A Novel Approach to Carbon Monoxide Removal Using Transition Metal-Doped Boron Nitride Nanosensors for Environmental Sustainability

Fatemeh Mollaamin ^*

1. Department of Biomedical Engineering, Faculty of Engineering and Architecture, Kastamonu University, Kastamonu, Turkey

* Correspondence: Fatemeh Mollaamin

Academic Editor: Junkuo Gao

Received: November 12, 2024 | Accepted: March 27, 2025 | Published: April 02, 2025

Journal of Energy and Power Technology 2025, Volume 7, Issue 2, doi:10.21926/jept.2502006

Recommended citation: Mollaamin F. A Novel Approach to Carbon Monoxide Removal Using Transition Metal-Doped Boron Nitride Nanosensors for Environmental Sustainability. Journal of Energy and Power Technology 2025; 7(2): 006; doi:10.21926/jept.2502006.

© 2025 by the authors. This is an open access article distributed under the conditions of the Creative Commons by Attribution License, which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is correctly cited.

1. Introduction

The privileged attributes of boron nitrides, mainly structural and electronic, have made them proper for pollutant adsorption and semiconducting properties [1,2,3,4]. Boron nitride nanomaterials usually exhibit semi-leading behavior, which is considered an appropriate alternative to carbon nanotubes. The unique properties of boron and nitrogen atoms make boron nitride an interesting subject of numerous studies [5,6,7].

In recent years, different investigations on the adsorption of chemical contaminants and applying various boron nitride nanostructures as adsorbents for water purification have been studied [8,9,10].

Various physical shapes of boron nitride (BN)-based nano adsorbents such as nanoparticles, fullerenes, nanotubes, nanofibers, nanoribbons, nanosheets, nanomeshes, nanoflowers, and hollow spheres have been broadly considered possible adsorbents owing to their exceptional characteristics such as large surface area, structural variability, great chemical/mechanical strength, abundant structural defects, high reactive sites, and functional groups [11,12].

Carbon monoxide (CO), carbon dioxide and methane are environmental problems. CO is a toxic gas that, at standard conditions, is tasteless, odorless, and colorless. It comes primarily from incomplete combustion of carbon-containing fuels. It is not irritating, and it is an asphyxiant. At high levels, it is deadly. The investigation of the adsorption of carbon monoxide on palladium and transition metals is an attractive research topic [13].

The researchers have applied Density functional theory for the computation of geometry optimizations, binding and adsorption energies, and electronic properties of CO molecule adsorption on pristine and group 8B transition metal (TM)–doped boron nitride nanosheets (BNNS). They exhibited that the TM atom displays strong binding with B and N vacancy BNNSs with energy gaps of TM–doped BNNS smaller than that of pristine BNNS. The CO tends to attach via its C and O atoms to TM–doped BNNSs with more considerable adsorption energy and smaller adsorption distance than that of pristine BNNS [14].

The interactions between carbon monoxide gas and boron nitride nanocage were investigated using two DFT functionals (B3LYP and B97D) and a 6-31G(d) basis set. The computational results indicated the capability of B₁₂N₁₂ as a sensor for potential applications in the detection of CO under an external electric field [15,16].

2. Materials and Methods

This research article wants to remove toxic gas molecules, including CO, from the air through an eco-friendly approach by using (Ti, V, Cr, Co, Cu, Zn)-doped B₅N₁₀_NC (Figure 1).

Figure 1 Application of X–B₄N₁₀_NC towards adsorption of gas molecules of CO and formation of complexes: "CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, CO@Zn–B₄N₁₀_NC" complexes.

Boron nitride nanocage has been designed owing to doping atoms of titanium, vanadium, chromium, cobalt, copper, and zinc which can increase the gas sensing potential of BN-nanocage.

Figure 1 has declared the status of CO adsorption on the X–B₄N₁₀_NC surface which towards formation of complexes containing CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, CO@Zn–B₄N₁₀_NC by computational chemistry.

The charge distribution of the mentioned complexes is calculated due to the Bader charge analysis [17]. The trapping of CO molecules by X–B₄N₁₀_NC (X = Ti, V, Cr, Co, Cu, Zn) was successfully incorporated due to binding formation consisting of C → Ti, C → V, C → Cr, C → Co, C → Cu, C → Zn (Figure 1).

Development of the applied Density Functional Theory (DFT) methodology only became notable after W. Kohn and L. J. Sham released their reputable series of equations which are introduced as Kohn-Sham (KS) equations [18,19,20,21,22,23]. So, one starts with a reference model of M with non-interacting electrons related to the external potential $v_{s}$ and with Hamiltonian [24,25,26,27,28,29,30,31]:

By representing the single particle orbitals $\psi_{i}$ all electronic densities physically acceptable for the system of "non-interacting" electrons are written in the equation (2):

Finally, the total energy could be measured by the KS method due to the equation (3):

In this article, the rigid PES using DFT calculations has been computed applying Gaussian 16 revision C.01 software [32]. The input Z-matrix for adsorption of CO molecules in air by the X–B₄N₁₀_NC has been designed with GaussView 6.1 [33] using 6–311+G (d,p), EPR–3, LANL2DZ basis set.

3. Results and Discussion

Electric field gradient (EFG) at the citation of the nucleus in CO is allocated by the valence electrons twisted in the attachment with close nuclei of X–B₄N₁₀_NC (X = Ti, V, Cr, Co, Cu, Zn) (Figure 2). So, "the nuclear quadrupole resonance (NQR) frequency" can be measured for CO@X–B₄N₁₀_NC complexes using Gaussian 16 revision C.01 software [32] (Table 1 & Table 2).

Figure 2 Carbon monoxide adsorbed on the surface of X–B₄N₁₀_NC (X = Ti, V, Cr, Co, Cu, Zn) towards the formation of a) CO@Ti–B₄N₁₀_NC, b) CO@V–B₄N₁₀_NC, c) CO@Cr–B₄N₁₀_NC, d) CO@Co–B₄N₁₀_NC, e) CO@Cu–B₄N₁₀_NC and f) CO@Zn–B₄N₁₀_NC.

Table 1 The electric potential (a.u.) and Bader charge (e) through NQR calculation for CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC complexes.

Table 2 The electric potential (a.u.) and Bader charge (e) through NQR calculation for CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, and CO@Zn–B₄N₁₀_NC complexes.

The NQR method is related to the multipole expansion in Cartesian coordinates as the equation (4) [34,35]:

After that, a simplification on the equation (4), there are only the second derivatives related to the identical variable for the potential energy [34,35]:

There are two parameters which must be gotten from NQR experiments: the quadrupole coupling constant, $\chi$, and asymmetry parameter of the EFG tensor η:

η

where $q_{ii}$ are ingredients of the EFG tensor at the quadrupole nucleus determined in the EFG principal axes system, $Q$ is the nuclear quadrupole moment, $e$ is the proton charge and $h$ is the Planck's constant [36,37].

In this research work, the electric potential as the quantity of work energy through carrying over the electric charge from one position to another position in the essence of electric field has been evaluated for "CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, and CO@Zn–B₄N₁₀_NC" complexes (Table 1 & Table 2).

Doping atoms of Ti(15), V(15), Cr(15), Co(15), Cu(15), Zn(15) on the B₅N₁₀_NC have shown the most potential for accepting the electron from the electron donor of C(1) and O(2) in CO adsorbed on the X–B₄N₁₀_NC (Figure 3).

Figure 3 "Electric potential (a.u.) versus Bader charge (coulomb)" for a) CO@Ti–B₄N₁₀_NC, b) CO@V–B₄N₁₀_NC, c) CO@Cr–B₄N₁₀_NC, d) CO@Co–B₄N₁₀_NC, e) CO@Cu–B₄N₁₀_NC, and f) CO@Zn–B₄N₁₀_NC complexes.

In Figure 3(a) and (b), it was observed the behavior of CO adsorption on the Ti–B₄N₁₀_NC and CO@V–B₄N₁₀_NC, with the analogous high sensitivity based on the relation coefficient of R² = 0.986 and R² = 0.9323, respectively. Adsorption of CO on the Cr–B₄N₁₀_NC, Co–B₄N₁₀_NC and Cu–B₄N₁₀_NC in Figure 3(c), (d) and (e), respectively, has illustrated the highest sensing of R² = 0.9666, and R² = 0.9679 (both Co–B₄N₁₀_NC and Cu–B₄N₁₀_NC). However, Figure 3(f) has resulted that CO@Zn–B₄N₁₀_NC has a lower potential than other nanocage surfaces for CO removal from air (R² = 0.687). The adsorbents of chromium with 0.5883, zinc with 0.6853, vanadium with 0.6893, and titanium with 0.7499 coulomb, respectively, have presented the most tendency for being the electron acceptors. The uptake of gas molecules has been known to be associated with X–B₄N₁₀_NC, indicating that the adsorbed CO molecules in the X–X-doped nanocage can be internalized through a different pathway from pristine nanocage.

The chemical shielding resulted from NMR [38] spectroscopy including isotropic (σ_iso) and anisotropic (σ_aniso) for gas molecules trapped in the X–B₄N₁₀_NC towards the formation of CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, and CO@Zn–B₄N₁₀_NC complexes have been computed by Gaussian 16 revision C.01 program package [30] and been shown in Table 3 & Table 4.

Table 3 NMR tensors (ppm) for selected atoms of CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, and CO@Co–B₄N₁₀_NC complexes.

Table 4 NMR tensors (ppm) for selected atoms of CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, and CO@Zn–B₄N₁₀_NC complexes.

NMR parameter (ppm) has reported the notable amounts for CO which were adsorbed on the X–B₄N₁₀_NC (Table 3 & Table 4). The increase in the NMR anisotropy spans for C(1) and O(2) atoms of CO adsorption on the X–B₄N₁₀_NC. Notably, doping of Ti, V, Cr, Co, Cu, and Zn on B₄N₁₀_NC might promote the strength of nanocage. The adsorption of CO can present spin polarization on the X–B₄N₁₀_NC which indicates that these nano-surfaces may be employed as magnetic scavenging surfaces as a gas detector.

Figure 4(a-f) indicates the similar orientation of NMR parameter (ppm) for boron and nitrogen; however, a remarkable deviation is observed from doping atoms of Ti(15), V(15), Cr(15), Co(15), Cu(15), Zn(15) through interaction with C(1) and O(2) of CO during adsorbing on the B₅N₁₀_NC.

Figure 4 NMR tensors (ppm) for a) CO@Ti–B₄N₁₀_NC, b) CO@V–B₄N₁₀_NC, c) CO@Cr–B₄N₁₀_NC, d) CO@Co–B₄N₁₀_NC, e) CO@Cu–B₄N₁₀_NC, and f) CO@Zn–B₄N₁₀_NC complexes using CAM–B3LYP–D3/6-311+G (d,p), LANL2DZ.

In Figure 4(a-f), gas molecules of CO in the complexes of CO@Ti–B₄N₁₀_NC (Figure 4a), CO@V–B₄N₁₀_NC (Figure 4b), CO@Cr–B₄N₁₀_NC (Figure 4c), CO@Co–B₄N₁₀_NC (Figure 4d), CO@Cu–B₄N₁₀_NC (Figure 4e), and CO@Zn–B₄N₁₀_NC (Figure 4f) exhibit the alteration in the NMR parameter among gas grabbing.

The IR calculations have been done for the adsorption of CO molecules by X–B₄N₁₀_NC during toxic gas sensing in air. Therefore, it has been simulated the several clusters containing CO@Ti–B₄N₁₀_NC (Figure 5a), CO@V–B₄N₁₀_NC (Figure 5b), CO@Cr–B₄N₁₀_NC (Figure 5c), CO@Co–B₄N₁₀_NC (Figure 5d), CO@Cu–B₄N₁₀_NC (Figure 5e) and CO@Zn–B₄N₁₀_NC (Figure 5f) complexes.

Figure 5 IR spectra for a) CO@Ti–B₄N₁₀_NC, b) CO@V–B₄N₁₀_NC, c) CO@Cr–B₄N₁₀_NC, d) CO@Co–B₄N₁₀_NC, e) CO@Cu–B₄N₁₀_NC, and f) CO@Zn–B₄N₁₀_NC complexes.

The graph of Figure 5(a) has been observed in the frequency range between 100–1100 cm^-1 for CO@Ti–B₄N₁₀_NC with sharp peaks around 202.69, 606.23 and 858.53 cm^-1. Figure 5(b) has shown the frequency range between 100–1100 cm^-1 for CO@V–B₄N₁₀_NC with two sharp peaks around 369.36, 422.65 and 603.26 cm^-1. Figure 5(c) has indicated the fluctuation of frequency between 100–1100 cm^-1 for CO@Cr–B₄N₁₀_NC with several sharp peaks around 328.93, 433.18 and 554.91 cm^-1. Figure 5(d) has shown the fluctuation of frequency between 100–1100 cm^-1 for CO@Co–B₄N₁₀_NC with sharp peaks around 180.91, 211.68, 370.94, 403.62, 545.15, and 642.16 cm^-1. Moreover, it has been observed that the frequency between 200–1100 for CO@Cu–B₄N₁₀_NC with sharp peaks around 357.09, 581.27 and 673.35 cm^-1 (Figure 5e). Besides, Figure 5(f) has exhibited the frequency between 200–1100 for CO@Zn–B₄N₁₀_NC with sharp peaks around 264.84, 563.65 and 769.01cm^-1.

Thermodynamic specifications have been concluded that X–B₄N₁₀_NC due to adsorption of CO might be more efficient sensors for detecting and removing the gas molecules from the polluted air (Table 5).

Table 5 The thermodynamic characters of CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, and CO@Zn–B₄N₁₀_NC complexes using CAM–B3LYP–D3/6–311+G (d,p), LANL2DZ calculation.

It has been indicated that for a given number of carbon donor sites in CO, the stabilities of complexes owing to doping atoms of Ti, V, Cr, Co, Cu, Zn can be considered as: CO@Cu–B₄N₁₀_NC >> CO@Co–B₄N₁₀_NC > CO@Cr–B₄N₁₀_NC > CO@V–B₄N₁₀_NC > CO@Zn–B₄N₁₀_NC > CO@Ti–B₄N₁₀_NC (Table 5).

The adsorption process of CO gas molecules on the X–B₄N₁₀_NC is affirmed by the $\Delta \mathrm{G°}_{\mathrm{ads}}$ quantities:

Figure 6 has shown that the key role of doped atoms of Ti, V, Cr, Co, Cu, Zn during interaction between the adsorbates of CO gas molecules as the electron donors and the adsorbent of Ti–B₄N₁₀_NC, V–B₄N₁₀_NC, Cr–B₄N₁₀_NC, Co–B₄N₁₀_NC, Cu–B₄N₁₀_NC, and Zn–B₄N₁₀_NC as electron acceptors. Therefore, the selectivity of atom-doped on boron nitride nanocage (gas sensor) for gas molecules adsorption can be resulted as: Cu >> Co > Cr > V > Zn > Ti (Table 5 & Figure 6).

Figure 6 The Gibbs free energy ($\Delta \mathrm{G°}_{\mathrm{ads}}$) versus dipole moment (Debye) for CO@Ti–B₄N₁₀_NC, CO@V–B₄N₁₀_NC, CO@Cr–B₄N₁₀_NC, CO@Co–B₄N₁₀_NC, CO@Cu–B₄N₁₀_NC, and CO@Zn–B₄N₁₀_NC complexes.

A strong donor–acceptor interaction between CO and TM–doped B₄N₁₀_NC has been probed. The orbital distribution analysis shows that electrons are delocalized around the adsorption site. Energy gaps and density of states of TM–doped B₄N₁₀_NC are significantly changed after CO adsorption, corresponding to the significant change of electrical conductivity of TM–doped BNNSs. In conclusion, TM–doped B₄N₁₀_NC are strongly reactive and sensitive to CO molecule and therefore it can be used as adsorption and sensing nanomaterials.

4. Conclusion

Various industries utilize gas sensors for environmental monitoring. The advantage of the gas sensors is limited due to the low sensitivity of sensing nanomaterial produced from pristine structures. The functionalization of pristine nanomaterial leads to enhanced adsorption reactivity and improvement of sensitivity. Many theoretical studies suggest that the functionalization by impurity atom doping in nanomaterial can enhance chemical reactivity. This research has investigated the doping of Ti, V, Cr, Co, Cu, and Zn transition metals in the boron nitride nanocage (X–B₄N₁₀_NC) for enhancing toxic gas sensing of these nanomaterials in air pollution removal. Therefore, CO gas molecule separation involving X–B₄N₁₀_NC has been experimentally investigated based on electrostatic interactions between the gas molecules and X–B₄N₁₀_NC. The electromagnetic and thermodynamic properties of X–B₄N₁₀_NC complexes were computed using the DFT method. The data has demonstrated that the chosen gas molecules adsorbed on the X–B₄N₁₀_NC are relatively stable, with the most stable adsorption site being in the center of the X–B₄N₁₀_NC system. The selectivity of atom-doped on boron nitride nanocages (gas sensor) for gas molecule adsorption can be as follows: CO@Cu–B₄N₁₀_NC > CO@Co–B₄N₁₀_NC > CO@Cr–B₄N₁₀_NC > CO@V–B₄N₁₀_NC > CO@Zn–B₄N₁₀_NC > CO@Ti–B₄N₁₀_NC, respectively.

Acknowledgments

The author is grateful to Kastamonu University for completing this paper and its research.

Author Contributions

Fatemeh Mollaamin (F.M.): Conceptualization, writing – original draft, formal analysis, writing – review and editing. The author has read and approved the published version of the manuscript.

Competing Interests

The authors have declared that no competing interests exist. The author states the topic selection, innovations and methods, etc. of this study are not duplicated in authors’ published articles.