Next Article in Journal
Hierarchical Manganese-Doped Nickel–Cobalt Oxide Electrodes with Graphene for Use as High-Energy-Density Supercapacitors
Previous Article in Journal
The Effect of Low-Temperature Plasma Treatment on the Adhesive Bonding Performance of CF/PEKK Surfaces
Previous Article in Special Issue
Drying and Film Formation Processes of Graphene Oxide Suspension on Nonwoven Fibrous Membranes with Varying Wettability
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Surfaces
Volume 8
Issue 3
10.3390/surfaces8030042
surfaces-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Hydrophobic Boron Nitride Nanoflower Coatings on Mild Steel Surfaces

by
Aamir Nadeem
1,†,
Muhammad Faheem Maqsood
2,3,*,†,
Mohsin Ali Raza
1,*,
Syed Muhammad Zain Mehdi
3,4 and
Shahbaz Ahmad
2
1
Institute of Metallurgy & Materials Engineering, Faculty of Chemical & Materials Engineering, University of the Punjab, Lahore 54590, Pakistan
2
Materials Research Center (MRC), College of Arts and Science, American University of Sharjah, Sharjah 26666, United Arab Emirates
3
Hybrid Materials Centre (HMC), Department of Nanotechnology & Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
4
School of Chemical, Biological and Battery Engineering, Gachon University, Seongnam 13120, Republic of Korea
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Surfaces 2025, 8(3), 42; https://doi.org/10.3390/surfaces8030042
Submission received: 23 April 2025 / Revised: 22 June 2025 / Accepted: 22 June 2025 / Published: 25 June 2025
(This article belongs to the Special Issue Surface Engineering of Thin Films)
Browse Figures
Versions Notes

Abstract

Growing demand for chemically resistant, thermally stable, and anti-icing coatings has intensified interest in boron nitride (BN)-based materials and surface coatings. In this study, BN coatings were developed on mild steel (MS) via chemical vapour deposition (CVD) at 1200 °C for 15, 30, and 60 min, and their structural, surface, and water-repellent characteristics were evaluated. X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy confirmed the successful formation of BN, while water contact angle measurements indicated high hydrophobicity, demonstrating excellent barrier properties. Scanning electron microscopy (SEM) revealed morphological evolution from flower- and needle-like BN structures in the sample placed in the CVD furnace for 15 min to dense, coral-like, and tubular networks in the samples placed for 30 and 60 min. These findings highlight that BN coatings, particularly the one obtained after 30 min of deposition, have a high hydrophobic character following the Cassie–Baxter model and can be used for corrosion resistance and anti-icing on MS, making them ideal for industrial applications requiring long-lasting protection.

Graphical Abstract

1. Introduction

Metallic surface corrosion poses a critical challenge across industries (manufacturing, building, aerospace, etc.), leading to structural degradation, safety risks, and significant economic losses [1,2,3]. One of the most common metals, mild steel (MS), which is widely used in construction, automotive, and marine applications, is susceptible to corrosion due to its chemical reactivity and exposure to aggressive environments like chlorides and moisture [4,5,6,7,8,9,10]. The most common way to protect MS from corrosion is to use protective coatings; however, traditional coatings, including organic, metallic, and ceramic-based layers, have demonstrated limited effectiveness under prolonged exposure to harsh conditions [11,12,13,14,15,16,17,18]. Therefore, advanced materials must be developed to protect MS or any metal for longer periods [19,20,21].
With the unique arrangements of Boron (B) and Nitrogen (N) in the ratio of 1:1 in the overall structure of boron nitride (BN) [22,23], it has emerged as a promising material for corrosion protection [24,25,26,27,28,29]. BN is an inorganic ceramic material that, with its different types and dimensions (0D = fullerene-like BN, 1D = BN nanotubes, 2D = BN nanosheets, and 3D = cubic BN particles), can offer exceptional chemical stability, electrical insulation, hydrophobicity, and impermeability to ions and gases [30,31,32,33,34]. In particular, boron nitride nanotubes (BNNT) and boron nitride nanosheets (BNNS) are potential candidates for advancing the development of robust anticorrosion coatings for metallic surfaces that are exposed to strongly corrosive and high-temperature environments [35,36,37,38]. Unlike graphene, which can promote inter-layer galvanic corrosion due to its electrical conductivity, hexagonal BN (h-BN) provides long-term stability without compromising the substrate’s structural integrity due to its wide band gap and chemical stability even in harsh conditions [39,40,41,42].
Recent advancements have demonstrated the potential of BNNS-based coatings for MS substrates. Our group had also reported BN-based coatings directly deposited on MS following a novel approach based on reaction between ammonia and boron powder in a chemical vapor deposition (CVD) setup [24,43,44]. We noted a significant improvement in corrosion resistance, with the charge transfer resistance (Rct) increasing from 298.8 Ω·cm2 for bare MS to 1996.3 Ω·cm2 for BNNS-coated samples, and a reduction in corrosion current density from 32.00 μA/cm2 to 15.90 μA/cm2 in 3.5 wt.% NaCl solution. Beyond flat nanosheets like BNNS, researchers have increasingly explored BN structures with flower-like morphologies due to their high surface area and enhanced functional performance. For instance, Farhan et al. [45], successfully synthesized polycrystalline BN microflowers via a solvothermal method, forming microneedle-like structures with high surface roughness and a wide bandgap of ~4.35 eV. They further integrated it onto graphite electrodes to produce sensors for the selective and stable electrochemical detection of nicotinamide (vitamin B3), achieving an outstanding detection limit of 330 ppm. Their prepared sensor’s performance, including excellent reproducibility and 93.6% recovery in saliva, highlighted the potential of BN flowers for real-time, non-invasive biomedical diagnostics. In another recent notable study, Liu et al. [46], prepared BN flower-like nanostructures (BNFs) via high-temperature calcination with controlled defect concentrations. The low-defect variant (Vpoor-BNF) showed superior crystallinity and photoelectric properties, leading to a CO2-to-CO conversion rate of 32 μmol g−1 h−1 with 86.9% selectivity, more than double its high-defect counterpart. In parallel, numerous studies have explored the water wettability of BN nanostructures to assess their suitability for coatings in high-temperature and harsh environmental conditions, including anti-icing applications. Pakdel et al. [47] Synthesized BNNS coatings via thermal CVD to demonstrate that they can undergo transition from hydrophilic to superhydrophobic simply by adjusting the growth temperature. They noted that water contact angles (WCA) increased from ~51° to 159°, confirming that surface morphology and roughness strongly influence wettability, aligning with the Cassie–Baxter model. Verma and Rajan [48] revealed that surface roughness rather than atomic defects is the primary factor influencing the wettability and slip behavior of h-BN. They ran simulations and accurately reproduced the experimentally observed WCA of ~66° on pristine h-BN, highlighting the critical role of edge exposure in modulating interfacial properties. In a recent study, Yang et al. [49] demonstrated that the advancing WCA best represents the intrinsic water wettability of h-BN, measured at 79 ± 3°, rather than the static WCA, which is strongly influenced by surface defects and airborne hydrocarbons. Their findings highlight the importance of dynamic contact angle measurements in accurately assessing the wettability of 2D materials like h-BN. These studies identified the tunable wetting properties of BN nanostructures and their potential for use in multifunctional coatings.
The present study is the continuation of our previous work on BN-based coatings. This study is focused on growing different forms of BN on MS substrates using tailored CVD deposition techniques. The special arrangement of MS sample, alumina boat, aluminium shreds and platinum crucible containing boron powder in CVD enabled us to obtain the unique morphologies of BN coatings. These BN coatings (coral, nanotubes, flowers, etc.) were hypothesized to enhance the surface area, create a more effective barrier against corrosive agents and anti-icing with self-cleaning, and contribute to developing next-generation materials for industrial applications.

2. Experimental

2.1. Materials

Boron powder, with a particle size of 1–2 μm and a purity of 99%, was sourced from US Research Nanomaterials, Inc., Houston, USA, Mild steel (MS), aluminum (Al) foil and ammonia gas were procured from a local supplier.

2.2. Coating Procedure

Following our previous research work [24], MS strips, measuring 1 × 2 cm2, were prepared by etching in a 5% HCl solution, followed by sonication and cleaning with acetone and ethanol. For the coating process, 100 mg of boron powder with little shreds of Al foil was placed in a cleaned alumina boat, which was then inserted into the quartz tube of a CVD furnace. The setup for the coating procedure is illustrated in Figure 1, with the MS sample positioned on the alumina boats and a Pt crucible placed in front of it with the same boron powder and Al foil shreds (this Pt crucible also helps to regulate the gases inside the CVD tube, as shown in Figure 1). After that, the quartz tube was sealed and evacuated for 30 min to reduce pressure to 1 bar (0.1 MPa). Ammonia gas (NH3) was introduced at a 200–250 sccm flow rate. Based on optimized experimental conditions, the furnace temperature was gradually increased from room temperature to 1200 °C at a rate of 50 °C per minute. The samples were maintained at 1200 °C for 15–60 min before cooling overnight to room temperature within the sealed quartz tube. Herein, the BN-coated samples for 15, 30, and 60 min will be denoted as BN-15, BN-30, and BN-60, respectively.

2.3. Characterization

The crystal structure of these BN-coated samples was studied using X-ray diffraction (XRD, Malvern Panalytical X’Pert3 diffractometer, Malvern, England). The presence of bonds and their respective movements in the structure are analyzed using Fourier transform infrared attenuated total reflectance (ATR-FTIR, IRSpirit, Shimadzu, Kyoto, Japan). Water contact angles were measured with a drop shape analyzer (DSA, DSA100M, Kruss GmbH, Hamburg, Germany) to study the hydrophobic and hydrophilic characteristics of the coated and neat (bare) MS samples. High magnification images are taken using a scanning electron microscope (SEM, VEGA 3 LMU, TESCAN, Brno, Czech Republic) to study the morphology of these BN-coated samples, where for the element’s detection, we used elemental mapping using an INCAx-act EDS detector from Oxford Instruments (Oxfordshire, England) attached to the SEM.
Electrochemical testing was conducted to evaluate the corrosion protection performance of bare and BN-coated samples using a three-electrode system with a potentiostat/galvanostat (Reference 3000, Gamry Instruments, Warminster, Pennsylvania, USA). The MS sample (and coated samples) served as the working electrode, platinum wire as the counter electrode, and a saturated calomel electrode (SCE) as the reference, and the tests were carried out in 3.5% NaCl solution with a 1 cm2 exposed sample area (insulated by polyester resin except for the test area, and electrical connections were made via soldered Cu wire). After stabilizing the open circuit potential (OCP) for approximately 15 min (±3 mV variation), the potentiodynamic polarization technique was employed with an overpotential range of −0.5 V to 1.5 V (vs. OCP) at a 1 mV/s scan rate. Data analysis (Tafel extrapolation method) was completed using Echem Analyst 6.25 software.

3. Results and Discussion

3.1. XRD and FTIR

XRD analysis of the BN-coated and bare MS samples is presented in Figure 2a. It highlights the progressive growth of BN nanoforms on the MS, increasing deposition time from 15 min to 60 min at 1200 °C. Here, the BN-coated samples (BN-15, BN-30, and BN-60) exhibit prominent (002) reflection at ~26°, which is a characteristic peak of h-BN and is well matched with the COD data sheet (COD# 96-101-0603). We noted no or a very minor shift in the (002) peak for all BN-coated samples with almost similar d-spacing values; BN-15 at 2θ = 26.629° have d-spacing = 0.335 nm, BN-30 at 2θ = 26.365° have d-spacing = 0.338 nm, and BN-15 at 2θ = 26.458° have d-spacing = 0.337 nm, representing a very stable and crystalline structure. Further, FTIR is used to confirm the formation of BN and its relation to the nano form. The FTIR peak in Figure 2b shows that the bare MS lacks significant peaks, while BN-coated samples have distinct peaks at ~1370 cm−1 and ~780 cm−1, corresponding to B–N stretching and B–N–B bending vibrations, respectively [18].

3.2. SEM and EDX Analysis

The SEM images shown in Figure 3 illustrate the morphological evolution of the BN coatings with increasing deposition times. In Figure 3a–c, BN-15 displays partial coverage of the MS substrate with flower-like and needle-like structures, indicating the nucleation phase. Meanwhile, the SEM images of BN-30 in Figure 3d–f show denser coverage of the MS substrate with coral-like and layered formations, reflecting improved growth uniformity. It is similar to the middle phase for the complete flower-like BN growth. Finally, the BN-60 in Figure 3g–i exhibits a fully developed network of flower-like and hollow tubular BN structures, representing the most mature and complete growth. However, as seen in their SEM images, this BN-60 coating is not uniform and fully covered; hence, their water contact angles are expected to be not higher than the BN-15 and BN-30.
EDX analysis confirms the elemental composition of the BN-coated samples, and as shown in Figure 4, the “B” and “N” are found in all BN-coated samples. The ratio of B:N is almost 1:1 in all (BN-15, BN-30, and BN-60) MS-coated samples and confirms the successful stoichiometric formation of BN, critical for achieving the chemical stability and durability of BN-coated MS samples.

3.3. Growth Mechanism

The growth of BN structures on MS during the CVD process is likely to proceed via a surface-mediated, Fe-catalyzed mechanism that is fundamentally similar to the root-growth model observed in carbon nanotubes (CNT) and BNNT synthesis [36,50,51,52,53,54,55,56,57,58]. At the elevated synthesis temperature (1200 °C), B and N precursors, generated from solid B and NH3, are adsorbed onto the Fe-rich surface of the MS substrate. Fe, a known catalyst for nanostructure formation, facilitates the dissociation of N species and promotes the formation of B–N bonds [36,57,59]. These B–N units then condense into stable BN rings, which undergo surface diffusion and merge through a process known as network fusion. This leads to the formation of h-BN domains that expand laterally and vertically, forming flower-, coral-, or sheet-like morphologies depending on precursor availability and deposition time. In early stages (BN-15), incomplete nucleation results in sparse, flower-like and needle-shaped structures. At intermediate stages (BN-30), a more balanced supply of B and N enables the formation of interconnected coral and sheet-like layers. Extended deposition (BN-60) promotes anisotropic growth into vertically aligned tubular BN nanostructures (flowers), similar to BNNTs, which can emerge from the steel surface through a root-growth mode (shown in Figure 1 and Figure 3). This growth is further guided by the catalytic Fe, which supports cleavage of B–B and N–N bonds and helps to form defect-free hexagonal networks [59,60,61]. Additionally, the use of a Pt crucible may have introduced spatial variation in gas flow, leading to uneven precursor distribution and a mixture of morphologies across the substrate. This proposed mechanism aligns with recent molecular dynamics and DFT studies, which reveal that Fe facilitates the surface nucleation and network fusion necessary for BN nanotube and nanosheet growth, even in the absence of metal nanoparticle catalysts [50,62,63,64].

3.4. Water Contact Angle (WCA)

To study the hydrophobic nature of the BN coatings, we measured the WCA as shown in Figure 5. Bare MS shows a moderate WCA of ~92.3°, attributed to its planar surface and metallic nature. The BN-coated samples show significantly higher contact angles than bare MS, representing their hydrophobic nature, which is highly necessary for any corrosion resistance and, to some extent, anti-icing performance, as it reduces direct contact between water and the substrate. BN-15 shows ~127.6°, BN-30 shows ~131.3° and BN-60 shows ~101.6° WCA. Specifically, BN-15 and BN-30 exhibit relatively more WCA due to the needle-like morphology (nanocones, nanotubes, etc.) [65], which traps more air and promotes a Cassie–Baxter wetting state [47,66,67]. Conversely, the flower-like morphology of BN-60 results in less uniform coverage and minimal air entrapment, leading to a Wenzel-type wetting behavior [68,69]. These findings suggest that BN coatings, particularly those with well-defined nanostructures, offer promising potential as protective, hydrophobic layers for corrosion and anti-icing applications on mild steel surfaces.

3.5. Electrochemical Study

The electrochemical study is conducted in a 3.5 wt.% NaCl electrolyte, and the samples were stabilized for almost 15 min before obtaining the potentiodynamic polarization curves. Figure 6 illustrates the potentiodynamic polarization curves, which elucidate the corrosion resistance of the bare and BN-coated MS samples by detailing their polarization behaviour in anodic and cathodic regions. As can be seen from the polarization curves in Figure 6 and Table 1 (using the Tafel extrapolation method) the bare MS displayed the highest corrosion current density (Icorr = 9.45 µA/cm2); in contrast, the BN-coated samples showed significantly reduced Icorr, while BN-30 was found to have the lowest Icorr value (0.974 µA/cm2). Further, the polarization resistance (Rp) data presented in Table 1 (following [70]) complements the findings of Icorr and the corrosion potential (Ecorr) of the bare and BN-coated samples. Due to the very dense, uniform, coral-like BN layer of BN-30, which has a high water contact angle (Figure 5c), it exhibited the highest Rp (25.94 Ω·cm2) and the lowest average corrosion rate (0.445 mph). However, we noticed that the coatings did not strongly influence the anodic branch of the polarization curves; the cathodic current densities were substantially suppressed (especially in the BN-30 sample). This suggests that the BN coatings primarily act by hindering the cathodic reaction (likely oxygen reduction) rather than blocking both anodic and cathodic processes equally, as can be seen through the increase in the cathodic Tafel slope (βc) in BN-coated samples, particularly for BN-30 (371.4 mV/decade). Thus, herein the BN coating’s role extends beyond that of a simple insulating physical barrier; it likely alters interfacial electrochemical kinetics, possibly through modified surface chemistry, or oxygen and electrolyte access limitations.
For a better illustration, the comparison of Rp and Icorr for all samples is presented in Table 1, which underscores the relationship between coating quality and corrosion resistance. For the BN-30 sample, the values of Rp and Icorr are almost 10 times higher and lower, respectively, than the bare MS sample. Nevertheless, BN-15 and BN-60 also exhibited improved corrosion resistance compared to bare MS; however, they are not as good as compared to BN-30. This is due to the thinner and less uniform layers for BN-15 and the less covered substrate with the thicker structure of BN-60, which gives them moderate protection properties.

4. Conclusions

In this study, we produced different forms of BN coatings on MS via a special arrangement of the MS sample, alumina boat, aluminium shreds, and platinum crucible containing boron powder in a CVD setup, and we evaluated their effectiveness on water contact angle and corrosion resistance. XRD and FTIR validated the production of BN. SEM examination revealed that BN-30 offered the most uniform and dense coverage, moving from needle-like structures in BN-15 to well-formed coral-like and tubular/flower-like morphologies in BN-30 and BN-60, respectively, with both B and N present in the coatings. Water contact angle tests demonstrated improved hydrophobicity, with BN-30 performing optimally with the highest value (~131.3°) of water contact angle following the Cassie–Baxter effect. Electrochemical evaluations highlighted the superior corrosion resistance of BN coatings. BN-30 exhibited the highest polarization resistance (Rp = 25.94 Ω·cm2) and the lowest corrosion current density (Icorr = 0.974 μA/cm2) with an average corrosion rate of 0.445 mpy, outperforming BN-15 and BN-60. This study highlights the potential of BN coatings as anti-icing and advanced anti-corrosion materials with promising applications in sectors that require long-lasting and dependable protection.

Author Contributions

A.N. and M.F.M.: Writing—original draft, Methodology, Investigation, Data curation, Conceptualization, Review, & editing. M.A.R.: Writing—review & editing, Visualization, Validation, Supervision, Project administration. S.M.Z.M.: Software, Formal analysis. S.A.: Methodology, Data curation. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding authors.

Acknowledgments

We thank the University of Punjab, the Higher Education Commission (HEC) of Pakistan, the American University of Sharjah, Sejong University and Gachon University for their assistance.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Sastri, V.S. Challenges in Corrosion: Costs, Causes, Consequences, and Control; John Wiley & Sons: Hoboken, NJ, USA, 2015. [Google Scholar]
  2. Bender, R.; Féron, D.; Mills, D.; Ritter, S.; Bäßler, R.; Bettge, D.; De Graeve, I.; Dugstad, A.; Grassini, S.; Hack, T. Corrosion challenges towards a sustainable society. Mater. Corros. 2022, 73, 1730–1751. [Google Scholar] [CrossRef]
  3. Maqsood, M.F.; Raza, M.A.; Ghauri, F.A.; Rehman, Z.U.; Ilyas, M.T. Corrosion study of graphene oxide coatings on AZ31B magnesium alloy. J. Coat. Technol. Res. 2020, 17, 1321–1329. [Google Scholar] [CrossRef]
  4. Abbas, M.; Shafiee, M. An overview of maintenance management strategies for corroded steel structures in extreme marine environments. Mar. Struct. 2020, 71, 102718. [Google Scholar] [CrossRef]
  5. Al-Amiery, A.; Isahak, W.N.R.W.; Al-Azzawi, W.K. Sustainable corrosion Inhibitors: A key step towards environmentally responsible corrosion control. Ain Shams Eng. J. 2024, 15, 102672. [Google Scholar] [CrossRef]
  6. Fayomi, O.S. Metallurgical Advances in Coatings and Corrosion; CRC Press: Boca Raton, FL, USA, 2024. [Google Scholar]
  7. Ashwathareddy, A.; Rao, S.; Subramaniyam, S.S.; Krishna, P.G.; Rama, K.M.; Kodange, S. Corrosion mitigation of mild steel in acidic medium using liquid crystals: A comprehensive review. Inorg. Chem. Commun. 2024, 169, 113071. [Google Scholar] [CrossRef]
  8. Kadhim, A.; Betti, N.; Al-Bahrani, H.; Al-Ghezi, M.; Gaaz, T.; Kadhum, A.; Alamiery, A. A mini review on corrosion, inhibitors and mechanism types of mild steel inhibition in an acidic environment. Int. J. Corros. Scale Inhib. 2021, 10, 861–884. [Google Scholar]
  9. Aslam, R.; Mobin, M.; Zehra, S.; Aslam, J. A comprehensive review of corrosion inhibitors employed to mitigate stainless steel corrosion in different environments. J. Mol. Liq. 2022, 364, 119992. [Google Scholar] [CrossRef]
  10. Odio, B.; Chinwuko, E.; Chukwuneke, J.; Sinebe, J. Investigation of the effect of corrosion on mild steel in five different environments. Int. J. Sci. Technol. Res. 2014, 3, 306–310. [Google Scholar]
  11. Maqsood, M.F.; Raza, M.A.; Rehman, Z.U.; Abid, M.; Inam, A.; Iqbal, S. Corrosion study of zinc rich epoxy ester paints for cold galvanizing of mild steel. Surf. Rev. Lett. 2021, 28, 2150064. [Google Scholar] [CrossRef]
  12. Caldona, E.B.; Wipf, D.O.; Smith, D.W., Jr. Characterization of a tetrafunctional epoxy-amine coating for corrosion protection of mild steel. Prog. Org. Coat. 2021, 151, 106045. [Google Scholar] [CrossRef]
  13. Attarzadeh, N.; Molaei, M.; Babaei, K.; Fattah-alhosseini, A. New promising ceramic coatings for corrosion and wear protection of steels: A review. Surf. Interfaces 2021, 23, 100997. [Google Scholar] [CrossRef]
  14. Randis, R.; Darmadi, D.B.; Gapsari, F.; Sonief, A.A.A.; Akpan, E.D.; Ebenso, E.E. The potential of nanocomposite-based coatings for corrosion protection of metals: A review. J. Mol. Liq. 2023, 390, 123067. [Google Scholar] [CrossRef]
  15. Farh, H.M.H.; Seghier, M.E.A.B.; Zayed, T. A comprehensive review of corrosion protection and control techniques for metallic pipelines. Eng. Fail. Anal. 2023, 143, 106885. [Google Scholar] [CrossRef]
  16. Nazari, M.H.; Zhang, Y.; Mahmoodi, A.; Xu, G.; Yu, J.; Wu, J.; Shi, X. Nanocomposite organic coatings for corrosion protection of metals: A review of recent advances. Prog. Org. Coat. 2022, 162, 106573. [Google Scholar] [CrossRef]
  17. Lazorenko, G.; Kasprzhitskii, A.; Nazdracheva, T. Anti-corrosion coatings for protection of steel railway structures exposed to atmospheric environments: A review. Constr. Build. Mater. 2021, 288, 123115. [Google Scholar] [CrossRef]
  18. Nadeem, A.; Maqsood, M.F.; Raza, M.A.; Karim, M.R.; Ghafoor, F.; Lee, Y.; Ali, S.; Rehman, M.A.; Khan, M.F. Thermally stable and anti-corrosive polydimethyl siloxane composite coatings based on nanoforms of boron nitride. Inorg. Chem. Commun. 2024, 168, 112989. [Google Scholar] [CrossRef]
  19. Wu, Y.; Wu, Y.; Sun, Y.; Zhao, W.; Wang, L. 2D nanomaterials reinforced organic coatings for marine corrosion protection: State of the art, challenges, and future prospectives. Adv. Mater. 2024, 36, 2312460. [Google Scholar] [CrossRef]
  20. Maqsood, M.F.; Zubair, M.A.A.; Raza, M.A.; Mehdi, S.M.Z.; Lee, N.; Rehman, Z.U.; Park, K.; Bhatti, M.U.; Latif, U.; Tawakkal, A. Fabrication and characterization of graphene oxide and glass fiber-based hybrid epoxy composites. Polym. Compos. 2022, 43, 8072–8083. [Google Scholar] [CrossRef]
  21. Raza, M.A.; Maqsood, M.F.; Rehman, Z.U.; Westwood, A.; Inam, A.; Sattar, M.M.S.; Ghauri, F.A.; Ilyas, M.T. Thermally Reduced Graphene Oxide-Reinforced Acrylonitrile Butadiene Styrene Composites Developed by Combined Solution and Melt Mixing Method. Arab. J. Sci. Eng. 2020, 45, 9559–9568. [Google Scholar] [CrossRef]
  22. Naclerio, A.E.; Kidambi, P.R. A review of scalable hexagonal boron nitride (h-BN) synthesis for present and future applications. Adv. Mater. 2023, 35, 2207374. [Google Scholar] [CrossRef]
  23. Nadeem, A.; Raza, M.A.; Maqsood, M.F.; Ilyas, M.T.; Westwood, A.; Rehman, Z.U. Characterization of boron nitride nanosheets synthesized by boron-ammonia reaction. Ceram. Int. 2020, 46, 20415–20422. [Google Scholar] [CrossRef]
  24. Nadeem, A.; Maqsood, M.F.; Raza, M.A.; Ilyas, M.T.; Iqbal, M.J.; Rehman, Z.U. Binder free boron nitride-based coatings deposited on mild steel by chemical vapour deposition: Anti-corrosion performance analysis. Phys. B Condens. Matter 2021, 602, 412600. [Google Scholar] [CrossRef]
  25. Liu, Y.; Zhu, G.; Qiu, F.; Chen, C.; Liu, L.; Dai, G. Effect of h-BN Orientation on the Corrosion Resistance of Bioinspired Layered Phosphate Composite Coatings. ACS Appl. Nano Mater. 2024, 7, 20733–20744. [Google Scholar] [CrossRef]
  26. Luo, X.; Li, X.; Li, M.; Ding, D.; Tong, L. A bi-layer superhydrophobic coating with long-term anti-corrosion enabled by functionalized hexagonal boron nitride and PDMS-based polyurethane on Mg alloy. Polymer 2024, 315, 127816. [Google Scholar] [CrossRef]
  27. Yu, R.; Yuan, X. Rising of boron nitride: A review on boron nitride nanosheets enhanced anti-corrosion coatings. Prog. Org. Coat. 2024, 186, 107990. [Google Scholar] [CrossRef]
  28. Verma, C.; Dubey, S.; Barsoum, I.; Alfantazi, A.; Ebenso, E.E.; Quraishi, M. Hexagonal boron nitride as a cutting-edge 2D material for additive application in anticorrosive coatings: Recent progress, challenges and opportunities. Mater. Today Commun. 2023, 35, 106367. [Google Scholar] [CrossRef]
  29. Maqsood, M.F.; Mehdi, S.M.Z.; Ashraf, A.; Azhar, U.; Abbas, N.; Raza, M.A.; Amer, M. Binder-Free Hexagonal Boron Nitride Nanosheets (BNNSs) as Protective Coatings for Copper, Steel, and Wood: A Review. Crystals 2025, 15, 99. [Google Scholar] [CrossRef]
  30. Roy, S.; Zhang, X.; Puthirath, A.B.; Meiyazhagan, A.; Bhattacharyya, S.; Rahman, M.M.; Babu, G.; Susarla, S.; Saju, S.K.; Tran, M.K. Structure, properties and applications of two-dimensional hexagonal boron nitride. Adv. Mater. 2021, 33, 2101589. [Google Scholar] [CrossRef]
  31. Li, M.; Huang, G.; Chen, X.; Yin, J.; Zhang, P.; Yao, Y.; Shen, J.; Wu, Y.; Huang, J. Perspectives on environmental applications of hexagonal boron nitride nanomaterials. Nano Today 2022, 44, 101486. [Google Scholar] [CrossRef]
  32. Mehdi, S.M.Z.; Maqsood, M.F.; Dahshan, A.; Ahmad, S.; Ur Rehman, M.; Lee, N.; Rehman, M.A.; Khan, M.F. Emerging boron nitride nanosheets: A review on synthesis, corrosion resistance coatings, and their impacts on the environment and health. Rev. Adv. Mater. Sci. 2024, 63, 20240075. [Google Scholar] [CrossRef]
  33. Mane, S.K.B.; Shaishta, N.; Manjunatha, G. Biocompatibility, toxicity evaluations, environmental and health impact of hexagonal boron nitride. In Hexagonal Boron Nitride; Elsevier: Amsterdam, The Netherlands, 2024; pp. 613–636. [Google Scholar]
  34. Jiang, X.-F. Recent progress on fabrications and applications of boron nitride nanomaterials: A review. J. Mater. Sci. Technol. 2015, 31, 589–598. [Google Scholar] [CrossRef]
  35. Seo, J.-W.; Pophali, A.; An, S.; Liang, C.S.L.; Li, S.; Liu, H.; Kim, J.; An, K.; Kim, J.; Kim, T. Fundamental structural study of hexagonal boron nitride (h-BN) and boron nitride nanotube (BNNT) at low and high temperatures. J. Mol. Struct. 2025, 1319, 139545. [Google Scholar] [CrossRef]
  36. Han, N.; Wang, S.; Rana, A.K.; Asif, S.; Klemeš, J.J.; Bokhari, A.; Long, J.; Thakur, V.K.; Zhao, X. Rational design of boron nitride with different dimensionalities for sustainable applications. Renew. Sustain. Energy Rev. 2022, 170, 112910. [Google Scholar] [CrossRef]
  37. Wadhwa, G.K.; Late, D.J.; Charhate, S.; Sankhyan, S.B. 1D and 2D Boron Nitride Nano Structures: A Critical Analysis for Emerging Applications in the Field of Nanocomposites. ACS Omega 2024, 9, 26737–26761. [Google Scholar] [CrossRef]
  38. Mapleback, B.J.; Brack, N.; Thomson, L.; Spencer, M.J.; Osborne, D.A.; Doshi, S.; Thostenson, E.T.; Rider, A.N. Development of stable boron nitride nanotube and hexagonal boron nitride dispersions for electrophoretic deposition. Langmuir 2020, 36, 3425–3438. [Google Scholar] [CrossRef]
  39. Sukanya, R.; Barwa, T.N.; Luo, Y.; Dempsey, E.; Breslin, C.B. Emerging layered materials and their applications in the corrosion protection of metals and alloys. Sustainability 2022, 14, 4079. [Google Scholar] [CrossRef]
  40. Zhang, Y.; Sun, J.; Xiao, X.; Wang, N.; Meng, G.; Gu, L. Graphene-like two-dimensional nanosheets-based anticorrosive coatings: A review. J. Mater. Sci. Technol. 2022, 129, 139–162. [Google Scholar] [CrossRef]
  41. Shang, C.; Sang, D.; Li, C.; Zou, L.; Wu, J.; Wang, Q. 2D materials for marine corrosion protection: A review. APL Mater. 2024, 12, 060601. [Google Scholar] [CrossRef]
  42. Liu, H.; Yan, M.; Jing, W.; Zeng, G.; Gengxin, X.; Pu, X.; Fu, Y.; Peng, X.; Wang, H.; Lai, C. Hexagonal boron nitride for extreme environment application. Diam. Relat. Mater. 2024, 148, 111410. [Google Scholar] [CrossRef]
  43. Tang, X.; Wang, H.; Liu, C.; Zhu, X.; Gao, W.; Yin, H. Direct growth of hexagonal boron nitride nanofilms on stainless steel for corrosion protection. ACS Appl. Nano Mater. 2021, 4, 12024–12033. [Google Scholar] [CrossRef]
  44. Deshmukh, K.; Pandey, M.; Hussain, C.M. Hexagonal Boron Nitride: Synthesis, Properties, and Applications; Elsevier: Amsterdam, The Netherlands, 2024. [Google Scholar]
  45. Farhan, M.; Subhan, M.; Naseem, S.; Riaz, S.; Awan, R.; Mujahid, A.; Afzal, A. Polycrystalline boron nitride microflowers for non-invasive vitamin B3 (nicotinamide) sensing. Diam. Relat. Mater. 2025, 155, 112296. [Google Scholar] [CrossRef]
  46. Liu, Z.; Rhimi, B.; Liu, Z.; Mao, L.; Zhou, M.; Jiang, Z.; Jiang, Z. Modulating Defect Concentration of Boron Nitride Flowers for CO2 Photoreduction. Inorg. Chem. 2025, 64, 3445–3453. [Google Scholar] [CrossRef] [PubMed]
  47. Pakdel, A.; Zhi, C.; Bando, Y.; Nakayama, T.; Golberg, D. Boron Nitride Nanosheet Coatings with Controllable Water Repellency. ACS Nano 2011, 5, 6507–6515. [Google Scholar] [CrossRef]
  48. Kumar Verma, A.; Govind Rajan, A. Surface roughness explains the observed water contact angle and slip length on 2D hexagonal boron nitride. Langmuir 2022, 38, 9210–9220. [Google Scholar] [CrossRef]
  49. Yang, F.; McQuain, A.D.; Kumari, A.; Gundurao, D.; Liu, H.; Li, L. Understanding the intrinsic water wettability of hexagonal boron nitride. Langmuir 2024, 40, 6445–6452. [Google Scholar] [CrossRef]
  50. McLean, B.; Eveleens, C.A.; Mitchell, I.; Webber, G.B.; Page, A.J. Catalytic CVD synthesis of boron nitride and carbon nanomaterials–synergies between experiment and theory. Phys. Chem. Chem. Phys. 2017, 19, 26466–26494. [Google Scholar] [CrossRef]
  51. Ma, R.; Bando, Y.; Sato, T.; Kurashima, K. Growth, morphology, and structure of boron nitride nanotubes. Chem. Mater. 2001, 13, 2965–2971. [Google Scholar] [CrossRef]
  52. Pakdel, A.; Zhi, C.; Bando, Y.; Nakayama, T.; Golberg, D. A comprehensive analysis of the CVD growth of boron nitride nanotubes. Nanotechnology 2012, 23, 215601. [Google Scholar] [CrossRef]
  53. Gohier, A.; Ewels, C.; Minea, T.; Djouadi, M. Carbon nanotube growth mechanism switches from tip-to base-growth with decreasing catalyst particle size. Carbon 2008, 46, 1331–1338. [Google Scholar] [CrossRef]
  54. Yoshida, H.; Takeda, S.; Uchiyama, T.; Kohno, H.; Homma, Y. Atomic-scale in-situ observation of carbon nanotube growth from solid state iron carbide nanoparticles. Nano Lett. 2008, 8, 2082–2086. [Google Scholar] [CrossRef]
  55. Chen, Y.; Zhang, J. Diameter controlled growth of single-walled carbon nanotubes from SiO2 nanoparticles. Carbon 2011, 49, 3316–3324. [Google Scholar] [CrossRef]
  56. Lee, C.H.; Xie, M.; Kayastha, V.; Wang, J.; Yap, Y.K. Patterned growth of boron nitride nanotubes by catalytic chemical vapor deposition. Chem. Mater. 2010, 22, 1782–1787. [Google Scholar] [CrossRef]
  57. Ma, R.; Bando, Y.; Sato, T. Coaxial nanocables: Fe nanowires encapsulated in BN nanotubes with intermediate C layers. Chem. Phys. Lett. 2001, 350, 1–5. [Google Scholar] [CrossRef]
  58. Lourie, O.R.; Jones, C.R.; Bartlett, B.M.; Gibbons, P.C.; Ruoff, R.S.; Buhro, W.E. CVD growth of boron nitride nanotubes. Chem. Mater. 2000, 12, 1808–1810. [Google Scholar] [CrossRef]
  59. Caneva, S.; Weatherup, R.S.; Bayer, B.C.; Blume, R.; Cabrero-Vilatela, A.; Braeuninger-Weimer, P.; Martin, M.-B.; Wang, R.; Baehtz, C.; Schloegl, R. Controlling catalyst bulk reservoir effects for monolayer hexagonal boron nitride CVD. Nano Lett. 2016, 16, 1250–1261. [Google Scholar] [CrossRef]
  60. Jana, M.; Singh, R.N. Progress in CVD synthesis of layered hexagonal boron nitride with tunable properties and their applications. Int. Mater. Rev. 2018, 63, 162–203. [Google Scholar] [CrossRef]
  61. Caneva, S.; Weatherup, R.S.; Bayer, B.C.; Brennan, B.; Spencer, S.J.; Mingard, K.; Cabrero-Vilatela, A.; Baehtz, C.; Pollard, A.J.; Hofmann, S. Nucleation control for large, single crystalline domains of monolayer hexagonal boron nitride via Si-doped Fe catalysts. Nano Lett. 2015, 15, 1867–1875. [Google Scholar] [CrossRef]
  62. McLean, B.; Webber, G.B.; Page, A.J. Energy and Charge Transfer at the Boron Nitride Nanotube—Catalyst Growth Interface. J. Phys. Chem. C 2020, 124, 11662–11668. [Google Scholar] [CrossRef]
  63. McLean, B.; Webber, G.B.; Page, A.J. Boron nitride nanotube nucleation via network fusion during catalytic chemical vapor deposition. J. Am. Chem. Soc. 2019, 141, 13385–13393. [Google Scholar] [CrossRef]
  64. McLean, B. Growth Mechanisms of Boron Nitride Nanotubes during Chemical Vapour Deposition. Ph.D Thesis, University of Newcastle, New South Wales, Australia, 2019. [Google Scholar]
  65. Lee, C.H.; Drelich, J.; Yap, Y.K. Superhydrophobicity of boron nitride nanotubes grown on silicon substrates. Langmuir 2009, 25, 4853–4860. [Google Scholar] [CrossRef]
  66. Kyzas, G.Z.; Mitropoulos, A.C. Advanced Low-Cost Separation Techniques in Interface Science; Academic Press: Cambridge, MA, USA, 2019; Volume 30. [Google Scholar]
  67. Fillion, R.; Riahi, A.; Edrisy, A. A review of icing prevention in photovoltaic devices by surface engineering. Renew. Sustain. Energy Rev. 2014, 32, 797–809. [Google Scholar] [CrossRef]
  68. Zhao, W.; Lu, H.; Li, C. Composite hollow fiber membrane dehumidification: A review on membrane module, moisture permeability and self-cleaning performance. Int. J. Heat Mass Transf. 2021, 181, 121832. [Google Scholar] [CrossRef]
  69. Wang, Z.; Paul, S.; Stein, L.H.; Salemi, A.; Mitra, S. Recent developments in blood-compatible superhydrophobic surfaces. Polymers 2022, 14, 1075. [Google Scholar] [CrossRef]
  70. Maqsood, M.F.; Raza, M.A.; Rehman, Z.U.; Tayyeb, A.; Makhdoom, M.A.; Ghafoor, F.; Latif, U.; Khan, M.F. Role of Solvent Used in Development of Graphene Oxide Coating on AZ31B Magnesium Alloy: Corrosion Behavior and Biocompatibility Analysis. Nanomaterials 2022, 12, 3745. [Google Scholar] [CrossRef]
Surfaces 08 00042 g001
Figure 1. Schematic of BN coating and growth on MS substrate.
Figure 1. Schematic of BN coating and growth on MS substrate.
Surfaces 08 00042 g001
Surfaces 08 00042 g002
Figure 2. (a) XRD and (b) FTIR spectrum of MS-coated samples.
Figure 2. (a) XRD and (b) FTIR spectrum of MS-coated samples.
Surfaces 08 00042 g002
Surfaces 08 00042 g003
Figure 3. SEM images of MS-coated samples (a–c) BN-15, (d–f) BN-30, and (g–i) BN-60 (scale 100 µm, 10 µm and 2 µm). The morphology of BN is correlated with that of the flowers.
Figure 3. SEM images of MS-coated samples (a–c) BN-15, (d–f) BN-30, and (g–i) BN-60 (scale 100 µm, 10 µm and 2 µm). The morphology of BN is correlated with that of the flowers.
Surfaces 08 00042 g003
Surfaces 08 00042 g004
Figure 4. EDX and elemental mapping analysis of MS coated samples (a) BN-15, (b) BN-30 and (c) BN-60 (scale 10 µm and 5 µm).
Figure 4. EDX and elemental mapping analysis of MS coated samples (a) BN-15, (b) BN-30 and (c) BN-60 (scale 10 µm and 5 µm).
Surfaces 08 00042 g004
Surfaces 08 00042 g005
Figure 5. Water contact angle of (a) bare MS, (b) BN-15, (c) BN-30, and (d) BN-60 samples.
Figure 5. Water contact angle of (a) bare MS, (b) BN-15, (c) BN-30, and (d) BN-60 samples.
Surfaces 08 00042 g005
Surfaces 08 00042 g006
Figure 6. Potentiodynamic polarization curves of bare MS and BN-coated samples.
Figure 6. Potentiodynamic polarization curves of bare MS and BN-coated samples.
Surfaces 08 00042 g006
Table 1. Kinetic parameters obtained from the Tafel extrapolation method.
Table 1. Kinetic parameters obtained from the Tafel extrapolation method.
Sampleβa
(mV/Decade)		βc
(mV/Decade)		Icorr
(μA/cm2)		Εcorr
(mV)		Rp
(Ω·cm2)		Avg. Corrosion Rate (mpy)
Bare MS73.30325.79.450 ± 0.7518.502.7494.316
BN-1580.10348.75.170 ± 0.082−21.705.4712.363
BN-3069.00371.40.974 ± 0.023−33.8025.940.445
BN-6066.90468.64.080 ± 0.047−21.906.2301.867
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Nadeem, A.; Maqsood, M.F.; Raza, M.A.; Mehdi, S.M.Z.; Ahmad, S. Hydrophobic Boron Nitride Nanoflower Coatings on Mild Steel Surfaces. Surfaces 2025, 8, 42. https://doi.org/10.3390/surfaces8030042

AMA Style

Nadeem A, Maqsood MF, Raza MA, Mehdi SMZ, Ahmad S. Hydrophobic Boron Nitride Nanoflower Coatings on Mild Steel Surfaces. Surfaces. 2025; 8(3):42. https://doi.org/10.3390/surfaces8030042

Chicago/Turabian Style

Nadeem, Aamir, Muhammad Faheem Maqsood, Mohsin Ali Raza, Syed Muhammad Zain Mehdi, and Shahbaz Ahmad. 2025. "Hydrophobic Boron Nitride Nanoflower Coatings on Mild Steel Surfaces" Surfaces 8, no. 3: 42. https://doi.org/10.3390/surfaces8030042

APA Style

Nadeem, A., Maqsood, M. F., Raza, M. A., Mehdi, S. M. Z., & Ahmad, S. (2025). Hydrophobic Boron Nitride Nanoflower Coatings on Mild Steel Surfaces. Surfaces, 8(3), 42. https://doi.org/10.3390/surfaces8030042

Article Metrics

Back to TopTop