Enhanced photocatalytic properties of a chemically modified blue phosphorene

It is high time to placate the peak demand for an efficient, economic and green fuel in the form of H₂ through photocatalytic water splitting. Several low dimensional materials have been explored for their photocatalytic properties on account of their surface to volume ratio. The present study illustrates the excellent photocatalytic potential of a two-dimensional material, viz. a chemically tempered blue-phosphorene sheet, with single atom thickness and high carrier mobility. Metal-free element, sulphur, is explored as a dopant in a 32-atom blue-phosphorene sheet. The dopant is inserted at three locations viz. central, edge and central edge positions with varying concentrations from 3.125% to 18.75% (corresponding to n = 1 to 6 sulphur atoms within a 32-atom blue-phosphorene sheet, P_32−nS_n). The cohesive energy studies predict the higher stability of even number S doped sheets as compared to their odd counterparts. Photocatalytic activity is studied in terms of band gap and band alignment for different concentrations of the former. Studies reveal that edge doping demonstrates better water molecule activation independent of S atom concentration. The edge doped systems not only provide the chemical activity to activate water, but also show feasible HER overpotentials of 1.24–1.29 eV at neutral medium. Finally, this work opens up a driving lead of non-corrosive catalysts for water molecule splitting.

Rate of photocatalysis depends on how well the structures can check the electron–hole recombination.     

Enhanced photocatalytic activity in ZnO nanoparticles developed using novel Lepidagathis ananthapuramensis leaf extract

The present study focuses on the green synthesis of zinc oxide nanoparticles (ZnO NPs) using a novel Lepidagathis ananthapuramensis (LA) leaf extract and a systematic study on the photocatalytic degradation of methylene blue (MB) dye. The structural, thermal, morphological, optical, and surface area analysis of prepared ZnO NPs were examined using X-ray diffraction (XRD), UV-visible spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, thermogravimetric analysis (TGA), field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDAX) and high-resolution transmission electron microscopy (HR-TEM). The LA stabilised ZnO NPs produced NPs with diverse morphologies, low band gap and cost-effective high yield of production. A systematic study has been carried out to determine the crystallinity and crystallite size of ZnO NPs based on the concentration of Zn(NO₃)₂ precursor, concentration of LA leaf extract, calcination temperature and calcination time. The crystallinity and crystallite size of ZnO NPs were evaluated based on the XRD technique. The photocatalytic activity of ZnO NPs was thoroughly investigated for the degradation of MB dye based on various physicochemical parameters such as reaction time, concentration of catalyst, concentration of precursors, concentration of LA extract, concentration of MB, calcination temperature and calcination time. These systematic photocatalytic studies followed green protocols and provided an excellent photocatalytic efficiency result of 96–98.5% towards the decomposition of MB. Hence, this material can work as a potential candidate for waste water treatment by also degrading other toxic dyes.

Focussing on the green synthesis of ZnO NPs using a novel Lepidagathis ananthapuramensis (LA) leaf template and its photocatalytic activity.     

Pyridylbenzimidazole based Re(i)(CO)3 complexes: antimicrobial activity,spectroscopic and density functional theory calculations

fac-[ReBr(CO)₃(L^1,2)] L¹ = 1-ethyl-2-(pyridin-2-yl)benzimidazole (1) and L² = 1-[(pyridin-2-yl) benzimidazole]-propyl-sulfonic acid (2), fac-[Re₂Br₂(CO)₆L³] (3) L³ = 1,1′-(hexane-1,6-diyl)bis[2-(pyridin-2-yl)1H-benzimidazole] and fac-[ReBr(CO)₃(L^4,5-κ²N¹N²)] (L⁴ = 2,6-bis(benzimidazol-2′-yl)pyridine (4) and L⁵ = 2,6-bis(1-ethyl-benzimidazol-2′-yl)pyridine (5) were synthesized and fully characterized using different spectrocopic and analytical tools. The spectrocopic data showed coordination of L^1–3 to fac-ReBr(CO)₃via the benzimidazole and pyridine N-atoms. For 4 and 5, the absence of a two-fold axis of symmetry for L^4,5 in the ¹H NMR spectra reflect the κ²N¹,N² mode of coordination. The electronic properties of 1–5 were investigated by time-dependent density functional theory calculations in the singlet and triplet states. The ligands and their Re(i) complexes were assessed for their potential antimicrobial activity. Compound 5 was screened against non-malignant cell line (noncancerous human embryonic kidney cell line (HEK293)) as well as evaluated for its blood compatibility.

Mono- and binuclear pyridylbenzimidazole based Re(i) tricarbonyl complexes exhibited antibacterial activity against Gram(+) bacterium. TDDFT calculation, in singlet and triplet states, assigned the lowest energy transition to MLCT and MLCT/³IL, respectively.     

Enhanced photocatalytic and antibacterial activity of plasma-reduced silver nanoparticles

A non-thermal atmospheric pressure plasma jet has been used for the green synthesis of highly dispersed colloidal silver nanoparticles. The reducing species such as hydrogen radicals and hydrated electrons are identified, and the change in the solution pH is studied during AgNP formation. The structural properties and size of the plasma-reduced silver nanoparticles are characterized via X-ray diffraction, ultraviolet-visible spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The size of the colloidal AgNPs is tuned by adjusting the initial concentration of AgNO₃. The effect of terephthalic acid, a hydroxyl radical scavenger, on the reduction of Ag⁺ ion is studied. The typical catalytic activity data indicate the better performance of the plasma-reduced colloidal Ag nanoparticles than that obtained from the chemical reduction method. The antibacterial activity of the plasma-reduced Ag nanoparticles also shows a better performance than that of the chemically reduced AgNPs, highlighting the potential of the plasma reduction approach for the synthesis of metal nanoparticles, which are stable even after 30 days without a stabilizing agent. Additionally, the effects of hydroxyl scavengers (isopropyl alcohol) and Fenton''s reagent (Fe²⁺ salt) on CV degradation are studied.

A non-thermal atmospheric pressure plasma jet has been used for the green synthesis of highly dispersed colloidal silver nanoparticles.     

Thermoelectric properties of heavy fermion CeRhIn5 using density functional theory combined with semiclassical Boltzmann theory

Experimental evidences show that Ce-based compounds can be good candidates for thermoelectric applications due to their high thermoelectric efficiencies at low temperatures. However, thermoelectric properties have been studied less than the other properties for CeRhIn₅, a technologically and fundamentally important compound. Thus, we comprehensively investigate the thermoelectric properties, including the Seebeck coefficient, electrical conductivity, electronic part of thermal conductivity, power factor and electronic figure of merit, by a combination of quantum mechanical density functional and semiclassical Boltzmann theories, including relativistic spin–orbit interactions using different exchange–correlation functionals at temperatures T ≤ 300 K for CeRhIn₅ along its a and c crystalline axes. The temperature dependences of the thermoelectric quantities are investigated. Our results reveal a better Seebeck coefficient, electrical conductivity, power factor and thermoelectric efficiency at T ≪ 300, in agreement with various other Ce-based compounds, when a high degree of localization is considered for the 4f-Ce electrons. The Seebeck coefficient, power factor and thermoelectric efficiency are made more efficient near room temperature by decreasing the degree of localization for 4f-Ce electrons. Our results also show that the thermoelectric efficiency along the a crystalline axis is slightly better than that of the c axis. We also investigate the effects of hydrostatic pressure on the thermoelectric properties of the compound at low and high temperatures. The results show that the effects of imposing pressure strongly depend on the degree of localization considered for 4f-Ce electrons.

Consistent with experimental data, theoretical thermoelectric results calculated by our developed strategy show that CeRhIn₅ is a good candidate for thermoelectric cooling applications due to its high thermoelectric efficiency at low temperatures.     

不同pH值纳米羟基磷灰石复合根充糊剂的体外抑菌性

背景：目前临床应用的根管充填糊剂抗菌作用有限,仃仵组织刺激性强、成形困难、根管封闭性较差及易降解等缺点。目的：比较不同pH值纳米羟基磷灰石复合根充糊刺对感染根臀常见菌的体外抑菌作用。方法：建立体外根管粪肠球菌、白色念球荫感染模型,评价pH8纳米羟基磷灰石糊剂、pH9纳米羟幕磷扶“糊剂、pH10纳米黔基磷灰钉糊刑存离体牙根管内的抗菌作用,并以氧化锌丁香油做对照。结果与结论：所有根充糊剂均其有抑荫作用。各pH值纳米砼基磷灰石糊剂对粪肠球菌抑制作用实验组优于氧化锌丁香油组（P〈0．05）,不同pH值纳米羟慕磷灰石纰组间比较差异无显著性意义（P〉0．05）。而对白色念珠芮抑制作用各pH值纳米羟基磷灰石组不及氧化锌丁香油组（P〈0．05）,各pH值纳米羟基磷灰石组组间比较,pH10纳米羟基磷灰石组〉pH9纳米羟堆磷灰秆组〉pH8纳米羟基磷灰石组（P〈0．05）。结果表明,感染根管模型中,纳米羟基磷灰石根充糊剂对粪肠球菌的抑制作用好于氧化锌丁香油（P〈0．05）,而对白色念珠菌的抑制作用不及氧化锌丁香油（P〈0．05）。pH=10纳米胫基磷灰石复合根充糊剂的抑菌作用最佳。     

Enhanced photocatalytic activity of TiO2/UiO-67 under visible-light for aflatoxin B1 degradation

TiO₂ has great potential in photocatalytic degradation of organic pollutants, but poor visible light response and low separation efficiency of photogenerated electron–hole pairs limit its wide applications. In this study, we have successfully prepared TiO₂/UiO-67 photocatalyst through an in situ solvothermal method. The degradation rate of aflatoxin B1 (AFB1) is 98.9% in only 80 min, which is superior to the commercial P25, commercial TiO₂ and most of reported photocatalysts under visible light irradiation. In addition, the TiO₂/UiO-67 photocatalyst showed excellent recyclability. We demonstrated that the enhanced photocatalytic mechanism was owing to the heterojunction between TiO₂ and UiO-67, which enhanced effectively the separation photogenerated charge carriers and visible light response. The free radical trapping tests demonstrated that superoxide radicals (˙O₂⁻), holes (h⁺) and hydroxyl radicals (˙OH) were the main active species and then oxidized AFB1 to some small molecules.

Enhanced photocatalytic activity of TiO₂/UiO-67 under visible-light for aflatoxin B1 degradation.     

Density functional theory calculations for evaluation of phosphorene as a potential anode material for magnesium batteries

We have systematically investigated black phosphorus and its derivative – a novel 2D nanomaterial, phosphorene – as an anode material for magnesium-ion batteries. We first performed Density Functional Theory (DFT) simulations to calculate the Mg adsorption energy, specific capacity, and diffusion barriers on monolayer phosphorene. Using these results, we evaluated the main trends in binding energy and voltage as a function of Mg concentration. Our studies revealed the following findings: (1) Mg bonds strongly with the phosphorus atoms and exists in the cationic state; (2) Mg diffusion on phosphorene is fast and anisotropic with an energy barrier of only 0.09 eV along the zigzag direction; (3) the theoretical specific capacity is 865 mA h g⁻¹ with an average voltage of 0.833 V (vs. Mg/Mg²⁺), ideal for use as an anode. Given these results, we conclude that phosphorene is a very promising anode material for Mg-ion batteries. We then expand our simulations to the case of bulk black phosphorus, where we again find favorable binding energies. We also find that bulk black phosphorous must overcome a structural stress of 0.062 eV per atom due to a volumetric expansion of 33% during magnesiation. We found that the decrease in particle size is good to increase its specific capacity.

Phosphorene adsorbs Mg to form a stable product MgP₂, delivering a theoretical specific capacity of 865 mA h g⁻¹.     

Enhanced photocatalytic activity of a B12-based catalyst co-photosensitized by TiO2 and Ru(ii) towards dechlorination

A novel hybrid photocatalyst denoted as B₁₂–TiO₂–Ru(ii) was prepared by co-immobilizing a B₁₂ derivative and trisbipyridine ruthenium (Ru(bpy)₃²⁺) on the surface of a mesoporous anatase TiO₂ microspheres and was characterized by DRS, XRD, SEM and BET et al. By using the hybrid photocatalyst, DDT was completely didechlorinated and a small part of tridechlorinated product was also detected in the presence of TEOA only after 30 min of visible light irradiation. Under simulated sunlight, the hybrid exhibited a significantly enhanced photocatalytic activity for dechlorination compared with B₁₂–TiO₂ under the same condition or itself under visible light irradiation due to the additivity in the contribution of UV and visible part of the sunlight to the electron transfer. In addition, this hybrid catalyst can be easily reused without loss of catalytic efficiency. This is the first report on a B₁₂-based photocatalyst co-sensitized by two photosensitizers with wide spectral response.

The additivity of the contribution of the UV and visible parts of sunlight to electron transfer was confirmed in the B₁₂–TiO₂–Ru(ii) photocatalytic system.     

Origin of the enhanced photocatalytic activity of (Ni,Se, and B) mono- and co-doped anatase TiO2 materials under visible light: a hybrid DFT study

The characteristic properties of TiO₂ (anatase) make doping necessary to enhance its photocatalytic activity. Herein, a density functional theory (DFT) study using the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional was performed to precisely investigate the effect of mono- and co-doping (Ni, Se and B) on the structural, electronic and optical properties of anatase TiO₂. Notably, the origin of the enhanced photocatalytic activity of the modified systems was determined. The response to visible light was enhanced for all the mono- and co-doped materials except for B_int, and the highest absorption coefficient was observed for Se⁴⁺ mono-doping and Se/B_int+sub and Ni/B_sub co-doping. The decrease in bandgap is associated with a red shift in the absorption edges with the smallest bandgap calculated for Ni/B_sub (2.49 eV). Additionally, the Ni, Se⁴⁺ and Se²⁻ mono-doped systems and Ni/Se⁴⁺ co-doped systems are proposed as promising photocatalysts for water splitting applications and further experimental validation. Moreover, the Ni/B_int+sub and Se/B_int+sub co-doped materials can also be valuable photocatalysts for other energy applications due to their enhanced visible light activity and the prolonged lifetime of their produced charge carriers.

Hybrid DFT calculations demonstrate that Ni, Se⁴⁺ and Se²⁻ mono-doped and Ni/Se⁴⁺ co-doped TiO₂ are potential photocatalysts for water splitting and hydrogen production.     

Sol–gel synthesis and solar photocatalytic activity of Ca-alloyed ZnO nanoparticles elaborated using different precursors

Ca-alloyed ZnO nanoparticles elaborated using different calcium precursors (CaSO₄, CaCl₂, Ca(NO₃)₂ and CaCO₃) at different [Ca]/[Zn] ratios (0, 1, 5, 10, 15 and 20%) have been prepared by a sol–gel method followed by supercritical drying and annealing at 300 °C. The synthesized samples have been characterized by a number of techniques including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), Raman Spectroscopy and Electron Paramagnetic Resonance (EPR). SEM and TEM images reveal that the nanoparticles have a quasi-spherical shape with a grain size between 20 and 40 nm. The EDS results on chemical elementary compositions show that the Ca-alloyed ZnO with a CaCO₃ precursor and [Ca]/[Zn] ratios of 5 and 10% are quasi-stoichiometric. The XRD results indicate that all the elaborated nanoparticles have a hexagonal wurtzite structure. Using Raman Spectroscopy a supplementary vibrational mode is detected in the case of CaSO₄, CaCO₃ and Ca(NO₃)₂ precursors. The intrinsic defect centers and defect number have been studied using EPR. Two intrinsic defects with different g factors are identified by EPR for which the spectral intensities change with calcium precursors. Furthermore, EPR reveals a correlation between the defect number and photocatalytic efficiency. The photocatalytic efficiency of the nanoparticles elaborated with different precursors and compositions has been studied for the solar photocatalytic degradation of pyrimethanil, using a solar simulator. The results show that the nanoparticles of Ca-alloyed ZnO elaborated with a CaCO₃ precursor give promising results and enhance the photocatalytic efficiency in the solar field.

Schematic representation of core–shell intrinsic defects in Zn_1−xCa_xO nanoparticles observed by EPR spectroscopy.     

Electronic properties of the coronene series from thermally-assisted-occupation density functional theory

To fully utilize the great potential of graphene in electronics, a comprehensive understanding of the electronic properties of finite-size graphene flakes is essential. While the coronene series with n fused benzene rings at each side (designated as n-coronenes) are possible structures for opening a band gap in graphene, their electronic properties are not yet fully understood. Nevertheless, because of their radical character, it remains very difficult to reliably predict the electronic properties of the larger n-coronenes with conventional computational approaches. In order to circumvent this, the various electronic properties of n-coronenes (n = 2–11) are investigated using thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai, J. Chem. Phys., 2012, 136, 154104], a very efficient electronic structure method for studying nanoscale systems with strong static correlation effects. The ground states of the larger n-coronenes are shown to be polyradical singlets, where the active orbitals are mainly localized at the zigzag edges.

To fully utilize the great potential of graphene in electronics, a comprehensive understanding of the electronic properties of finite-size graphene flakes is essential.     

Electronic and optical properties of Janus ZrSSe by density functional theory

In the present work, we investigate systematically the electronic and optical properties of Janus ZrSSe using first-principles calculations. Our calculations demonstrate that the Janus ZrSSe monolayer is an indirect semiconductor at equilibrium. The band gap of the Janus ZrSSe is 1.341 eV using the Heyd–Scuseria–Ernzerhof hybrid functional, larger than the band gap of ZrSe₂ monolayer and smaller than that of ZrS₂ monolayer. Based on the analysis of the band edge alignment, we confirm that the Janus ZrSSe monolayer possesses photocatalytic activities that can be used in water splitting applications. While strain engineering plays an important role in modulating the electronic properties and optical characteristics of the Janus ZrSSe monolayer, the influence of the external electric field on these properties is negligible. The biaxial strain, ε_b, has significantly changed the band of the Janus ZrSSe monolayer, and particularly, the semiconductor–metal phase transition which occurred at ε_b = 7%. The Janus ZrSSe monolayer can absorb light in both visible and ultraviolet regions. Also, the biaxial strain has shifted the first optical gap of the Janus ZrSSe monolayer. Our findings provide additional information for the prospect of applying the Janus ZrSSe monolayer in nanoelectronic devices, especially in water splitting technology.

In the present work, we investigate systematically the electronic and optical properties of Janus ZrSSe using first-principles calculations.     

Oxygen reduction reaction on Pt-skin Pt3V(111) fuel cell cathode: a density functional theory study

Pt-non-precious transition metals (Pt-NPTMs) alloy electrocatalysts have gained considerable attention to develop cheaper and efficient electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this report, density functional theory (DFT) has been applied to study the catalytic activity of Pt-skin Pt₃V(111) electrocatalyst for ORR in PEMFCs. The results revealed that the ORR intermediates (O, OH and OOH) have lower binding energies on Pt-skin Pt₃V(111) compared to pure Pt(111) surface. The ORR on Pt-skin Pt₃V(111) surface proceed via OOH dissociation with an activation energy of 0.33 eV. The formation of OH is found to be the rate determining step with an activation energy of 0.64 eV, which is even lower than in pure Pt(111) surface (0.72 eV). This indicates a better performance of Pt-skin Pt₃V(111) for ORR compared to pure Pt(111) surface. Moreover, the DFT results revealed that the negative formation energy of the Pt₃V alloy and the positive dissolution potential shift of the surface Pt atoms revealed the better stability of Pt-skin Pt₃V(111) surface over pristine Pt(111) surface. Due to the improved activity and better stability, the new Pt₃V alloy electrocatalyst is very promising for the development of low-cost and efficient PEMFCs.

Pt-non-precious transition metals (Pt-NPTMs) alloy electrocatalysts have gained considerable attention to develop cheaper and efficient electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs).     

Complexation and bonding studies on [Ru(NO)(H2O)5]3+ with nitrate ions by using density functional theory calculation

Complexation reactions of ruthenium–nitrosyl complexes in HNO₃ solution were investigated by density functional theory (DFT) calculations in order to predict the stability of Ru species in high-level radioactive liquid waste (HLLW) solution. The equilibrium structure of [Ru(NO)(NO₃)₃(H₂O)₂] obtained by DFT calculations reproduced the experimental Ru–ligand bond lengths and IR frequencies reported previously. Comparison of the Gibbs energies among the geometrical isomers for [Ru(NO)(NO₃)_x(H₂O)_5−x]^(3−x)+/− revealed that the complexation reactions of the ruthenium–nitrosyl complexes with NO₃⁻ proceed via the NO₃⁻ coordination to the equatorial plane toward the Ru–NO axis. We also estimated Gibbs energy differences on the stepwise complexation reactions to succeed in reproducing the fraction of Ru–NO species in 6 M HNO₃ solution, such as in HLLW, by considering the association energy between the Ru–NO species and the substituting ligands. Electron density analyses of the complexes indicated that the strength of the Ru–ligand coordination bonds depends on the stability of the Ru species and the Ru complex without NO₃⁻ at the axial position is more stable than that with NO₃⁻, which might be attributed to the difference in the trans influence between H₂O and NO₃⁻. Finally, we demonstrated the complexation kinetics in the reactions x = 1 → x = 2. The present study is expected to enable us to model the precise complexation reactions of platinum-group metals in HNO₃ solution.

Density functional study on the complexation of [Ru(NO)(H₂O)₅]³⁺ with NO₃⁻ ions reproduced the stabilities of the geometrical isomers and the stepwise substitution reactivities by combining the association energy with the leaving/entering ligands.     

双层探测器光谱CT碘密度值对不同功能状态下肾上腺的评估

目的 探讨双层探测器光谱CT碘密度定量对肾上腺不同功能状态的评估价值.方法 2018年6月～2020年8月间于我院完成肾上腺光谱CT增强扫描的检查者中,按照不同的肾上腺功能状态收集病例,分为三组:感染性休克(双侧肾上腺肿大)26例(A组);肾上腺增生(双侧或左侧)14例(B组);右侧功能性肾上腺皮质醇腺瘤(左侧肾上腺反...     

Adsorption and dissociation behavior of H2 on PuH2 (100), (110) and (111) surfaces: a density functional theory+U study

The density functional theory (DFT) and DFT plus correction for on-site Coulomb interaction (DFT+U) method were performed to investigate the adsorption and dissociation of H₂ on PuH₂ (100), (110) and (111) surfaces. Overall, the H₂ molecule can be adsorbed on the PuH₂ surface without spontaneous dissociation. The calculated H–H bond lengths (R_H–H) are all elongated to different degrees, and the R_H–H at different adsorption sites is about 0.84–4.21% longer than in the gas phase. We found that the dissociation of H₂ on the (110) surface is a spontaneous exothermic process, and a total energy of 0.60 eV is released in the whole process. The smaller barriers corroborate that the migration of an H atom on the PuH₂ surface is possible, and even spontaneous diffusion may occur. The spontaneous migration of a hydrogen atom adsorbed on the (110) surface from the surface to the interior promotes the conversion of PuH₂ to PuH₃, which may be the fundamental driving force of hydrogenation corrosion. Our results provide useful information to explain the mechanism of hydrogenation corrosion on the PuH₂ surface.

The density functional theory (DFT) and DFT plus correction for on-site Coulomb interaction (DFT+U) method were performed to investigate the adsorption and dissociation of H₂ on PuH₂ (100), (110) and (111) surfaces.     

Adsorption of CO2 on the ω-Fe (0001) surface: insights from density functional theory

The stabilization of a hexagonal phase known as the ω-phase in steel has recently been identified. The presence of C in steel samples is found to be helping the formation of this otherwise meta stable phase. This indicates that the probability of degradation of the surface is high in steel samples containing the ω-phase, through surface adsorption. Here we calculate the adsorption process of CO₂ on the ω-Fe(0001) surface, for different sites and find that it strongly adsorbs horizontally with a bent configuration. The adsorption is characterized by significant charge transfer from the surface Fe atoms to the CO₂ molecule, and structural modification of the molecule is occurring. The density of states calculations indicate that hybridization and subsequent charge transfer is probable between the d orbitals of Fe and p orbitals of CO₂, resulting in strong chemisorption, that further leads to spontaneous dissociation of the molecule.

Chemisorption of CO₂ on the ω-Fe (0001) surface for the most stable adsorption site.