Catalytic Activity Research Articles

Fe3O4@gC3N4@Thiamine: a novel heterogeneous catalyst for the synthesis of heterocyclic compounds and microextraction of tebuconazole in food samples

Graphite carbon nitride (g-C3N4) is a two-dimensional nano-sheet with electronic properties, which shows unique characteristics with high chemical and thermal stability in its structure. The functionalization of these compounds through covalent bonding is an important step towards significantly improving their properties and capabilities. To achieve this goal, a novel strategy for the covalent functionalization of Fe3O4@g-C3N4 with thiamine hydrochloride (vitamin B1) via cyanuric chloride (TCT), which is a divalent covalent linker, was presented. The efficiency of Fe3O4@gC3N4@Thiamine as a heterogeneous organic catalyst in the synthesis of spirooxindole-pyran derivatives and 2-amino-4H-pyran under solvent-free conditions was evaluated and the yields of high-purity products were presented. In addition, easy recycling and reuse for seven consecutive cycles without significant reduction in catalytic activity are other features of this catalyst. Moreover, the performance of the prepared sorbent in the microextraction technique (herein, magnetic solid phase extraction) was studied. The tebuconazole was selected as the target analyte. The target analyte was extracted and determined by HPLC–UV. Under the optimum condition, the linear range of the method (LDR) was estimated in the range of 0.2–100 μg L−1 (the coefficient of determination of 0.9962 for tebuconazole). The detection limit (LOD) of the method for tebuconazole was calculated to be 0.05 µg L−1. The limit of quantification (LOQ) of the method was also estimated to be 0.16 µg L−1. In order to check the precision of the proposed method, the intra-day and inter-day relative standard deviations (RSD%) were calculated, which were in the range of 1.5- 2.8%. The method was used for the successful extraction and determination of tebuconazole in tomato, cucumber, and carrot samples.

Biosynthesis and Characterization of Silver Nanoparticles Mediated by Seed Extract of Macassar Ebony with Catalytic and Antimicrobial Activity

Biosynthesis and Characterization of Silver Nanoparticles Mediated by Seed Extract of Macassar Ebony with Catalytic and Antimicrobial Activity

Eco-friendly synthesis of reduced graphene oxide/palladium composite and its catalytic, antibacterial and antifungal activities for bone regeneration and fracture treatment

Nanocomposites based on inorganic/graphene nanoparticles have gained remarkable interest as a novel class of hybrid materials. Scientific community attention towards these substances has been increasing, because of their peculiar characteristics in combining anticipated features of building constructs for specified applications. Graphene oxide (GO) and metal nanoparticles (MNPs) are using separately in different applications due to their specific limitations. Researchers continue to explore ways to overcome these challenges and create functional nanomaterials for various fields by combining unique advantages of GO and MNPs. Here, we used a facile one-step method for the synthesis of reduced graphene oxide–palladium composite (RGO/Pd). Environmental-friendly biofabricated palladium nanoparticles adhered to Polyscias scutellaria (PS) leaf extract mediated RGO/Pd have been presented in the current investigation. The biofabricated nanohybrid (RGO/Pd) was analysed utilizing several microscopic and spectroscopic techniques. Further, we have also examined the catalytic function for the reduction of 2-nitroaniline (2-NA) in detail. Primarily, we observed that the synthesized nanocomposite can catalyse simultaneous reduction of 2-NA. Furthermore, an added advantage of the as prepared RGO/Pd nanocomposite is its antimicrobial and antifungal ability. Further, we exhibited that the mesenchymal stem cells of adult goat were viable in the presence of RGO/Pd of 0.1 mg/mL concentration and their properties of stem cells were retained. The outcomes displayed that the nanocomposites exhibited outstanding functioning in the killing of dangerous microbial and fungal pathogens. All these results strengthen the RGO/Pd composite applicability in future for potential therapy in bone tissue engineering applications.

Facile and innovation synthesis of Zn-Mn-Co-LDH/polypyrrole and its application in investigating ethanol oxidation in an alkaline medium

Overvoltage and low current are observed for ethanol electrooxidation on the surface of many unmodified electrodes. Therefore, it is desirable to use a suitable catalyst for ethanol electrooxidation to increase the current. This research introduces a new sensor to catalyze ethanol oxidation in an alkaline environment. This new Zn-Mn-Co LDH/PolyPyrrole/GCE nanocomposite sensor exhibits high catalytic activity for ethanol electrooxidation. It changes the oxidation potential of ethanol to a less positive potential. To identify this proposed sensor, X-ray diffraction (XRD), Brauner Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, field emission scanning electron microscopy (FESEM), thermal analysis (TGA), high-resolution transmission electron microscopy (HR-TEM) and cyclic voltammetry techniques were used. Ethanol electrooxidation was investigated by cyclic voltammetry technique. The effects of scan rate and ethanol concentration on the ethanol oxidation peak have been investigated. The proposed sensor showed long-term stability. This prepared nanocomposite can be used as an anode catalyst for ethanol fuel cells.

Structural insights into polyethylene terephthalate (PET)-degrading archaeal lipase enzyme: An insilico approach

Biodegradation of plastic is the most eco-friendly degradation process conferred by various microbial enzymes, especially the lipase enzymes. The lipase enzymes depict a broad substrate range, high regio/stereoselectivity, and stability in organic solvents. However, enhancing the catalytic activity of lipases for industrial production remains a challenge, predominantly due to the need for their extensive mechanistic characterization. Here, we employed a multidisciplinary approach to illustrate the comprehensive physiochemical and mechanical properties of 102 lipase sequences from six different groups of plastic-degrading microorganisms. Molecular docking-based evaluation of the binding efficiencies of selected lipases with the most common plastic polymers- polyurethane (PUR) and polyethylene terephthalate (PET), revealed that the archaeal lipase had the lowest binding energy of −7.1 kcal/mol with PET. Remarkably, the molecular dynamic simulation studies (up to 100 ns) and very low RMSD (0.3 nm) and RMSF (0.25 nm) values further ascertained the stability of archaeal lipase after binding with PET polymer. Further, a 2.19 nm radius of gyration (Rg) within 100 ns simulation time, binding free energy ΔGTOTAL with −24.36 kcal/mol and entropy factor -TΔS 7.65 kcal/mol also indicated strong binding of archaeal lipase with PET polymer. The mechanistic exploration of archaeal lipase yielded valuable insights into its effective binding with PET polymer, paving the way for future lipase enzyme engineering and harnessing its industrial potential for plastic biodegradation.

Facile boosting catalytic thermal decomposition of ammonium perchlorate from 3D porous nano Co3O4@ZnO composites

The design of efficient catalysts for the pyrolysis of ammonium perchlorate (AP) is important for the performance of composite solid propellants. Co3O4@ZnO heterojunction composites were fabricated by hydrothermal and calcination treatments and used to promote the thermal decomposition of AP. The influences of the Co/Zn molar ratio on the catalytic performance and the content of decomposition products of AP were investigated by various techniques such as TEM, XPS, BET, EIS, and TG-IR. The results revealed that the Co/Zn = 3 sample exhibited excellent performance with the high-temperature decomposition (HTD) temperature of AP reduced from 410°C to 295 °C and the apparent activation energy decreased to 98.7 kJ/mol in the case of 2 wt% addition, attributed to the construction of a heterojunction with abundant active sites enhancing the charge transfer capability between the Co3O4 and ZnO. The decomposition pathway of AP is influenced by the catalyst components, and the Co/Zn = 3 nanostructures demonstrated outstanding catalytic performance by accelerating the decomposition of HClO4 and the conversion of NH3, and promoting the production of N2O, NO, and NO2. This work provides a feasible strategy for the development of Co3O4@ZnO catalysts with excellent catalytic activity towards AP.

Sustainable Synthesis of D‐Glucose Based IL: A Renewable Organo Catalyst for the Efficient Synthesis of Dihydropyrano Coumarins

A convenient, direct, one‐pot highly efficient microwave‐assisted synthesis of biomass‐derived D‐glucose‐based hydroxide ionic liquid via a simple three‐step approach has been described. The key features of the method include rapidness, eco‐friendliness, and excellent yields. To the best of our knowledge, this is the first methodology for synthesizing D‐Glucose‐based sugar ionic liquid (GSIL) under microwave irradiation. The developed catalyst allowed us to synthesize diverse dihydropyrano[3,2‐c]‐chromenes upto 95% yield in 30‐90 min stirring at 80 ̊C under mild conditions. The scope of the study was investigated using 30 instances. Developed GSILs exhibited excellent catalytic activity as well as good recyclability. Overall, the catalyst showed excellent value in green chemistry parameters such as atom economy (95%), E‐factor (0.05), carbon efficiency (100%), process mass intensity (1.62), and reaction mass efficiency (0.860).

Switchable transformation of biomass-derived furfural to furfuryl alcohol and isopropyl furfuryl ether over a zirconium-based bifunctional catalyst

Selectively converting biomass-derived furfural (FF) to furfuryl alcohol (FFA) and isopropyl furfuryl ether (IPFE) via the same catalytic system is an important strategy for the production of high-value chemicals and fuels. However, this strategy still faces a great challenge because the formation of FFA and IPFE requires different catalyst types and reaction conditions. Hence, developing a compatible catalytic system is extremely necessary. In this work, we designed a high-efficiency zirconium-based bifunctional catalyst (Zr-HC-SO3H), simultaneously containing Lewis acid-base sites (Zr4+–O2−) and Brønsted acid sites (–SO3H), which were mainly responsible for the Meerwein-Ponndorf-Verley reduction reaction of FF and further etherification reaction of FFA, respectively. By controlling reaction conditions, the action orders and catalytic activities of Zr4+–O2− and –SO3H could be accurately regulated. Thus, Zr-HC-SO3H showed excellent catalytic performance for the switchable transformation of FF, leading to 98.9 % FFA yield at 120 °C for 4 h and 95.1 % IPFE yield at 170 °C for 12 h in isopropanol (iPrOH). Additionally, the analysis results of reaction pathways indicated that the etherification of FFA was much more difficult than the reduction of FF over Zr-HC-SO3H in iPrOH, so IPFE was only formed under the harsher reaction conditions. More significantly, Zr-HC-SO3H also catalyzed the switchable transformation of many other carbonyl compounds and demonstrated satisfactory catalytic universality in iPrOH. In conclusion, this work offered some momentous clues for the development of multipurpose catalytic systems and the controllable synthesis of valuable products in the biorefinery process.

Enhancement of peroxymonosulfate activation through regulating electronic structure of cobalt phthalocyanine by g-C3N4 for rhodamine B degradation

The catalytic performance of cobalt-based catalysts in Fenton-like reactions is significantly influenced by the electron density of Co centers. However, precise control of the electronic structure to enhance the degradation activity remains a challenge. This paper demonstrates a method to enhance the catalytic activity of cobalt phthalocyanine (CoPc) by modulating its electronic structure via integrating with graphitic carbon nitride (g-C3N4). The electron redistribution between g-C3N4 and CoPc was observed, resulting in electron-rich Co centers. Consequently, the CoPc/g-C3N4 composites exhibit significantly enhanced peroxymonosulfate (PMS) activation capability compared to CoPc and their physical mixtures. The improved catalytic performance is due to the electron-rich Co centers, better dispersion of CoPc, and enhanced hydrophilicity. This study proposes a novel strategy for the design of efficient PMS activation catalysts.

Neutrophil membrane-based biomimetic metal-polyphenol self-assembled nanozyme for the targeting treatment of early brain injury following subarachnoid hemorrhage

Early brain injury (EBI) refers to the immediate injury and neuroinflammation in the brain after subarachnoid hemorrhage (SAH). The current drugs used to treat SAH are inadequate due to their disappointing ability to penetrate the blood–brain barrier (BBB) and their limited anti-inflammatory effects, leading to unsatisfactory therapeutic outcomes for EBI. Herein, we developed a biomimetic nanozyme (Fe-DMY) using a metal-polyphenol self-assembly method, involving the coordination of ferric ion (Fe3+) and dihydromyricetin (DMY), then encapsulated Fe-DMY in neutrophil membranes (NM) to form NM@Fe-DMY, which targets to neuroinflammatory regions. NM@Fe-DMY exhibits strong catalase- and superoxide dismutase-like catalytic activities, suggesting its potential to reduce oxidative stress in SAH. This leads to reduced lipid peroxidation, increased expression of glutathione peroxidase 4 and prevented ferroptosis. Furthermore, The NM@Fe-DMY has demonstrated effective penetration of the BBB in vivo, accumulating in SAH injury region and exhibiting significant therapeutic efficacy including neural function recovery and improvement of spatial memory. Importantly, NM@Fe-DMY also induces the polarization of microglia from M1-like to M2-like subtypes, interrupting the detrimental cycle of neuroinflammation in EBI. This study introduces a new NM-wrapped biomimetic nanozyme strategy for effectively targeting neuroinflammatory regions and enhancing the treatment of EBI following SAH.

The effects and mechanisms of two-dimensional V2C and V2CT2 (T = O, F, and OH) on hydrogen adsorption and dissociation properties of MgH2: First-principles calculations

Two-dimensional vanadium carbide (V2C) MXene has been confirmed the excellent catalytic activity on hydrogen storage of magnesium hydride (MgH2) in experimental. In present work, adsorption energy, density of states (DOS), charge density difference, dissociation barrier and dehydrogenation energy of the small MgH2 clusters on V2C and V2CT2 (T = O, F, and OH) were investigated by using density functional theory (DFT). The results revealed that the (MgH2)1 cluster adsorbed on the V2C has the best adsorption energy with −0.91eV and the lengths of Mg–H bonds were increased from 1.71 Å to 1.77 Å. The electronic structure results displayed that the H s states hybridized with the V d states, and the charge transferred from H atoms to V atoms. In addition, the (MgH2)1 cluster could be spontaneously dissociated on the V2C, and the dissociation barriers of (MgH2)2 and (MgH2)4 clusters on the V2C reduced by 1.33 and 1.25 eV than that of pristine (MgH2)2 and (MgH2)4 clusters, respectively. Compared with the pristine (MgH2)4 cluster, the dehydrogenation energies of (MgH2)4 cluster were dramatically promoted by adding V2C. The thermodynamic performance of MgH2 were noticeably improved.

Fe, Cu dual-atom catalysts assisted molecularly imprinted electrochemiluminescence sensor for ultrasensitive detection of trichlorfon

Trichlorfon (TCF) has the possibility of contaminating agricultural crops and posing some health risks to humans. Herein, an electrochemiluminescence (ECL) sensor based on Fe, Cu dual-atom catalysts (Fe/Cu-N-C DACs) and Au@Luminol was developed for the ultrasensitive detection of TCF. Fe/Cu-N-C with diatomic sites has a very high catalytic activity and can be used as a co-reaction accelerator to activate H2O2 to generate a large number of hydroxyl radicals which triggered a strong cathodic ECL signal of luminol. TCF molecularly imprinted polymer (MIP) was further introduced as a specific recognition element, and the interaction between the template molecule and the functional monomer was verified by molecular docking technique. The developed sensing platform was successfully applied to the ultrasensitive detection of TCF with a linear range from 1.0 pg/mL to 5.0 μg/mL with a low detection limit (0.39 pg/mL). This study broadens the application of DACs in ECL sensing.

Engineered Imine Reductase Catalyzed Enantiodivergent Synthesis of Alkylated Amphetamines.

Less steric ketones exhibited low stereoselectivity toward M5 due to their difficulty in restricting the free rotation of the imine intermediate. An engineered enantio-complementary imine reductase from M5 was obtained with catalytic activity. We identified four key residues that play essential roles in controlling stereoselectivity. Two mutants, I149Y-W234L (up to 99%S ee) and L200M-F260M (up to 99%R ee), were achieved, showing excellent stereoselectivity toward the tested substrates, offering valuable biocatalysts for synthesizing alkylated amphetamines.

Green Synthesis of Bimetallic Cu−Cd Nanoparticles and its Catalytic Activity in Pyrido [2,3‐d;6,5‐d] Dipyrimidine Derivatives

AbstractGreen synthesis nanoparticles have gained interest in recent years due to their environmental friendliness and sustainability. The current study focuses on the green synthesis of BMNP using spearmint leaves as a reducing and stabilizing agent. Because of their excellent catalytic characteristics, the synthesized bimetallic nanoparticles function as an effective catalyst in pyrido[2,3‐d:6,5‐d] pyrimidine derivatives. The synthesized nanoparticles are characterized using a variety of techniques, including FT‐IR analysis, SEM & EDX, XRD, and TEM. The FT‐IR study shows a reduction in functional groups in the leaf extract, confirming the metal nanoparticles’ stretching. SEM and EDX studies confirm the shape and elemental composition of bimetallic nanoparticles. XRD investigation showed that the synthesized NPs are crystalline, and the Scherrer equation was used to calculate the average crystallite size. The calculated size was 49 nm. TEM analysis confirms the core‐shell nature of BMNPs. The synthesized nanoparticles acted as a superior catalyst in pyrido[2,3‐d:6,5‐d] dipyrimidines derivatives. in the synthetic procedure, BMNPs enhanced the catalytic activity and reduced the reaction time with more yield, Compared to the previous study. and the synthesized compound [1–5] has been confirmed by FT‐IR, 1H‐NMR, and 13C‐NMR analysis. and it has given better results in in‐vivo anti‐diabetic activity by Streptozotocin nicotinamide. This induced model adult male albino Wistar derivatives show significant fasting blood glucose levels when compared to metformin hydrochloride. and its evaluated molecular docking study, exhibit excellent CDDOCKER energy.

Nanozyme-Based Microfluidic Chip System for pH-Regulated Pretreatment and Sensitive Sensing.

Nanozymes, possessing nanomaterial properties and catalytic activities, offer great opportunities to design sensitive analytical detection systems. However, the low interference resistance of nanozymes poses a significant limitation on the precise detection of target substances. Herein, a nanozyme-based microfluidic chip system for pH-regulated pretreatment and sensitive sensing of cysteine (Cys) is reported. The copper metal-organic framework (Cu MOF) exhibits good cysteine oxidase-like activity at pH 7.0, while demonstrating excellent laccase-like activity at pH 8.0. Taking advantage of the pH-regulated enzyme-like activity, the integrated microfluidic device involving the immobilization of Cu MOF eliminates the interference of dopamine (DA) and accurately detects the target Cys. Compared with the untreated reaction system, the developed nanozyme system shows a significantly improved accuracy in detecting Cys, with an R2 value of 0.9914. This work provides an efficient method to enhance the interference resistance of nanozymes and broadens the application in sample pretreatment.

Structure Remodeling Strategy for Open-Cage NiFe@Fe-bis-PBA with Enhanced Peroxidase-like Activity To Monitor Tumor Markers.

The inherent metal elements and structures of Prussian blue analogue (PBA) nanozymes have restricted their enzyme-mimicking activity. Therefore, the rational regulation of PBA nanozymes to improve their catalytic activity is highly desirable for biosensing applications. Herein, we propose a structure remodeling strategy to construct an open-cage Fe PBA-anchored NiFePBA (NiFe@Fe bis-PBA) nanozyme with significantly enhanced enzyme-mimicking activity. The formation process and mechanism for this bis-PBA nanozyme were studied in detail. Specifically, a cubic NiFePBA precursor was first synthesized and modified with polyvinylpyrrolidone (PVP). With the aid of hydrochloric acid, the added potassium ferricyanide was reduced by PVP and re-coordinated on the surface of NiFePBA to form the NiFe@Fe bis-PBA nanozyme with a special open-cage core-shell structure. The resultant NiFe@Fe bis-PBA nanozyme was further exploited to immobilize secondary antibodies, serving as a novel signal probe for developing highly sensitive electrochemical immunosensors for monitoring tumor markers. The constructed electrochemical immunosensor possesses a very wide linear range of 0.005-100 ng/mL and a low detection limit of 0.89 pg/mL for alpha-fetoprotein with high specificity and acceptable reproducibility and stability. This work offers a general and promising strategy for remodeling PBA nanozymes with a very favorable structure and metal element distribution, which enhances their enzyme-mimicking properties for applications in different fields.

Theoretical investigation of sustainable CO2 electroreduction to high-value products utilizing N-doped/BN-modified Triphenylene-Graphdiyne catalysts

The potential of carbon-based triphenylene-graphdiyne (tpGDY) and its derivatives for the electrochemical CO2 reduction reaction (eCO2R) was comprehensively explored using density functional theory (DFT) calculations. Six variants were studied: pristine tpGDY, tpGDY-BN, tpGDY-N01, tpGDY-N02, tpGDY-N08, and tpGDY-BN-B01. Pristine tpGDY, tpGDY-BN, and tpGDY-N08 exhibited exceptional catalytic activity, efficiently converting CO2 into CO and HCOOH without external energy input. Significantly, N-doped tpGDY catalysts incorporating sp2-hybridized nitrogen atoms at the acetylenic sites (tpGDY-N01 and tpGDY-BN-N01) demonstrated remarkable electrocatalytic activity for the targeted conversion of CO2 to CH3OH. This outstanding performance is further corroborated by the low limiting potentials of −0.18 V and −0.27 V for tpGDY-N01 and tpGDY-BN-N01, respectively, highlighting their economic viability. Furthermore, the feasibility of C2 production (e.g., C2H5OH, C2H4 and C2H6) through C–C coupling of *CHO+*CO intermediate was investigated for tpGDY-N01 and tpGDY-BN-N01. DFT calculations suggest these pathways are achievable but require potentials of 0.84 V and 0.71 V for tpGDY-N01 and tpGDY-BN-N01, respectively. This study demonstrates the efficacy of N-doped tpGDY as a metal-free electrocatalyst for CO2 reduction, enabling the generation of both C1 and C2 products. This discovery holds significant promise for the advancement of sustainable CO2 conversion technologies.

Enhancing the activity and sulfur resistance of CuFeAlOx catalyst via the structure effect for the simultaneous removal of Hg0 and NO at wide temperature

The efficient strategy for improving SO2 resistance and catalytic activity is structural modification. Herein, the CuFeAlOx catalysts with different structures, including one-dimensionally disordered mesoporous nanoparticles structure (CuFeAl-N), one-dimensionally ordered mesoporous nanoparticles structure (CuFeAl-C), three-dimensionally ordered porous honeycomb-like structure (CuFeAl-P) and three-dimensionally ordered porous flower-like structures (CuFeAl-CP), were synthesized via a template method to investigate structure effect on activity and sulfur resistance of the catalyst for simultaneously removing NO and Hg0 at wide temperature. The results showed that the various surface characteristics resulted in distinct behaviours with regards to SO2 tolerance. CuFeAl-CP and CuFeAl-C exhibits excellent SO2 resistance, but CuFeAl-N catalyst presents poor SO2 resistance. The CuFeAl-CP with the flower-like structure possesses large specific surface area, which can expose more active sites and exhibited highly dispersed active component. More importantly, it reacts with SO2 to generate reactive sulfate providing additional acid sites, which significantly promotes high-temperature catalytic performance. One-dimensionally ordered mesoporous and three-dimensionally ordered porous effectively facilitates mass transfer of reactants and ammonium sulphate decomposition, thereby inhibiting surface sulfation and ammonium sulfate species deposition. This work lays the foundation for developing highly efficient SCR catalysts that are tolerant to SO2.

A new type of pentagonal structure HgS2 monolayer with abundant active sites and low Gibbs free energy for photocatalytic water splitting

Discovery of new two-dimensional (2D) materials not only has important fundamental research significance but also has promising application prospects. Through systematic structure searching combined with density functional theory calculations and simulations, we predict a new 2D monolayer HgS2 material featuring with a previously unreported type of pentagonal structure with orthorhombic P21212 symmetry. The penta-HgS2 monolayer shows good thermal, thermodynamic, mechanical and dynamic stabilities, exhibiting ferroelastic phase transition with an ultralow switching energy barrier (about 1 meV/atom), high ultimate strength of 12 N/m, moderate indirect band gap of 2.25 eV. In addition, the penta-HgS2 monolayer shows significantly anisotropic carrier mobility with a large anisotropy ratio of 98.5 along the y direction. More importantly, the penta-HgS2 monolayer exhibits abundant catalytic active sites, low Gibbs free energy (ΔGH ranging from 0.656 to 1.687 eV) for hydrogen evolution reactions, excellent solar light absorption capacity (∼105 cm−1) with the solar-to-hydrogen efficiency reaching up to 11.83%. The excellent ultimate tensile ability and the ultralow ferroelastic phase transition energy barrier implies penta-HgS2 monolayer material can be used to manufacture flexible mechanical and nanoelectronic devices. The suitable band edge alignments, ultrahigh carrier mobility anisotropy, high catalytic activity and excellent visible light adsorption performance indicate that penta-HgS2 monolayer is a promising candidate photocatalyst for high-performance photocatalytic water splitting. The present work not only supplements a new member to the 2D pentagonal structure material family, but also points out its promising applications in nanoscale devices and photocatalytic hydrogen productions.

Anchoring cobalt dual-atom pairs on open hollow-structured carbon via a facile in-situ synthetic strategy for enhanced advanced oxidation processes

Atomically dispersed catalysts offer unprecedented opportunities for high-efficiency Fenton-like oxidation of organic pollutants in water. However, the hazardous metal leaching of atomically dispersed catalysts hinders their practical application for wastewater treatment, while the inaccessible interior active sites in carbon substrates have been commonly overlooked. Herein, we develop a straightforward approach for tightly anchoring cobalt dual-atom pairs on nitrogen-doped open hollow carbon structure (Co-NOHC) via an in-situ polyelectrolyte nanosphere-guided strategy. The unique open hollow carbon structure benefits the electron/mass transfer and maximizes the exposure of active sites. As a result, the as-synthesized Co-NOHC exhibits outstanding peroxymonosulfate activation activity and Fenton-like performance in oxidation by taking rhodamine B degradation as an example. Remarkably, the turnover frequency of the Co-NOHC is 6.5, 26.5, and 9.3 times higher than that of the Co2+, cobalt, and its oxides, respectively, and its catalytic activity also greatly outperforms the pristine zeolitic-imidazole frameworks derived Co-based atomically dispersed catalysts. More importantly, benefitted from the stable anchoring of cobalt dual atoms, the Co2+ leaching from the Co-NOHC is greatly alleviated, as low as 0.1 mg/L after the catalytic reaction, showing outstanding stability as compared to most atomically dispersed catalysts. Furthermore, the reactive active species, including SO4−, OH and O2− radicals, and electron-transfer mechanism are demonstrated to dominate the rhodamine B removal. This work offers a new consideration for promoting the development of the advanced catalysts and their potential applications in advanced oxidation process.