Ceramics

16 pages, 11682 KB

Open AccessArticle

Synthesis of RE³⁺ (RE = Ho, Tb, Pr)-Doped Alumina Ceramic Coatings by Plasma Electrolytic Oxidation of Aluminum: Investigation of Photocatalytic Performance

by Stevan Stojadinović, Darwin Augusto Torres-Ceron, Sebastian Amaya-Roncancio and Nenad Radić

Ceramics 2026, 9(4), 42; https://doi.org/10.3390/ceramics9040042 - 21 Apr 2026

Viewed by 802

Abstract

Porous, crystalline gamma-Al₂O₃ coatings with a thickness of (6 ± 0.5) μm and a uniform distribution of rare earth (RE) dopants are synthesized by plasma electrolytic oxidation of aluminum at a current density of 150 mA/cm² in a boric [...] Read more.

Porous, crystalline gamma-Al₂O₃ coatings with a thickness of (6 ± 0.5) μm and a uniform distribution of rare earth (RE) dopants are synthesized by plasma electrolytic oxidation of aluminum at a current density of 150 mA/cm² in a boric acid and borax (BB) solution containing added RE oxide particles (Ho₂O₃, Tb₄O₇, and Pr₆O₁₁) at concentrations of 1, 2, and 4 g/L. The concentration of RE oxide particles in the BB solution determines the amount of RE elements incorporated into the coatings but does not significantly affect their surface morphology, crystal structure, or light absorption properties. The coatings exhibit high absorption in the middle/near-ultraviolet region, characteristic of Al₂O₃. Typical 4f-4f transitions of Ho³⁺, Tb³⁺, and Pr³⁺ are observed in the photoluminescence spectra. Photocatalytic evaluations using methyl orange degradation under simulated solar irradiation show that RE doping significantly enhances photocatalytic efficiency. Peak degradation efficiencies are achieved at a concentration of 4 g/L for all RE oxides. After 8 h of irradiation, maximum degradation reaches 88%, 92%, and 85% with pseudo-first-order rate constants (k_app) of about 0.274 h⁻¹, 0.339 h⁻¹, and 0.232 h⁻¹ for coatings synthesized in BB with 4 g/L Ho₂O₃, Tb₄O₇, or Pr₆O₁₁, respectively. In comparison, the pristine Al₂O₃ coating achieves only about 50% degradation (k_app ≈ 0.087 h⁻¹). Photoluminescence indicates that RE³⁺ ions serve as effective charge-carrier traps, suppressing electron–hole pair recombination. RE-doped Al₂O₃ coatings demonstrate exceptional structural stability and reusability over six cycles, highlighting their potential for sustainable wastewater remediation. Full article

► Show Figures

Figure 1

5 pages, 216 KB

Open AccessEditorial

Mechanical Behavior and Reliability of Engineering Ceramics

by Malika Saâdaoui

Ceramics 2026, 9(4), 41; https://doi.org/10.3390/ceramics9040041 - 18 Apr 2026

Cited by 1 | Viewed by 981

Abstract

Engineering ceramics are successfully used as structural or functional materials in a wide range of technical and biomedical applications [...] Full article

(This article belongs to the Special Issue Mechanical Behavior and Reliability of Engineering Ceramics)

12 pages, 17611 KB

Open AccessArticle

Effect of MoO₃ Doping on the Microstructure and Magnetic Properties of Mn_0.816Zn_0.091Fe_2.093Mo_xO₄

by Shuxin Liu, Xinglian Song, Changchun Wang, Wenju Liao, Zhen Wang and Haomiao Yu

Ceramics 2026, 9(4), 40; https://doi.org/10.3390/ceramics9040040 - 14 Apr 2026

Viewed by 662

Abstract

The traditional solid-state method was employed in this study to prepare Mn-Zn ferrite. By adjusting the sintering temperature and the MoO₃ doping ratio, the evolution of its structural and magnetic properties was systematically investigated. Fe₂O₃, MnO, and ZnO [...] Read more.

The traditional solid-state method was employed in this study to prepare Mn-Zn ferrite. By adjusting the sintering temperature and the MoO₃ doping ratio, the evolution of its structural and magnetic properties was systematically investigated. Fe₂O₃, MnO, and ZnO were used as the main raw materials, with MoO₃ serving as an additive. MoO₃ was doped at molar ratios ranging from 0 to 1000 ppm under experimental conditions involving a sintering temperature between 1125 °C and 1165 °C and an oxygen concentration of 1.5%. The addition of an appropriate amount of MoO₃ led to an increase in the Q value, which consequently resulted in a reduction in the loss. The formation of a single-phase spinel structure was confirmed by X-ray diffraction analysis. Observations of the surface morphology revealed that the grain size also increased with the increase in MoO₃ content, a trend consistent with the enhanced grain growth kinetics at higher MoO₃ levels. In this study, a Mn-Zn ferrite material with excellent comprehensive performance was successfully prepared under the optimal conditions of a sintering temperature of 1150 °C and a MoO₃ doping concentration of 500 ppm. A Q value of 22.3 was obtained for this material at 25 °C, while a Q value of 15.7 was obtained at 100 °C. At room temperature, a Q value of 192.4 was measured at a test frequency of 500 kHz, and a Q value of 137.2 was measured at 1 MHz. At a frequency of 500 kHz, a loss of 27.1 kW/m³ was observed at 25 °C, and a loss of 53.6 kW/m³ was observed at 100 °C. At a frequency of 1 MHz, a loss of 88.2 kW/m³ was recorded at 25 °C, while a loss of 183.7 kW/m³ was recorded at 100 °C. Additionally, the lattice constant was stabilized in the range of 8.52–8.53 Å, indicating favorable structural stability. Full article

(This article belongs to the Special Issue Advances in Electronic Ceramics, 2nd Edition)

► Show Figures

Figure 1

60 pages, 10136 KB

Open AccessReview

Advances in High-Performance Ceramic Materials for Aerospace and Defence Applications: A State-of-the-Art Review

by Alfredo Aguilar-Elguezabal, Armando Reyes-Rojas, Hilda Esperanza Esparza-Ponce, Daniel Lardizábal-Gutiérrez and Miguel Humberto Bocanegra-Bernal

Ceramics 2026, 9(4), 39; https://doi.org/10.3390/ceramics9040039 - 2 Apr 2026

Cited by 2 | Viewed by 4173

Abstract

Ceramic materials are indispensable to aerospace and defence technologies, where structural and functional components are required to withstand extreme thermal, mechanical, and chemically aggressive environments. Traditionally valued for their exceptional thermal stability, oxidation resistance, and corrosion resistance, ceramics have nonetheless been constrained by [...] Read more.

Ceramic materials are indispensable to aerospace and defence technologies, where structural and functional components are required to withstand extreme thermal, mechanical, and chemically aggressive environments. Traditionally valued for their exceptional thermal stability, oxidation resistance, and corrosion resistance, ceramics have nonetheless been constrained by their inherent brittleness, which has limited their widespread adoption in load-bearing structural applications. This review surveys the principal tough ceramic systems currently employed in aerospace and defence, including SiC, Al₂O₃, ZrO₂, Si₃N₄, SiC/SiC composites, and ultra-high-temperature ceramics (UHTCs) such as ZrB₂ and HfB₂. In parallel, it outlines advanced processing and manufacturing routes that enable enhanced microstructural control, improved reliability, and scalability for industrial deployment. Special attention is devoted to thermal and environmental barrier coatings (TBCs and EBCs), which provide critical protection against oxidation, corrosion, and severe thermal cycling in propulsion, power-generation, and hypersonic systems. Finally, the review highlights key material selection criteria for aerospace and defence platforms and discusses emerging trends that integrate tough ceramics with next-generation manufacturing technologies, underscoring their pivotal role in enabling high-performance, durable, and resilient systems for future extreme-environment applications. Full article

(This article belongs to the Special Issue Advances in Ceramics, 3rd Edition)

► Show Figures

Graphical abstract

18 pages, 2070 KB

Open AccessArticle

High-Performance Magnetic Mining Waste-Based Geopolymeric Membrane Coated with Silver Molybdate: Processing, Characterization, and Filtration Behavior

by Daniela Gier Della Rocca, Victor de Aguiar Pedott, Fernanda Cristina Fraga, Adriano da Silva, Rosely Aparecida Peralta, Enrique Rodríguez-Castellón, Natália Ueda Yamaguchi, Bruno Francisco Oechsler and Regina de Fátima Peralta Muniz Moreira

Ceramics 2026, 9(4), 38; https://doi.org/10.3390/ceramics9040038 - 29 Mar 2026

Viewed by 1306

Abstract

Membrane technology is a highly efficient, cost-effective, and chemical-free process, leading to its widespread application across various fields. However, the high capital cost of traditional ceramic benchmarks remains a barrier. This study addresses this challenge by engineering a low-cost, waste-derived geopolymeric membrane functionalized [...] Read more.

Membrane technology is a highly efficient, cost-effective, and chemical-free process, leading to its widespread application across various fields. However, the high capital cost of traditional ceramic benchmarks remains a barrier. This study addresses this challenge by engineering a low-cost, waste-derived geopolymeric membrane functionalized with a silver molybdate (Ag₂MoO₄) catalytic coating for the removal of trimethoprim (TMP), a persistent emerging contaminant. Systematic filtration assays for the removal of TMP (100 mg·L⁻¹, pH 4) revealed the role of the Ag₂MoO₄ layer as a performance intensifier, yielding a 26% increase in initial permeate flux and a 33% improvement in the selectivity compared to the pristine support, while maintaining robust rejection efficiency. Comprehensive characterization attributes these enhancements to synergistic effects between increased surface hydrophilicity and favorable solute–catalyst interfacial interactions. Furthermore, a fouling analysis using Hermia’s models indicated the simultaneous operation of multiple blocking mechanisms, a phenomenon linked to the non-uniform nature of the coating and subsequent formation of preferential flow paths. Overall, the incorporation of the silver molybdate coating effectively improved the membrane’s flux performance and selectivity. These findings demonstrate that integrating catalytic coatings onto waste-based geopolymer frameworks provides a scalable, circular-economy-aligned strategy for advanced wastewater treatment, balancing high-flux performance with the efficient removal of recalcitrant pharmaceuticals. Full article

(This article belongs to the Special Issue The Production Processes and Applications of Geopolymers, 2nd Edition)

► Show Figures

Figure 1

17 pages, 4627 KB

Open AccessArticle

A Novel Bi₂O₃-TeO₂-B₂O₃-CuO Glass for Copper Metallization of Si₃N₄: Wettability, Thermal Stability, and Bonding Performance

by Chaochen Chen, Fang Lei, Shiqing Dang, Hongyang Zhang, Ying Shi and Haohong Chen

Ceramics 2026, 9(4), 37; https://doi.org/10.3390/ceramics9040037 - 26 Mar 2026

Viewed by 994

Abstract

To address the lack of suitable glass systems for silicon nitride (Si₃N₄) surface metallization, which requires high wettability and thermal stability, and robust bonding between the copper layer and the ceramic substrate, a novel Bi₂O₃-TeO [...] Read more.

To address the lack of suitable glass systems for silicon nitride (Si₃N₄) surface metallization, which requires high wettability and thermal stability, and robust bonding between the copper layer and the ceramic substrate, a novel Bi₂O₃-TeO₂-B₂O₃-CuO glass system was developed. This study systematically investigated the influence of Bi₂O₃ concentration, glass properties, optimized paste composition, and brazing mechanism using phase analysis, microstructural characterization, particle size statistics, thermal analysis, and tensile testing. An optimal glass composition containing 20 mol% Bi₂O₃ was identified, exhibiting high thermal stability (ΔT = 224 °C) and a coefficient of thermal expansion of 9.63 × 10⁻⁶ °C⁻¹. At a brazing temperature of 750 °C, the glass demonstrated excellent wettability with a contact angle of 27°. A conductive paste comprising 94 wt% Cu and 6 wt% glass yielded a thick film with a minimum resistivity of 6.25 μΩ·cm and a maximum tensile strength of 25.2 MPa. Mechanism analysis revealed that the superior wettability drives the liquid glass phase to form a thin intermediate layer that significantly reinforces adhesion. These findings contribute to the research and development of subsequent novel glass systems with superior performance. Full article

(This article belongs to the Special Issue Advances in Ceramics, 3rd Edition)

► Show Figures

Figure 1

13 pages, 3417 KB

Open AccessArticle

Design of a Chemical-Reaction Ceramic Paste, from Electric Arc Furnace Steel Slag and Potassium Hydrophosphate, for Applications in Monolithic Objects

by Carlos Andres Cardenas Balaguera, Andres Felipe Rubiano-Navarrete, Pilar Astrid Ramos Casas and Lina Paola Espitia López

Ceramics 2026, 9(4), 36; https://doi.org/10.3390/ceramics9040036 - 24 Mar 2026

Viewed by 651

Abstract

The research focuses on the development of chemically bonded phosphate ceramics using potassium hydrophosphate and steel slag (EAF) as raw materials. The objective is to scale up the laboratory results to design a ceramic paste suitable for architectural monolithic products, promoting the recycling [...] Read more.

The research focuses on the development of chemically bonded phosphate ceramics using potassium hydrophosphate and steel slag (EAF) as raw materials. The objective is to scale up the laboratory results to design a ceramic paste suitable for architectural monolithic products, promoting the recycling of EAF steel slag. The methodology includes field visits, grinding and sieving of raw materials, and the fabrication of specimens following ASTM standards. The laboratory results from existing studies on multiphase phosphate cements from steel slags indicate that exothermic reactions and the increase in reactants can affect process scaling. Furthermore, shaping methods such as casting and pressing are evaluated, where pressing proves to be the most suitable for this type of phosphate cement as it increases the material’s mechanical properties (compressive strength), reduces porosity, and generates a greater utilization of the EAF steel slag residue. Taking into account Colombian technical standards regarding the minimum compressive strength that a monolithic architectural object must withstand for structural and non-structural use, the results obtained in this research allow us to conclude that this material can indeed be used for architectural purposes. Full article

► Show Figures

Figure 1

Journal Menu

Journal Browser

Ceramics, Volume 9, Issue 4 (April 2026) – 7 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI