Herein, ordered porous ZIF‐67 was prepared by forced molding of a polystyrene template, and Co‐supported, N‐doped, 3D‐ordered porous carbon (Co‐NOPC) was obtained after further carbonization. Co‐NOPC exhibited excellent performance for the ORR in an alkaline medium with a half‐wave potential of 0.86 V vs. reversible hydrogen electrode (RHE), which is higher than that of the state‐of‐the‐art Pt/C (0.85 V vs. RHE). Moreover, the substantially improved catalytic performance of Co‐NOPC compared with Co‐supported, N‐doped carbon revealed the key role of its hierarchical porosity in boosting the ORR. Co‐NOPC also exhibited a close‐to‐ideal four‐electron transfer path, long‐term durability, and resistance to methanol penetration, which make it promising for large‐scale application. [ABSTRACT FROM AUTHOR]

The low catalytic activity and poor mass transport capacity of platinum group metal free (PGM‐free) catalysts seriously restrict the application of proton‐exchange membrane fuel cells (PEMFCs). Catalysts derived from Fe‐doped ZIF‐8 could in theory be as active as Pt/C thanks to the high intrinsic activity of FeN4; however, the micropores fail to meet rapid mass transfer. Herein, an ordered hierarchical porous structure is introduced into Fe‐doped ZIF‐8 single crystals, which were subsequently carbonized to obtain an FeN4‐doped hierarchical ordered porous carbon (FeN4/HOPC) skeleton. The optimal catalyst FeN4/HOPC‐c‐1000 shows excellent performance with a half‐wave potential of 0.80 V in 0.5 m H2SO4 solution, only 20 mV lower than that of commercial Pt/C (0.82 V). In a real PEMFC, FeN4/HOPC‐c‐1000 exhibits significantly enhanced current density and power density relative to FeN4/C, which does not have an optimized pore structure, implying an efficient utilization of the active sites and enhanced mass transfer to promote the oxygen reduction reaction (ORR). [ABSTRACT FROM AUTHOR]

The article discusses the development of a new multicomponent nanocomposite, MW/HK/NiMn-S, for water splitting reactions. This nanocomposite is cost-effective and efficient, outperforming traditional noble metal-based electrocatalysts. The unique architecture, high porosity, and electroactive sites of the nanocomposite contribute to its enhanced electrocatalytic performance. The article suggests that further exploration of the nanocomposite's components could lead to exciting possibilities in the field of water splitting. [Extracted from the article]

In this study, a molybdenum disulfide/multiwalled carbon nanotubes (MoS2@MWCNTs) nanocomposite was synthesized by employing a simple hydrothermal method. The flower‐like structure of the MoS2@MWCNTs was characterized via scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the load of crystalline MoS2 was verified via X‐ray diffraction (XRD) and energy‐dispersive spectroscopy (EDS). The as‐prepared MoS2@MWCNTs nanocomposite was used to modify glassy carbon electrode (GCE) as an electrochemical sensor for detecting aristolochic acids (AAs). With the optimized parameters, the proposed electrochemical sensor exhibited good sensitivity and a broad linear concentration range for detecting AAs from 0.2 to 10 μmol/L and 10 to 100 μmol/L, with the sensitivity of −3.10 μA/(μmol/L) and −0.91 μA/(μmol/L), respectively. The detection limit was also calculated as 0.06 μmol/L (S/N=3) based on the low background signal. Furthermore, the modified electrochemical sensor exhibited good selectivity, repeatability, reproducibility, and stability, thus showing potential application for detecting AA in chinese herbs with good mean recovery and accuracy. In other words, the MoS2@MWCNTs/GCE can be used as an excellent platform to detect AAs. [ABSTRACT FROM AUTHOR]

Abstract: In this work, N‐doped hollow porous carbon spheres (N‐HPCSs) were synthesized by silicon dioxide template‐assisted polybenzoxazine (PB) coating strategy. The prepared N‐HPCSs have a smooth hollow ball structure surrounded by a well‐defined porous shell. Combining with in‐situ plating of Bi film, the N‐HPCSs were further fabricated a sensitive electrochemical platform for determination trace levels of Cd(II) by differential pulse anodic stripping voltammetry (DPASV). Under the optimized conditions, the Bi‐N‐HPCSs based sensor displays a linear response to Cd(II) over the range of 0.5 μg L−1 to 150 μg L−1. Meanwhile, the limit of detection (LOD, S/N=3) is estimated to be around 0.16 μg L−1 for Cd(II), which is 31 times lower than the safety values set by United States Environmental Protection Agency (EPA) for the drinking water. Moreover, the proposed method was successfully applied to detection of Cd(II) in tap water and lake water, and the analytical results of the presented method are agreed well with inductively coupled plasma‐mass spectrometry (ICP‐MS) data. Due to the excellent analytical performance, the fabricated electrode is promised for future development in monitoring of cadmium pollution in the environment. [ABSTRACT FROM AUTHOR]

Various advanced catalysts based on sulfur-doped Fe/N/C materials have recently been designed for the oxygen reduction reaction (ORR); however, the enhanced activity is still controversial and usually attributed to differences in the surface area, improved conductivity, or uncertain synergistic effects. Herein, a sulfur-doped Fe/N/C catalyst (denoted as Fe/SNC) was obtained by a template-sacrificing method. The incorporated sulfur gives a thiophene-like structure (C−S−C), reduces the electron localization around the Fe centers, improves the interaction with oxygenated species, and therefore facilitates the complete 4 e− ORR in acidic solution. Owing to these synergistic effects, the Fe/SNC catalyst exhibits much better ORR activity than the sulfur-free variant (Fe/NC) in 0.5 m H2SO4. [ABSTRACT FROM AUTHOR]

Mesoporous materials have exceptional properties for application owing to their ability to absorb and interact with guest species. A novel MgO/OMC composite with mesoporous structure was successfully synthesized via in situ magnesiothermic reduction. The structure was confirmed by N2 sorption isotherms, X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). By using nafion and bismuth films as co-modifiers, the MgO/OMC composite material shows high sensitivity of 0.113 mA·Lmg-1 and lower background current for electrochemical determination of lead ion (Pb2+) by using anodic stripping voltammetry. The high specific surface area and good mass transfer on the proposed mesoporous material, as well as the outstanding adsorption abilities of MgO to metal ions and the excellent conductivity of the carbon skeleton contribute to the enhanced electrochemical response of Pb2+. As the stripping response of Bi/ MgO/OMC-Nafion/PGE is highly linear (R2=0.998) over a Pb2+ concentration range of 2 to 300 μg/L, it was successfully used to analyse Pb2+ in real tap-water samples with good recoveries. [ABSTRACT FROM AUTHOR]

Many existing research focuses on the differences or performance comparisons between single‐atom or small‐sized nanocluster catalysts, but there is a lack of comprehensive research on the coupling relationship between the structure and activity and the mechanism of synergy. This study investigates the combined catalytic potential of cobalt single atoms (SAs) and nanoclusters (NCs) for enhanced peroxymonosulfate (PMS) activation to degrade norfloxacin (NFX). A novel CoSAs‐NCs/CN/TiO2 catalyst is synthesized, featuring cobalt SAs and NCs uniformly dispersed on the carbon film wrapping TiO2, and the degradation efficiency of the NFX solution is almost completely degraded, with a mineralization rate of 76.35%. Density functional theory (DFT) calculations indicate that the synergistic interaction between cobalt SAs and NCs promotes more efficient PMS adsorption and activation and significantly reduces the activation energy barrier, which enhances electron transfer and increases reactive oxygen species (ROS) generation. This research highlights the robust and versatile nature of this novel catalyst system in addressing various contaminants. This study elucidates the activation mechanism of catalysts, providing new ideas for advanced oxidation processes (AOPs) in environmental remediation, linking the structure and performance of catalysts, and emphasizes the practicality and importance of the CoSAs‐NCs/CN/TiO2 catalyst in effectively and long‐term remediation of water pollutants. [ABSTRACT FROM AUTHOR]

The development of efficient rare earth single‐atom (SA) catalysts for the oxygen reduction reaction (ORR) is essential yet challenging for high‐performance aluminum‐air batteries (AABs). This study introduces a concept‐to‐proof strategy for synthesizing a hollow carbon‐supported gadolinium (Gd) SA catalyst using low‐coordination and second‐coordination sphere engineering. In this design, Gd atoms are coordinated to three nitrogen (N) atoms in N‐doped carbon and surrounded by six phosphorus (P) atoms, forming Gd‐N3‐P6 sites. These catalysts demonstrated exceptional ORR performance, achieving a half‐wave potential of 0.895 V and superior durability compared to the commercial Pt/C benchmark. When integrated into AABs, they delivered impressive performance, with a peak power density of 257 mW/cm2 and an energy density of 2916 Wh/kg, alongside enhanced cycling stability. In situ characterization and theoretical calculations revealed that the strategic placement of P atoms in the second coordination sphere significantly enhanced the valence state of the Gd site. This enhancement improved the adsorption capacity for O2 and H2O while facilitating the rapid desorption of *OH intermediates during the ORR. This study offers valuable insights into the development of cost‐effective ORR catalysts, emphasizing the significance of modulating the local coordination environment of metal SA sites. [ABSTRACT FROM AUTHOR]

Integrating active sites for oxygen reduction and evolution reactions (ORR and OER) is pivotal for advancing bifunctional oxygen electrodes. Addressing the geometric/electronic properties of these sites is essential to disrupt the linear scaling relationship between the adsorption and desorption of complex intermediates. Herein, a proof‐of‐concept is presented for constructing asymmetric trinuclear sites employing both composition‐ and size‐based asymmetric coupling strategies. These sites comprise ORR‐active Fe single atom (FeSA), OER‐active atomically clustered Fe species (FeAC), and NiSA sites as modulators. This FeAC‐SA‐NiSA@N‐doped carbon exhibits excellent bifunctional catalytic activities, with a narrow potential gap of 0.661 V between an ORR half‐wave potential of 0.931 V and an OER potential of 1.592 V at 10 mA cm−2. The Zn‐air battery employing this material achieves a peak power density of 293 mW cm−2, a specific capacity of 748 mAh gZn−1, and remarkable stability. Experimental findings and theoretical simulations reveal that NiSA sites induced strong electronic coupling among the trinuclear centers, facilitating charge redistribution and optimizing the adsorption and desorption barriers for intermediates. This enhances the rapid release of *OH during ORR and the efficient transformation from *O to *OOH during OER. This study presents a novel strategy for developing robust bifunctional oxygen electrodes. [ABSTRACT FROM AUTHOR]