Effect Of Nitrogen Doping Research Articles

Engineering surface state density of monolayer CVD grown 2D MoS2 for enhanced photodetector performance.

This study demonstrates the effect of nitrogen doping on the surface state densities (Nss) of monolayer MoS2 and its effect on the responsivity and the response time of the photodetector. Our experimental results shows that by doping monolayer MoS2 by nitrogen, the surface state (Nss) increases thereby increasing responsivity. The mathematical model included in the paper supports the relation of photocurrent gain and its dependency on trap level which states that the increasing the trap density increases the photocurrent gain and the same is observed experimentally. The experimental results at room temperature revealed that nitrogen doped MoS2 have a high NSS of 1.63 X 1013 states/m2/eV compared to undoped MoS2 of 4.2 x 1012 states/m2/eV. The increase in Nss in turn is the cause for rise in trap states which eventually increases the value of photo responsivity from 65.12 A/W (undoped MoS2) to 606.3 A/W (nitrogen doped MoS2). The response time calculated for undoped MoS2 was 0.85 sec and for doped MoS2 was 0.35 sec. Finally, to verify the dependence of surface states on the responsivity, the surface states were varied by varying temperature and it was observed that upon increment in temperature, the surface states decreases which causes the responsivity values also to decrease.

Effects of Nitrogen Doping on Microstructures and Irradiation Resistance of Ti–Zr–Nb–V–Mo Refractory High-Entropy Alloy

Effects of Nitrogen Doping on Microstructures and Irradiation Resistance of Ti–Zr–Nb–V–Mo Refractory High-Entropy Alloy

Fluorine, nitrogen doping, and triaxial strain effects on the structural stability and hydrogen storage properties of lithium hydride LiH: DFT investigation

This research comprehensively addressed various aspects of hydrogen storage, with a focus on metallic hydride materials, lithium hydride LiH, one of the lightest reversible metal hydrides, boasts a remarkable gravimetric density of up to 12.67 wt.% and an impressive volumetric capacity of 4.95 Kg/100L. Despite these strengths, challenges accompany lithium hydride, such as its elevated formation energy and a high desorption temperature around 600K–700K. In this work, ab initio calculations based on Density Functional Theory (DFT) were used to study the thermodynamic and electronic properties of this material with the aim of reducing the high temperature of decomposition while preserving a significant gravimetric capacity and satisfactory stability in line with the U.S. Department of Energy (DOE) standards for solid-state hydrogen storage (ΔHf = - 40 KJ/mol.H2 and Td = 289 K–393 K). The results obtained show the influence of the doping effect firstly (Li1-xFxH, Li1-xNxH) on the improvement of the hydrogen storage properties, with a percentage gain of 50.64% for 4% doping with F and 49.08% for 8% doping with N. Secondly, a 38.63% gain in thermodynamic stability was observed by applying triaxial compressive stresses to the LiH compound.

Nitrogen admixture effects on growth characteristics and properties of carbon nanowalls

The plasma functionalization of carbon nanowalls (CNWs) is of great interest due to their potential applications in electron field emission and energy storage devices. In this study, the effects of nitrogen on the growth and properties of CNWs are thoroughly investigated by varying a wide range of the N2 concentrations in the CH4/H2/N2 discharge plasma. Nitrogen-doped carbon nanowalls (N-CNWs) were synthesized in a single-step growth using the hydrogen radical injection plasma-enhanced chemical vapor deposition technique. The formation of dense N-CNWs was found to be enhanced by nitrogen and was three times higher in the sample with a 150 sccm N2 flow rate than in the sample without N2 addition (N-0). As the N2 concentration increased from 0 to 200 sccm, the morphology of CNWs changed from relatively straight to curly-like nanowall structures. A high-resolution optical emission spectroscopic observation shows that as N2 flow increased, CN radicals became the dominant species, suppressing the formation of C2 and CH. Photoelectron spectroscopy analysis revealed the nitrogen doping effect on graphene layers at high N2 concentrations. According to Raman and Transmission Electron Microscopy analyses, the N-CNWs had more branched and thicker nanowalls with higher defect concentrations than the N-0 sample. The wettability of N-CNWs was improved, particularly for the sample with a N2 flow rate of 150 sccm.

The Effect of Sulfur and Nitrogen Doping on the Oxygen Reduction Performance of Graphene/Iron Oxide Electrocatalysts Prepared by Using Microwave-Assisted Synthesis.

The synthesis of novel catalysts for the oxygen reduction reaction, by means of a fast one-pot microwave-assisted procedure, is reported herein and deeply explained. In particular, the important role of doping atoms, like sulfur and nitrogen, in Fe2O3-reduced graphene oxide nanocomposites is described to address the modification of catalytic performance. The presence of dopants is confirmed by X-ray Photoelectron Spectroscopy analysis, while the integration of iron oxide nanoparticles, by means of decoration of the graphene structure, is corroborated by electron microscopy, which also confirms that there is no damage to the graphene sheets induced by the synthesis procedure. The electrochemical characterizations put in evidence the synergistic catalysis effects of dopant atoms with Fe2O3 and, in particular, the importance of sulfur introduction into the graphene lattice. Catalytic performance of as-prepared materials toward oxygen reduction shows values close to the Pt/C reference material, commonly used for fuel cell and metal-air battery applications.

Uncovering optical, magnetic, and electrical properties of epitaxial nitrogen-doped lithium ferrite films

The powerful means of nitrogen doping has been applied to perovskite, rocksalt, anatase, and fluorite oxides to tailor crystal structures, electronic/chemical states, and resultant physical/chemical properties for electronic/optical/magnetic device, catalysis, and energy conversion. However, it is rare for nitrogen-doped spinel oxides, especially for spinel ferrites. Here, we take spinel lithium ferrite (LiFe5O8) as an archetype to elucidate the nitrogen doping effect on the optical, magnetic, and electrical properties. The nitrogen dopants in lithium ferrite oxynitride (LiFe5O8-xNy) epitaxial films have been systematically manipulated by adjusting the deposition atmospheres during sputtering growth. Remarkably, nitrogen doping leads to a significant enhancement in both light absorption (approximately twice as enhanced at 2.1 eV) and electrical performance (up to 6 order enhancement) for lithium ferrites. The combined experimental and theoretical studies reveal that the nitrogen doping effect can effectively narrow the bandgap and create in-gap states that give rise to enhanced light absorption and electrical performance. Our study sheds light on a profound understanding of nitrogen doping-tailored crystal and electronic structures of spinel ferrites and provides a novel, easy, and effective route to magnetic semiconducting ferrite oxynitrides with boosted light absorption and electrical performance, which can be beneficial to spintronic and photochemistry applications.

Effects of nitrogen doping on lithium polysulfide anchoring by activated carbon derived from palm kernel shell

Effects of nitrogen doping on lithium polysulfide anchoring by activated carbon derived from palm kernel shell

Durability of S- and N-doped graphene nanoplatelets for electrode performance in solid-state batteries

The main emphasis of the present Highlight paper is to summarise reported works aiming to understand the effect of sulfur and nitrogen doping on graphene nanoplatelets for high capacity electrodes in solid-state rechargeable energy storage devices.

Effect of dual Nitrogen doping on the electronic, thermodynamic, transport and thermoelectric properties of graphene

Electronic, thermodynamic, transport, and thermoelectric properties of pristine graphene (C8) and graphene doped with dual nitrogen (N) atoms in three different configurations were theoretically studied. All three configurations display a direct band gap and are n-type semiconductors. Notably, at room temperature, N3-doped graphene has a greater Seebeck coefficient (S) than C8, although N1 and N2 have lower S values. Furthermore, the power factor (PF) for all three structures rapidly increases, especially at high temperatures, with C8's PF decreasing at 300 K. For N1, N2, and N3, the electronic thermal conductivity (κe) follows the Wiedemann-Franz rule, increasing with increasing temperature. Due to N defect-induced heat transfer scattering, lattice thermal conductivity (κL) diminishes exponentially with temperature. The figure of merit (ZT) for N3 doping peaks at 550 K, outperforming N1 and N2 by a large margin (103-106 times) and then drops at higher temperatures due to electronic thermal conductivity impacts.

Significant Differences in the Effects of Nitrogen Doping on Pristine Biochar and Graphene-like Biochar for the Adsorption of Tetracycline.

To improve the adsorption efficiency of pollutants by biochar, preparing graphene-like biochar (GBC) or nitrogen-doped biochar are two commonly used methods. However, the difference in the nitrogen doping (N-doping) effects upon the adsorption of pollutants by pristine biochar (PBC) and GBC, as well as the underlying mechanisms, are still unclear. Take the tetracycline (TC) as an example, the present study analyzed the characteristics of the adsorption of TCs on biochars (PBC, GBC, N-PBC, N-GBC), and significant differences in the effects of N-doping on the adsorption of TCs by PBC and GBC were consistently observed at different solution properties. Specifically, N-doping had varied effects on the adsorption performance of PBC, whereas it uniformly improved the adsorption performance of GBC. To interpret the phenomenon, the N-doping upon the adsorption was revealed by the QSAR model, which indicated that the pore filling (VM) and the interactions between TCs with biochars (Ead-v) were found to be the most important two factors. Furthermore, the density functional theory (DFT) results demonstrated that N-doping slightly affects biochar's chemical reactivity. The van der Waals (vdWs) and electrostatic interactions are the main forces for TCs-biochars interactions. Moreover, N-doping mostly strengthened the electrostatic interactions of TCs-biochars, but the vdWs interactions of most samples remained largely unaffected. Overall, the revealed mechanism of N-doping on TCs adsorption by biochars will enhance our knowledge of antibiotic pollution remediation.

Effects of Oxygen Defects in Zr Oxide-Based Thin Films on Oxygen Reduction Reaction in Acidic Media

The use of carbon-supported platinum as cathode catalysts of polymer electrolyte fuel cells has some problems such as high cost and low amount of resources of platinum. Therefore, we have attempted to develop substitute of platinum based on group 4 metal oxides. In the case of Zr oxide-based powder catalysts, we found that zirconium oxide-based compounds with oxygen defects and deposited carbon derived from organometallic precursors had definite activity of oxygen reduction reaction (ORR) [1][2]. However, the ORR activities of these catalysts still remain low. In order to increase the ORR activity drastically, it is necessary to clarify the catalyst design. This requires an understanding of the active sites and the electron conduction path separately, which were not separated in powder catalysts. On the other hand, Sugino et al. investigated the effect of oxygen vacancies and nitrogen doping on the active site based on first-principles calculations [3]. Defects by oxygen vacancies and nitrogen dopants were introduced into the tetragonal ZrO2(101) slab. It was found that the energy barrier of the rate-determining step, or the removal of adsorbed OH, was comparable to (or only slightly lower than) that of the pristine surfaces, indicating that defects play only a minor role in enhancing the ORR activity. In other words, it was suggested that oxygen vacancies and nitrogen dopants contributed to the emergence of ORR activity by enhancing the electrical conductivity of ZrO2 rather than by forming high quality active sites. Simple models are suitable for experimentally confirming the results of theoretical calculations and for understanding the active sites and the electron conduction paths separately. Therefore, we attempted to prepare nitrogen doped ZrOx nanofilms by RF magnetron sputtering method with different targets and atmospheres and to investigate their potential as model electrodes.ZrOx thin films of ca. 3-5 nm thickness were prepared by RF magnetron sputtering method using glassy carbon (GC) plates as substrates and ZrN or Zr metal plates as targets under Ar, Ar+O2 and Ar+N2. The sputtering power, the deposition time, and the substrate heating temperature were 100 W, 10 min, and 300 ℃, respectively. The flow rates of Ar, O2, and N2 gas were controlled to keep the total chamber pressure at approximately 0.6 Pa. When the gases were mixed, the partial pressure ratio was set to 1:1. Electrode prepared with a ZrN target in Ar was denoted as "ZrN_Ar", and electrodes prepared with a Zr target in Ar:O2 and Ar:N2 were denoted as "Zr_Ar+N2" and "Zr_Ar+O2", respectively. A conventional three-electrode cell was used for electrochemical measurements with Reversible Hydrogen Electrode (RHE) as a reference and a GC plate as a counter electrode in 0.5 M sulfuric acid at 30 ℃. The oxygen reduction current density i ORR (geometric area standard) was calculated by subtracting the current in N2 from the current in O2.Figure 1 shows the effect of sputtering condition on potential-ORR current curves of the ZrOx thin film electrodes. For comparison, the result of the GC substrate only is also plotted as "GC only." The ORR activity of the ZrN_Ar was lower than that of the GC only. In addition, the current of the steady-state cyclic voltammogram of the ZrN_Ar was smaller than that of the GC only. This may be due to the electrochemical oxidation of ZrN surface and the formation of an insulating layer without active sites, presumably Zr hydroxide. On the other hand, the onset potential of the Zr_Ar+N2 and the Zr_Ar+O2 for the ORR were higher than that of the GC only and the Zr_Ar+N2 showed highest ORR activity. The steady-state cyclic voltammograms of the Zr_Ar+N2 and the Zr_Ar+O2 were larger than that of GC only, revealing that these electrodes might have high conductivities. In addition, XPS measurements suggest that the Zr_Ar+N2 contains nitrogen and the Zr_Ar+N2 and the Zr_Ar+O2 have oxygen vacancies. These results suggested that their high ORR activities were caused by nitrogen doping and oxygen defects. Therefore, the electrodes prepared by RF magnetron sputtering method may be able to separate the active sites from the electron conduction by changing the sputtering conditions such as film thickness.AcknowledgementThe authors thank the financial support of the New Energy and Industrial Technology Development Organization (NEDO).References(1) A. Ishihara et al., J. Phys. Chem. C, 123, 18150 (2019).(2) M. Chisaka et al., ACS Omega, 2, 678 (2017).(3) S. Muhammady et al., J. Phys. Chem. C, 126, 15662 (2022). Figure 1

Synergistic effects of hierarchical porous structures and ultra-high pyridine nitrogen doping enhance the oxygen reduction reaction electrocatalytic performance of metal-free laminated lignin-based carbon

Construction of non-metallic biomass-carbon based catalysts for fuel cell air cathode applications has attracted great attention in recent years. In this work, a convenient and clean technique was developed to fabrication nitrogen-doped lignin-based hierarchical porous lamellar carbon (N-LHPC) via lignin as the carbon precursor, melamine/urea as the nitrogen source and ZnC2O4.2H2O as the chemical activator. The N-LHPC has a high specific surface area (491.5 m2 g−1) and macroporous/mesoporous/microporous structures. The nitrogen doping of N-LHPC can reach 16.37 wt%, with a high pyridinic nitrogen content of 41.39 at.%. N-LHPC exhibits a high half-wave potential (0.87 V) and a large limiting current density (5.75 mA cm−2) in 0.1 mol KOH media which is comparable to the commercial Pt/C catalysts. Furthermore, N-LHPC was assembled as air cathode catalyst for Zn-air batteries to evaluate its practical catalytic performance, and the power density was as high as 191 mW cm−2, which was superior to the 20 wt% Pt/C electrocatalyst. This research demonstrates that lignin is a promising carbon source for the fabrication of high catalytic activity and economical electrocatalysts for energy storage systems.

Effect of N Content on the Microstructure and Impact Properties of Normalized Vanadium Micro-Alloyed P460NL1 Steel

In this work, the effect of nitrogen doping on vanadium micro-alloyed P460NL1 steel is studied in terms of microstructures and impact toughness. As the nitrogen content increased from 0.0036% to 0.0165%, the number of V (C,N) particles increased. The fine precipitates of V (C,N) effectively pin the prior austenite grain boundary, resulting in the refinement of the austenite grain. The intragranular and intergranular V-containing coarse particles enhanced the nucleation of intragranular ferrite and the grain boundaries of polygonal ferrite during air cooling. Accordingly, the proportion of heterogeneously nucleated ferrite increased, and the grain size of ferrite decreased. Notably, the size of the pearlite microstructure decreased, and the bainite microstructure appeared with a high doping of N. With the increase in N content, the impact toughness of vanadium micro-alloyed P460NL1 steel was enhanced. This can be attributed to the refinement of ferrite and the reduction in pearlite, which, in turn, was ascribed to the increase in nitrogen.

Enhance the durability of the oxygen reduction reaction catalyst through the synergy of improved graphitization and nitrogen doping of carbon carrier

The energy crisis has highlighted the need for low-cost, highly active, and durable catalysts for Proton Exchange Membrane Fuel Cells (PEMFCs). Accordingly, we have developed a highly durable composite carbon carrier material, ECP600@NC, through pyrolyzing polyaniline coated on commercial carbon black ECP600, and supported the Pt nanoparticles (NPs) on ECP600@NC to prepare catalyst Pt/ECP600@NC. Compared with the catalyst Pt/ECP600, the electrochemical active surface area (ECSA) of Pt/ECP600@NC (94.1 m2·gPt−1) increased by 15% and the mass activity (MA) of Pt/ECP600@NC (343.9 mA·mgPt−1) increased by 142%. After 30,000 cycles carbon and Pt attenuation tests, the ECSA retention rate of Pt/ECP600@NC increased by 40% compared with Pt/ECP600@NC, and the MA retention rate of Pt/ECP600@NC increased by 15%. It is the synergistic effect of higher graphitization degree and nitrogen doping of the carbon carrier that improves the performance and durability of Pt/ECP600@NC. This work provides a promising method to optimize the catalysts for PEMFCs.

Effect of Nitrogen Doping on the Electrochemical Properties of Lithium Battery Anode of Activated Carbon

Effect of Nitrogen Doping on the Electrochemical Properties of Lithium Battery Anode of Activated Carbon

Quantitative simulationSimulation of nitrogen doping effects on benzene selective adsorption by activated carbon in aqueous conditions

Investigating the impact of nitrogen doping on the selective adsorption of benzene on activated carbon under aqueous conditions holds significant importance in regulating nitrogen content on activated carbon precisely and enhancing benzene adsorption in the air. This study utilizes quantum chemical simulation to systematically compute the pairwise interactions of pyridine nitrogen, pyrrole nitrogen, graphite nitrogen, and their coexistence on carbon materials, including electrostatic potential, van der Waals potential, and polarity changes. We examine the adsorption of benzene and water on nitrogen-doped carbon materials and calculate the type and proportion of weak interactions in the adsorption process through energy decomposition analysis. Visual analysis of weak interactions is conducted via independent gradient scatter plots and isosurface plots. Based on this research, we investigate the influence of nitrogen doping on the competitive adsorption of benzene and water on carbon materials using adsorption energy and configuration changes. Our findings reveal that nitrogen doping disrupts the uniform electrostatic potential distribution and polarity of carbon materials. Specifically, graphite nitrogen inhibits water molecule adsorption by enhancing mutual repulsion and weakening dispersion and electrostatic interactions, consequently promoting benzene adsorption on carbon materials. Moreover, hydrogen bonds form between pyridine nitrogen, pyrrole nitrogen, and water, making carbon materials more hydrophilic. However, when combined with graphite nitrogen, this increases the negative van der Waals potential of carbon materials, further enhancing benzene adsorption. Experimental results align with the simulation, reinforcing the significance of this research in developing efficient activated carbon adsorbents for benzene under aqueous conditions.

Physical Origin of Color Changes in Lutetium Hydride under Pressure

Recently, near-ambient superconductivity was claimed in nitrogen-doped lutetium hydride (LuH3–δ N ε ). Unfortunately, all follow-up research still cannot find superconductivity signs in successfully synthesized lutetium dihydride (LuH2) and N-doped LuH2±x N y . However, a similar intriguing observation was the pressure-induced color changes (from blue to pink and subsequent red). The physical understanding of its origin and the correlation between the color, crystal structure, and chemical composition of Lu–H–N is still lacking. In this work, we systematically investigated the optical properties of LuH2 and LuH3, and the effects of hydrogen vacancies and nitrogen doping using the first-principles calculations by considering both interband and intraband contributions. Our results demonstrate that the evolution of reflectivity peaks near blue and red light, which is driven by changes in the band gap and Fermi velocity of free electrons, resulting in the blue-to-red color change under pressure. In contrast, LuH3 exhibits gray and no color change up to 50 GPa. Furthermore, we investigated the effects of hydrogen vacancies and nitrogen doping on its optical properties. Hydrogen vacancies can significantly decrease the pressure of blue-to-red color change in LuH2 but do not have a noticeable effect on the color of LuH3. The N-doped LuH2 with the substitution of a hydrogen atom at the tetrahedral position maintains the color change when the N-doping concentration is low. As the doping level increases, this trend becomes less obvious, while other N-doped structures do not show a blue-to-red color change. Our results can clarify the origin of the experimental observed blue-to-red color change in lutetium hydride and also provide a further understanding of the potential N-doped lutetium dihydride.

Surface engineering of ZnO electrocatalyst by N doping towards electrochemical CO2 reduction

The discovery of efficient, selective, and stable electrocatalysts can be a key point to produce the large-scale chemical fuels via electrochemical CO2 reduction (ECR). In this study, an earth-abundant and nontoxic ZnO-based electrocatalyst was developed for use in gas-diffusion electrodes (GDE), and the effect of nitrogen (N) doping on the ECR activity of ZnO electrocatalysts was investigated. Initially, a ZnO nanosheet was prepared via the hydrothermal method, and nitridation was performed at different times to control the N-doping content. With an increase in the N-doping content, the morphological properties of the nanosheet changed significantly, namely, the 2D nanosheets transformed into irregularly shaped nanoparticles. Furthermore, the ECR performance of ZnO electrocatalysts with different N-doping content was assessed in 1.0 M KHCO3 electrolyte using a gas-diffusion electrode-based ECR cell. While the ECR activity increased after a small amount of N doping, it decreased for higher N doping content. Among them, the N:ZnO-1 h electrocatalysts showed the best CO selectivity, with a faradaic efficiency (FECO) of 92.7% at −0.73 V vs. reversible hydrogen electrode (RHE), which was greater than that of an undoped ZnO electrocatalyst (FECO of 63.4% at −0.78 VRHE). Also, the N:ZnO-1 h electrocatalyst exhibited outstanding durability for 16 h, with a partial current density of −92.1 mA cm−2. This improvement of N:ZnO-1 h electrocatalyst can be explained by density functional theory calculations, demonstrating that this improvement of N:ZnO-1 h electrocatalyst comes from (i) the optimized active sites lowering the free energy barrier for the rate-determining step (RDS), and (ii) the modification of electronic structure enhancing the electron transfer rate by N doping.

Effects of Nitrogen Doping on Pulling Rate Range of Defect-Free Crystal in CZ Silicon

We investigated the effect of nitrogen doping on the pulling rate range of defect-free crystal in silicon with a diameter of 200 mm. It was found that the pulling rate range of defect-free crystal in nitrogen-doped Czochralski silicon is wider and the pulling rate (defect free) is lower than it is in non-nitrogen-doped Czochralski silicon. Under the experiment, the pull rate was from 0.67 mm/min~0.58 mm/min to 0.65 mm/min~0.54 mm/min. To further confirm the above experimental analysis, a numerical simulation process of nitrogen-doped Czochralski and non-nitrogen-doped Czochralski in an industrial system was performed. The V/G value along the S/L interface was the same for both models, but the distribution of Cvi (concentration of vacancy–concentration of self-interstitial) for nitrogen-doped Czochralski crystal silicon was more uniform and flat in a nitrogen-doped single crystal. Furthermore, the nitrogen-doped Czochralski crystal silicon had a smaller void size and a higher oxygen precipitation density. The experimental results are in good agreement with the numerical simulation results.

The role of nitrogen-doping on the electrochemical behavior of MOF-derived carbons in ionic liquid electrolytes

Metal-organic frameworks (MOFs) derived nanoporous carbons have been intensively studied as electrode materials for electric double-layer capacitors. However, the current research on MOF-derived carbons were mainly focused on investigating electrochemical performances of supercapacitors in aqueous electrolytes, and there were only a few studies involved ionic liquids electrolytes. In addition, the research of nitrogen doping effect on MOF-derived carbons in ionic liquids electrolytes has rarely been reported. Nitrogen doping is considered to be the common and effective way to improve the electrochemical performances of carbonaceous electrodes because it can not only enhance the electrical conductivity but also bring about pseudocapacitances in aqueous electrolytes. However, the nitrogen doping effect in ionic liquids electrolytes need to be further investigated especially for MOF-derived carbons with large quantities of micropores. In this study, MOF-derived nitrogen-doped carbons were synthesized by carbonization of urea functionalized Zn-MOF-74, and their electrochemical behavior in EMIMBF4 and EMIMTFSI ionic liquid electrolytes were investigated. The nitrogen-doping degree was tuned by adjusting the amount of urea. Electrochemical test showed that nitrogen-doped carbons exhibited a maximum capacitance enhancement of 24.4 % than pristine sample in ionic liquid electrolytes. Nevertheless, nitrogen-doping contributed few pseudocapacitances in ionic liquid electrolytes, and the enhanced electrochemical performances could be ascribed to the increased electrical conductivity and the matched pore structures.