Specific Area Research Articles

Nitrogen-doped porous carbon nanosheets derived from furfural residue as an oxygen reduction catalyst

The complex pore structure of porous carbon plays a pivotal role in determining the catalytic activity of catalysts involved in the oxygen reduction reaction (ORR), and template methods have emerged as the gold standard in the fabrication of porous carbon. This study describes the preparation of a series of carbon materials that use furfural residue and urea as carbon and nitrogen sources, respectively, in conjunction with KOH as an activating agent through a template method. The prepared catalysts have a large specific surface area and an abundance of micro/mesoporous structures, both of which facilitate ion transport and promote active site exposure. Notably, the sample with a carbon-to-nitrogen mass ratio of 1:4 (FR/C-4) exhibits an exceptionally high specific surface area (2190 m2 g−1) along with an impressive array of pore structures. Compared with commercial Pt/C, FR/C-4 demonstrates superior ORR catalytic activity with a half-wave potential (E1/2) of 0.88 V. Furthermore, FR/C-4 demonstrates remarkable stability and methanol tolerance in alkaline electrolytes, indicating its potential for a wide range of applications, such as fuel cells and metalair batteries.

Nitrogen-doped carbon nanosheet confined PtNi alloy for efficient acidic electrocatalytic hydrogen evolution reaction

Low intrinsic electrocatalytic activity and inferior conductivity limit the application of Ni/NC in acidic electrocatalytic hydrogen evolution reaction (HER). Herein, we prepared nitrogen-doped carbon nanosheet confined PtNi alloy electrocatalysts (PtNi/NC-10) using PtCl62− electrostatic adsorption coupling melamine pyrolysis nitriding strategy. PtNi alloying was confirmed by the crystallinity decrease and lattice expansion of Ni/NC. The alloying and confinement effect of Metal-Organic Frameworks (MOFs) suppresses the oxidation and agglomeration of metal nanoparticles during pyrolysis, thus significantly reducing particle size, increasing specific surface area, and promoting the exposure of active sites. The strong electronic interaction between Pt and Ni optimizeds the surface charge distribution, enhancing the adsorption of H species on electron-rich Pt sites, thereby improving reaction kinetics. In addition, PtNi alloying improves the conductivity of the material, accelerating charge transfer and proton transport. Consequently, the prepared PtNi/NC-10 exhibits superior HER performance than Ni/NC in 0.5 M H2SO4 solution, even comparable to commercial 20 wt% Pt/C, with the overpotentials of 35 mV at 0.01 A cm−2. Furthermore, the electrocatalysts assembled PtNi/NC-10-CP‖RuO2-TFF proton exchange membrane (PEM) electrolyzer only requires 2.32 V cell voltage to achieve 1 A cm−2, presenting practical application prospects. Our work provides a novel idea for designing efficient and stable MOFs confined to alloy-based HER electrocatalysts.

CNTs@fabric/Ni@PU piezoresistive sensor with enhanced interfacial contact resistance variation for motion detection and deep-learning-assisted recognition

Abstract Flexible piezoresistive sensors based on the mechanism of interfacial contact resistance change are receiving increasing attention in the fields of human-computer interaction, health monitoring, and behavior tracking. However, the high cost and complex manufacturing process limit the wide application and development of these flexible piezoresistive sensors. Here, a novel carbon nanotubes@fabric (CNTs@fabric)/Ni@polyurethane (Ni@PU) piezoresistive sensor (CNPS) with low-cost, simple-preparation and high-sensitivity was proposed. The effective contact area is obtained by synergizing the woven micro-convex structure of the fabric, the large specific surface area of the CNTs and the porous three dimensional electrodes. Within the small pressure (0–9.52 kPa) effect, the area of connection with the electrodes to the active layer plays a dominant role, resulting in a sensitivity of up to 6.39 kPa−1 for CNPS. In the high pressure region (9.52–44.92 kPa), where internal mechanism of change in the sensitive material dominants, the CNPS has a response time of 85 ms at a constant pressure of 28.31 kPa. Considering the excellent output electrical performances, a variety of body movements could be detected by fixing the CNPS to different joints. Significantly, the designed intelligent object recognition system implemented by the combination of matrix stress detection module and residual neural network (ResNet) algorithm has a recognition accuracy of 99.26%. Enhancing the interfacial contact resistance change mechanism using a simple fabrication process offers a promising strategy for the rapid development of flexible piezoresistive sensors.

A nickel porphyrin-based covalent organic framework modified electrode for the electrochemical detection of acetaminophen.

Covalent organic frameworks (COFs) can be rationally designed with functional organic ligands to improve the electrochemical responsiveness of the electrode toward certain medicinal compounds. In this study, we synthesized a COF-Ni electrocatalyst material, which is formed by covalent coupling of electron-rich 2,3,6,7-tetrakis (4-formylphenyl) tetrakis (4-imidazolyl) (TTF-4CHO) and hole-rich 5,10,15,20-tetrakis (4-aminophenyl) porphyrin nickel(II) (TAPP-Ni). The reasonable electron transfer path design, the large specific surface area of the COF and the physical properties of ordered nanopores, as well as the Ni-N4 bond as a highly active catalytic center, allow the COF-Ni material modified electrode to exhibit excellent sensing performance for acetaminophen (ACOP). The detection limit for ACOP is as low as 47.6 nM, with a linear range of 1-1500 μM, which is better than for most of the reported sensors. With superior interference resistance and good stability performance, COF-Ni is a highly suited electrode modification material for real-world sample detection, which provided a new perspective for application of COF materials in drug analysis.

A Bacterial Capturing, Neural Network-Like Carbon Nanotubes/Prussian Blue/Puerarin Nanocomposite for Microwave Treatment of Staphylococcus Aureus-Infected Osteomyelitis.

Staphylococcus aureus (S. aureus)-infected osteomyelitis is a deep tissue infection that cannot be effectively treated with antibiotics. Microwave (MW) thermal therapy (MTT) and MW dynamic therapy (MDT) based on MW-responsive materials are promising for the therapy of bacteria-infected osteomyelitis occurring in deep tissues that cannot be effectively treated with antibiotics. In this work, the MW-responsive system of carbon nanotubes (CNTs)/Prussian blue (PB)/puerarin (Pue) with stable network-like structures is constructed. The PB is grown in situ on the CNTs, and its introduction not only reduces the aggregation of the network-like structures of the CNTs, but the large specific surface area and mesoporous structure can also provide many active sites for the adsorption of oxygen and polar molecules. Pue is a natural anti-inflammatory material that reduces inflammation at the infection site. The composite of the CNTs and PB avoids the skin effect and thus can improve dielectric and reflection losses. The MW thermal response of CNTs/PB/Pue is mainly due to the occurrence of reflection loss, dielectric loss, multiple reflections and scattering, interface polarization, and dipole polarization. In addition, under MW irradiation, the CNTs/PB/Pue can produce reactive oxygen species (ROS), such as singlet oxygen (1O2), hydroxyl radical (·OH).

The Effects of Support Specific Surface Area and Active Metal on the Performance of Biphenyl Selective Hydrogenation to Cyclohexylbenzene

The Effects of Support Specific Surface Area and Active Metal on the Performance of Biphenyl Selective Hydrogenation to Cyclohexylbenzene

Surface acoustic wave platform integrated with ultraviolet activated rGO-SnS2 nanocomposites to achieve ppb-level dimethyl methylphosphonate detection at room-temperature

Dimethyl methylphosphonate (DMMP) is commonly used as an alternative for demonstrating to detect sarin, which is one of the most toxic but odorless chemical nerve agents. Among various types of DMMP sensors, those utilizing surface acoustic wave (SAW) technology provide notable advantages such as wireless/passive monitoring, digital output, and a compact, portable design. However, key challenges for SAW-based DMMP sensors operated at room temperature lies in simultaneous enhancement of sensitivities and reduction of detection limits. In this study, we developed a binary material strategy by combining reduced graphene oxide (rGO) and tin disulfide (SnS2) with (100)-facets orientation as sensing layers of SAW device for DMMP detection utilized at room temperature. Ultraviolet (UV) light was applied to activate the sensitive film and reduce the sensor's response time. The developed SAW DMMP sensor demonstrated a superior sensitivity (−1298.82 Hz/ppm), a low detection limit of 50 ppb, and a hysteresis below 1.5%, along with fast response/recovery time (39.2 s/28.4 s), excellent selectivity, long-term stability and repeatability. The formation of shrub-like rGO-SnS2 heterojunctions with abundant surface defects and large specific surface areas, high-energy (100) crystalline surfaces of SnS2, and photogenerated carriers generated by UV irradiation were pinpointed as the crucial sensing mechanisms. These factors collectively enhanced adsorption and reaction dynamics of DMMP molecules.

Exfoliated Porous Carbon Nitride by Simultaneous Oxidation-Corrosion for Photocatalytic H2O2 Production and Organic Degradation.

Graphitic carbon nitride (g-C3N4) is a fascinating material with potential applications in photocatalysis due to its good chemical stability, high thermal stability, and relative ease of synthesis. In this work, ultrathin g-C3N4 is constructed using a hybridized method, which combines the advantages of thermal and liquid-phase stripping methods. This sample can improve performance in degrading organic pollutants several times, and the highest enhancement efficiency occurs in an alkaline environment. In addition, photocatalytic production of hydrogen peroxide can be increased to 2.6 times that of the bulk sample. These improved properties are due to the increase in specific surface area, the generation of free radicals, and adsorption capacity. This work presents a one-step exfoliation method for bulk g-C3N4 for more surface-active sites and strong redox capacity.

Acid-treated waste sisal fiber derived activated carbon as efficient electrode material for solid-state supercapacitor

Activated Carbon (AC), obtained from biomass is highly adaptable and valued for its versatile benefits including high surface area, conductivity, chemical inertness, etc. in various applications. It is also used as an electrode in supercapacitors for applications requiring a high-power supply. Sisal fiber, derived from the Agave sisalana plant, has several advantages, including its fibrous and porous framework, that make it suitable for conversion into activated carbon for energy storage applications in the context of sustainability and reduced environmental impact. In this study, we have prepared H2SO4 treated KOH activated carbon from residual Sisal fiber (SFH2AC) which is then utilized as an electrode material for supercapacitors. SFH2AC exhibits hierarchical and structure-based porosity with a large specific surface area (SA) of 1185 m2/g and shows the maximum specific capacitance (Cs) of 340 F/g @ 0.5 A/g in 6 M KOH electrolyte. In KOH electrolyte, strong cycling retention (during the length of 9000 GCD cycles) is attained as; 98 % up to the first 3000 cycles at 10 A/g, 93 % up to next 3000 cycles at 20 A/g, and 90 % up to the last 3000 cycles at 30 A/g. Furthermore, the SFH2AC//SFH2AC(Gel) device was built by using SFH2AC as electrodes with PVA/KOH gel as an electrolyte in order to assess the supercapacitor performance in real time. The device has a specific power density of 7500 W/kg and a maximum energy density of 12 W h/kg. The device reveals an exceptional 97 % cycling stability, maintaining up to 9000 repeated GCD cycles at an increased current density (CD) of 30 A/g.

Covalent Lysozyme Immobilization on Enzymatic Cellulose Nanocrystals.

Nanostructured materials represent promising substrates for biocatalyst immobilization and activation. Cellulose nanocrystals (CNCs), accessible from waste and/or renewable sources, are sustainable and biodegradable, show high specific surface area for anchoring a high number of enzymatic units, and high thermal and mechanical stability. In this work, we present a holistic enzyme-based approach to functional antibacterial materials by bioconjugation between the lysozyme from chicken egg white and enzymatic cellulose nanocrystals. The neutral CNCs were prepared by endoglucanase hydrolysis from Avicel. We explore the covalent immobilization of lysozyme on enzymatic CNCs and on their TEMPO oxidized derivatives (TO-CNCs), comparing immobilization yields, material properties, and enzymatic activities. The materials were characterized by X-ray diffractometry (XRD), attenuated total reflectance Fourier Transform infrared spectroscopy (ATR-FTIR), bicinchoninic acid (BCA) assay, field-emission scanning electron microscopy (FE-SEM) and dynamic light scattering (DLS). We demonstrate the higher overall efficiency of the immobilization process carried out on TO-CNCs, based on the success of covalent bonding and on the stability of the isolated bioconjugates.

C3N4/Se-CNTs as Advanced Metal-Free Catalysts for the Photoassisted Electrocatalytic Oxygen Evolution Reaction.

Photoassisted electrocatalysis is a frontier direction of electrocatalysis for promoting energy conversion. In this work, a metal-free C3N4/Se-CNTs is reported as a novel catalyst for photoassisted electrocatalytic oxygen evolution reaction (OER). C3N4 has an appropriate bandgap, high specific surface area, and long-term stability. CNTs can modulate the electronic environment of C3N4 by strong π-π interaction and greatly enhance the separation efficiency of photogenerated carriers. The distributed Se nanoparticles in CNTs can further increase the charge transfer ability. As a metal-free catalyst, the C3N4/Se-CNTs exhibits an overpotential of 231 mV at a current density of 10 mA cm-2 and a small Tafel slope of 52 mV dec-1 under illumination, which ranks among the best catalysts for photoassisted OER performance, surpassing most noble and transition metal-based catalysts. The result demonstrates the great potential of C3N4-based catalysts in the photoassisted OER process and provides a new perspective to explore the excellent metal-free OER catalysts.

Construction of a Defective Chiral Covalent Organic Framework for Fluorescence Recognition of Amino Acids.

The design and synthesis of chiral covalent organic frameworks (COFs) with controlled defect sites are highly desirable but still remain largely unexplored. Herein, we report the synthesis of a defective chiral HD-TAPB-DMTP COF by modifying the chiral monomer helicid (HD) into the framework of an achiral imine-linked TAPB-DMTP COF using a chiral monomer exchange strategy. Upon the introduction of the chiral HD unit, the obtained defective chiral HD-TAPB-DMTP COF not only displays excellent crystallinity, large specific surface area (up to 2338 m2/g) and rich accessible chiral functional sites but also exhibits fluorescence emission, rendering it a good candidate for discrimination of amino acids. Notably, the resultant defective chiral HD-TAPB-DMTP COF can be used as a fluorescent sensor for enantioselective recognition of both tyrosine and phenylalanine enantiomers in water, showing enhanced fluorescent responses for the L conformations over those of the D conformations with the enantioselectivity factors being 1.84 and 2.02, respectively. Moreover, molecular docking simulations uncover that stronger binding affinities between chiral HD-TAPB-DMTP COF and L-tyrosine/L-phenylalanine in comparison to those with D-tyrosine/D-phenylalanine play important roles in enantioselective determination. This work provides new insights into the design and construction of highly porous defective chiral COFs for enantioselective fluorescence recognition of amino acids.

Exploring the potential of two-dimensional MB4 (M=Cr, Mo, and W) monolayer as a high-capacity negative electrode material for Al-ion batteries

Rechargeable metal-ion batteries can employ two-dimensional transition metal tetraboride monolayers because of their numerous accommodating sites, high specific surface area, and layered structure. Li-ion batteries (LIBs) can be efficiently replaced by aluminum ion batteries (AIBs) because aluminum is a cheap and abundant resource. In this work, the density functional theory approach has been used for Al-ion batteries to predict MB4(M= Cr, Mo, W) monolayers performance as anode material. We analyze these monolayers' structures, which are mechanically, thermally, and dynamically stable. Utilizing the energy-efficient adsorption of six Al-atom layers and their lightweight properties, with large storage capacities of 5066 mA h g−1, 3466 mA h g−1, and 2124 mA h g−1, with relatively low average open circuit voltages of 0.18 V, 0.15 V, and 0.11 V for CrB4, MoB4, and WB4, respectively, these monolayers show significant superiority over other 2D anode materials. Likewise, MB4 monolayer showed faster Al ion mobility as seen by the low activation barriers of 0.95 eV, 0.83 eV, and 0.49 eV for CrB4, MoB4, and WB4, respectively. Additionally, even after the full content of Al ions was adsorbed, the metallic characteristics of the materials were mostly retained. These traits suggest that monolayer CrB4, MoB4, and WB4 are promising anode materials for AIBs, with impressive rate capacities.

Sorption/desorption of phenanthrene and ofloxacin by microbial-derived organic matter-mineral composites

IntroductionSoil organic matter plays an important role in the long-term “locking” of organic contaminants in soil environment. Recently, microbial-derived organic matter have been recognized as essential components of stabilized soil carbon pools. However, the contribution of microbial-derived organic matter to sorption of organic contaminants remains unclear.MethodsHere, we obtained microbial-derived organic matter-mineral composites by inoculating model soil (a mixture of hematite and quartz sand (FQ) or montmorillonite and quartz sand (MQ)) with natural soil microorganisms and different substrate-carbon (glycine (G), glucose (P), or 2, 6-Dimethoxyphenol (B)), which were named GF, PF, BF, GM, BM, and PM, respectively. Batch sorption/desorption experiments were conducted for phenanthrene (PHE) and ofloxacin (OFL) on the composites.Results and DiscussionThe composites cultured with 2,6-dimethoxyphenol had the highest carbon content (0.98% on FQ and 2.11% on MQ) of the three carbon substrates. The carbon content of the composites incubated with MQ (0.64%–2.11%) was higher than that with FQ (0.24%–0.98%), indicating that montmorillonite facilitated the accumulation of microbial-derived organic matter owing to its large specific surface area. The sorption of PHE by microbial-derived organic matter was mainly dominated by hydrophobic partitioning and π-π conjugation, whereas the sorption of OFL was mainly dominated by hydrophobic hydrogen bonding and π-π conjugation. The sorption of OFL onto the composites was more stable than that of PHE. Microbial-derived organic matter -mineral composites can reduce the risk of organic contaminant migration in soil, particularly ionic organic contaminants.

Engineering of in-plane SnS2–SnO2 nanosheets heterostructures for enhanced H2S sensing

In-plane heterostructures has attracted considerable interest due to exceptional electron transport properties, high specific surface area, and abundant active sites. However, synthesis of in-plane SnS2–SnO2 heterostructures are rarely reported, and the deep investigation of the fine structure on reactivity is of great significance. Here, we propose partial in-situ oxidation strategy to construct the in-plane SnS2–SnO2 heterostructures and the surface properties, the ratio of two components can be finely tuned by precisely adjusting the treatment temperature. In particular, the SnS2–SnO2 heterostructures formed after annealing of SnS2 nanosheets at 350 °C exhibits a unique electronic structure and surface properties due to rich grain boundaries, which exhibits excellent gas sensing performance to H2S (Ra/Rg = 169.81 for 5 ppm H2S at 160 °C, fast response and recovery dynamic (41/101 s), excellent reliability (σ = 0.01) and sensing stability (φ = 0.11 %)). Notably, the in-plane heterostructures endow the material with abundant grain boundaries and effectively regulates the electronic structure of the Sn p-orbital, which facilitate the formation of active oxygen species (O−(ad)), thus contributing to the sensing performance. Our work provides a promising platform to design in-plane heterostructures for various advanced applications.

Interface-assisted synthesized covalent organic framework film for efficient extraction of microcystins in aquatic organisms

Covalent organic framework (COF) film-based solid-phase extraction (F-SPE) has garnered great attention in sample pretreatment. However, harsh synthesis conditions of COF films have severely hindered their potential applications. In this study, a kind of COF (TPB-DMTP) films were fabricated via a liquid-liquid interfacial synthesis method at a mild condition. The obtained films exhibited excellent extraction performance towards microcystins (MCs, an algal toxin) due to their porous structure, high specific surface area and abundant accessible adsorption sites. Coupled TPB-DMTP films-based F-SPE with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a sensitive and environment-friendly analytical method was established for MCs detection. Under the optimal conditions, this method possessed wide linear ranges (2.0–800.0 pg mL−1) with good linearity (R ≥ 0.9991), low limits of detection (0.8–3.0 pg mL−1) and satisfactory precision (RSDs ≤7.1 %), which then successfully applied for MCs detection in actual aquatic organism samples. Trace amounts of MC-RR (42.4 pg mL−1) and MC-YR (14.6 pg mL−1) were detected in the mussels. The results demonstrate the excellent application potential of COF films in sample pretreatment.

[formula omitted] Affects the crystalline calcium silicate hydrate minerals synthesized by fly ash-based silicon extraction solution and lime milk

When extracting amorphous silicon from fly ash using a strong alkaline solution, other elements such as Al also enter the silicon extraction solution in the form of AlOH4−. To systematically investigate the impact of AlOH4− on the synthesis of typical calcium silicate hydrate crystals in a silicon extraction solution, a specific amount of AlOH4− was added to the silicon extraction solution, and calcium silicate was hydrothermally synthesized at 90℃ and 230℃. Scanning electron microscopy (SEM) and Brunner−Emmet−Teller (BET) analysis revealed that with the increasing in AlOH4− content, microporous calcium silicate gradually loses its microporous morphology. While the specific surface area shows no significant change, the median pore diameter first increases from 1.47 nm to 1.58 nm and then decreases to 1.55 nm. The xonotlite fibers underwent a gradual refinement, diminishing from 0.28 to 0.15 µm. Simultaneously, the specific surface area increases from 28.87 to 56.8 m2/g. At an AlOH4− concentration of 3 mol/L, the microscopic morphology transforms into a sheet-like structure. X-ray diffraction (XRD) analysis reveals that AlOH4− promotes the formation of tobermorite while inhibiting the further development of calcium silicate. Additionally, Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance indicate that Al can replace Si in the calcium silicate hydrate system, primarily substituting positions the Q2 and Q3 sites. Qualitatively, it is suggested that with the increasing incorporation of Al, the polymerization degree of the silicon-oxygen tetrahedra decreases. According to experimental results, the concentration of AlOH4− should be below 0.05 mol/L when synthesizing microporous calcium silicate hydrate and less than 0.2 mol/L when synthesizing fibrous xonotlite-type calcium silicate hydrate.

NiMOF-Derived MoSe2/NiSe Hollow Nanoflower Structures as Electrocatalysts for Hydrogen Evolution Reaction in Alkaline Medium.

Metal-organic frameworks (MOFs) are crystalline porous materials for storage and energy conversion applications with three-dimensional pore structure, high porosity, and specific surface area, which are widely utilized in electrocatalysis. Herein, MoSe2/NiSe composites were synthesized by selenization reaction using NiMOF as the precursor. The composites were hollow nanoflower structures with a synergistic effect between MoSe2 and NiSe to promote rapid electron transfer, which exhibited good hydrogen evolution reaction performance in an alkaline medium. At a current density of 10 mA/cm2, the HER overpotential reaches 80 mV, the Tafel slope is 33.86 mV/dec, and the material has good stability, with polarization curves remaining essentially unchanged after 3000 cycles. These results indicate that the method has a promising application in the preparation of efficient and sustainable catalysts for hydrogen production in alkaline medium.

Olfactory Visualization Sensing Array Made with CelluMOFs to Predict Fruit Ripeness Using Deep Learning.

Developing a colorimetry-based artificial scent screening system (i.e., an olfactory visual sensing system) with high sensitivity and accurate pattern recognition for detecting fruit ripeness remains challenging. In this work, we construct a flexible dye/CelluMOFs-based sensor array with improved sensitivity for on-site detection of characteristic gases of fruits and integrate a densely connected convolutional network (DenseNet) into the sensor array, enabling it to recognize unique scent fingerprints and categorize the ripeness of fruits. In the system, CelluMOFs are synthesized through in situ growth of γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) on flexible fiber filter paper to fabricate a uniform, flexible and porous dye/CelluMOFs sensitive membrane. Compared to the pristine filter paper, the CelluMOFs exhibit increased porosity with a 62 times higher specific surface area and a 3-fold increase in dye loading capacity after 12 h of adsorption. The prepared dye/CelluMOFs sensing film shows outstanding mechanical and detection stability with negligible deviation after 100 cycles of rubbing. The colorimetric visualization arrays with multiple colorimetric dye/CelluMOFs chips, enable the sensitive recognition and detection of nine kinds of characteristic fruit odors and achieve a high response at 8-1500 ppm of trans-2-hexenal, showcasing remarkably low gas detection thresholds. On the basis of the ppm-level limit of detection with high sensitivity, the fabricated colorimetric sensor arrays are typically used for in situ assessment of fruit ripeness by integrating DenseNet. This approach achieves a satisfactory classification accuracy of 99.09% on the validation set, enabling high-precision prediction of fruit ripeness levels.

Research over the effect of activated carbon treated with calcium nitrate solution on the catalytic ability in the reduction of Co(III)Triethylenetetramine

AbstractActivated carbon can be used as a catalyst for the reduction of Co(III)TETA to Co(II)TETA so as to maintain the ability of removing NO from gas stream with Co(II)TETA solution. Calcium nitrate has been utilized to treat activated carbon to improve its catalytic ability in the regeneration of Co(II)TETA. The biggest Co(III)TETA conversion is gained by the carbon being soaked in 0.3 mol/L calcium nitrate solution at 65°C for 12 h with a solid/liquid ratio of 1 g/50 mL followed being carbonized at 400°C for 2 h in nitrogen. The characterization with Fourier transform infrared spectroscopy, XPS, BET (Brunauer‐Emmett‐Teller) and Boehm titration indicates that the modification with calcium nitrate increases the specific surface area and acidic groups on activated carbon. The continuous experiments reveal that the NO removal efficiency obtained by the modified carbon is over 12% up to that by the original one.