In this study, novel porous LaPO4 ceramics possessing closed spherical pores and thin pore walls have been firstly synthesized using the particle-stabilized foaming method. Affected by the calcination temperature together with solid loading, the obtained porous LaPO4 ceramics exhibit high porosity (81.69–94.21 %), very low thermal conductivity (κ) (0.124–0.398 W m−1 K−1) and relatively high compressive strength (0.886–9.30 MPa). When the calcination temperature and solid loading are 1500 °C and 35 wt%, optimized porous LaPO4 ceramics achieve a better balance between thermal conductivity (0.160 W m−1 K−1) and compressive strength (2.07 MPa). Based on this, the prediction model for the thermal conductivity is screened and the thermal insulating capability is further verified. This work suggests that porous LaPO4 ceramics have the potential to be applied as thermal insulation material in the future.

As the hydrogen source of carbon-free fuel cells, the key to realize the green and low-energy decomposition hydrogen production process is to select materials with excellent catalytic performance for ammonia dehydrogenation. In this study, the rare earth element lanthanum (La) was doped onto the surface of Al2O3 by the impregnation method. The aforementioned material was subsequently used as a new material for the synthesis of single metal Co catalysts that catalyzed ammonia decomposition. Various characterization techniques (XRD, HRTEM, N2 physical adsorption-desorption, ICP, XPS, SEM, H2-TPR) were employed to investigate the relationship between the structure and performance of Co/La–Al2O3 catalysts. The findings indicated that the 10Co/La(5)-Al2O3 catalyst was the most active. Under the conditions of 550 °C and 9000 mL h−1·gcat−1, the conversion of ammonia reached 90 %, and the yield of hydrogen reached 8.9 mmol·gcat−1·min−1. A perovskite-type metal oxide layer of LaAlO3 was generated on the surface of Al2O3 support after doping the appropriate amount of lanthanum (5 %), which directly affects the catalytic performance of the catalyst. The small amount of LaAlO3 optimized the strong interaction between the metal Co and the supports, thereby enhancing catalytic performance. While stabilizing the active component Co, XPS and H2-TPR also implied that the presence of La could enhance the electron transfer between the support and Co, as well as facilitate the desorption of nitrogen and hydrogen products, therefore, the low temperature activity of Co/La–Al2O3 catalyst can be improved. The ammonia decomposition efficiency of the catalyst doped with 5 % wt La was much higher than that of the catalyst without La incorporation. The simple modified support developed by us, which loads a monoatomic Co catalyst, provides a new approach for the development of high-activity transition metal catalysts.

Smart polymeric coatings play a crucial role in protecting steel surfaces from corrosion and wear. One of progressive smart behavior is self-healing behavior especially in self-healing epoxy coatings. Creating or improving the second smart behavior is known as a new trend for these smart materials. This study aims to investigate the effects of ZrO2 nanoparticles on the self-lubricating behavior as the second smart behavior of the linseed oil-loaded microcapsule/epoxy composite coatings. To do so, the in-situ polymerization method was used for the synthesis of linseed oil-loaded microcapsule. Results showed that the average size of prepared linseed oil-loaded microcapsules was 563 nm. The composite coatings were prepared by different content of ZrO2 nanoparticles (0, 3, 6, 9, 12, and 15 wt%) and constant content of linseed oil-loaded microcapsules (5 wt%). The tribological performance of samples was studied using pin-on-disk test. The worn surface of the samples was also studied using field emission scanning electron microscope (FESEM) images. Results proved that the frictional coefficient and wear rate of the samples were significantly decreased by increasing the concentrations of the ZrO2 nanoparticles up to 9 wt%. The lowest friction coefficient and wear rate values of 0.085 and 0.142 × 10−6 mm3/Nm were obtained for 5 wt% linseed oil-loaded microcapsules/epoxy with 9 wt% ZrO2 which were about 82 % and 88 % lower than those of pure epoxy coating.

Nighttime driving safety is a key focus in transportation research due to accidents caused by drivers' inability to clearly see road obstacles, leading to delayed or incorrect decisions. To address this, the use of mechanoluminescent materials on surfaces like roads and buildings offers a potential solution for better object contour detection in poor visibility. This study investigates the use of SrAl2O4 as a phosphor matrix, exploring its luminescence characteristics and the effects of doping with Eu2+ and Dy3+. The optimal doping ratios were determined to be 2 % Eu and 1 % Dy by trap modulation, producing phosphors with significant mechanical luminescence and a prolonged afterglow. Spectroscopic analysis and image assessment demonstrated a visible afterglow lasting up to 60 min, along with impressive mechanical luminescence performance. By combining the developed SrAl2O4:Eu2+, Dy3+ phosphor-based coating with polydimethylsiloxane, a real-time surface stress sensing system was devised utilizing digital camera and other optical sensors. This advancement facilitates the visualization of stresses in complex or confined environments, potentially improving nighttime driving safety through enhanced object contour detection.

Fluorescence intensity ratio (FIR) thermometers have obtained great attention in industrial production, medical diagnosis and scientific research. However, the sensitivity has a large decline at high temperatures, which seriously limits the practical applications. Here, the Yb,Er,Tm:Sc2O3 single crystal fibers were grown by laser-heated pedestal growth (LHPG) technique and its multi-mode FIR thermometry based on thermal coupled energy levels (TCLs) and non-thermal coupled energy levels (NTCLs) has been well demonstrated. The temperature measuring range of Yb,Er,Tm:Sc2O3 single crystal fibers covers 298–973 K, with an increase of 2 orders of magnitude in absolute sensitivity. The relative sensitivity is higher than 0.02 % K−1 in the whole T-range of 298∼973 K, with a maximum value of 1.02 % K−1. Especially at the high temperatures of 973 K, it can still maintain 0.31 % K−1. This work proposes an innovative fluorescence intensity ratio detection strategy to achieve complementary disadvantages between TCLs and NTCLs and provides an effective method for improving detection sensitivity.

This research aims to broaden the scope of self-lubricating wear-resistant coatings for applications in diverse industries such as automotive, metallurgy, power, and aerospace. Employing laser cladding technology, we successfully fabricated high-performance self-lubricating ceramic composite coatings. A comprehensive investigation was conducted to understand the inhibitory effect of Cu on the thermal decomposition of MoS2, and the study systematically explored the relationship between powder composition, coating structure, and organizational properties. The mechanisms behind friction reduction and wear resistance were unveiled, shedding light on the formation of the MoS2 self-lubricating protective film. Research findings reveal that during the laser cladding process, Cu and Ni undergo solid solution, resulting in the formation of the Cu–Ni alloy phase and crystal refinement. The MoS2 aggregation area exhibits a fine dendritic structure, while the dispersion area showcases coarse dendritic and cellular crystals. The addition of Cu and MoS2 influences the content of the MxCy phase and the thermal decomposition of MoS2. The incorporation of Cu increases the average coating hardness, whereas MoS2 addition decreases it; nevertheless, the Cu/MoS2 coating hardness is enhanced by at least 6.4 %. Cu significantly improves the coating's wear resistance, with a relatively smaller impact on friction reduction. MoS2 functions as a friction-reducing phase during wear, effectively preventing the peeling of hard phases and reducing the friction coefficient. Cu is uniformly distributed in the coating, experiencing solid solution strengthening, reducing adhesive region areas, and minimizing wear debris generation. MoS2, although unevenly distributed, forms intermittent lubricating films on the surface. The lubricating film of the Cu/MoS2 coating remains stable, preventing mutual contact of the friction surface and concurrently reducing the friction coefficient and wear amount. While the study successfully prepared a self-lubricating ceramic coating with excellent wear resistance, some surface quality defects persist. Further optimization of the preparation method was achieved through ultrasound-assisted technology.

In the conducted research, a one-step hydrothermal synthesis of pure and titanium-doped tin dioxide quantum dots is elaborated upon, with a thorough analysis of their structural, optical, morphological, and photocatalytic properties undertaken using advanced analytical techniques. Through X-ray Diffraction XRD, the crystalline nature and phase purity of the tetragonal structures of SnDs were confirmed, with the crystallite sizes measured at 3.0 nm for SnD1 and 7.66 nm for SnD2, following treatments at 240°C and 300°C, respectively. The structural integrity of SnO2 was maintained despite titanium doping. FTIR spectroscopy verified the existence of specific vibrational modes indicative of surface hydroxyl groups. HRTEM images revealed the spherical morphology of particles, with diameters of 3.5 nm for SnD1 and 9.1 nm for SnD2. Optical band gaps, determined through UV-DRS, ranged from 3.33 eV in SnD1 to 3.47 eV in SnDTi2. The photocatalytic degradation of Congo Red dye under xenon lamp irradiation was quantitatively assessed; notably, SnD1 exhibited a 23% higher rate constant compared to SnD2, attributed to its smaller particle size and a 31% greater surface area. Doping with 4% Ti in Sn0.96Ti0.04O2 more than doubled the degradation rate compared to a 6% Ti doping in Sn0.94Ti0.06O2. Furthermore, the generation of hydroxyl radicals was significantly enhanced, showing an increase of approximately 220% for SnD1 and 80% for SnD2. The capability of these nanomaterials to reduce the chemical oxygen demand of industrial organic pollutants to within regulatory limits under solar irradiation was documented, with SnD1 maintaining its photocatalytic efficiency over seven cycles of reuse. In the photocatalytic degradation rate of Congo Red dye, which was 23% higher for SnD1 compared to SnD2, and the threefold increase in the degradation rate for SnDTi1 compared to SnDTi2. An economic assessment, based on electricity tariffs in Saudi Arabia, highlighted the cost-effectiveness of SnD1, which ranged from 26.93 to 30.36 USD per breakdown cost of the photodegradation process, showing it to be less costly than SnD2. Conversely, SnDTi1 was found to be more economical than SnDTi2, with costs ranging from 26.67 to 33.09 USD. Collectively, the results emphasize the outstanding photocatalytic performance and cost-efficiency of SnDs, reinforcing their potential as sustainable solutions for the treatment of industrial wastewater. Additionally, the antibacterial efficacy of these materials against a range of bacteria, yeast, and fungi was investigated and substantiated.

The effects of B2O3 on viscosities, structures and phase transitions of CaO–MgO–Al2O3–SiO2–MnO-(0-8.0 wt%)B2O3 slags were investigated in this work. From the viscosity experimental results, the slag viscosities declined and the Eη decreased from 205.19 to 175.95 kJ/mol with the addition of B2O3 in slags from 0 to 8.0 wt%. From the structure analysis by using FTIR and XPS, B2O3 entered into the silicate network to increase the slag polymerization degree, while the formation of simple two-dimensional BO3 trihedral units could significantly decline the symmetry and stability of the structure. The effects of decreasing the network stability and forming low-melting eutectics were more dominated than the effects of increasing the structure polymerization degree, which could reduce the slag viscosity. Furthermore, adding B2O3 could decrease the slag initial precipitation temperature and change the primary crystal phase of the slag from melilite to spinel. The comprehensive effects of reducing the slag structure stability and decreasing the influence of solid phase on viscosity eventually resulted in the improvement of the slag fluidity.

To better understand the variations in physical, mechanical, and electrical properties, (Ge2S8)100-xTex chalcogenide glasses have been synthesized. These glasses encompass a composition range of 0 ≤ x ≤ 12. The mechanical properties have been studied by determining the longitudinal (νL) and transverse (νT) ultrasonic velocities. A network structure evaluation with composition has been performed via parameters like coordination number (<Nr>), crosslinking density (DCL), glass transition temperature (Tg), etc. Also, the elastic parameters trend values have been associated with the decrease in the cohesive energy value of the system. An overall physical analysis of the Ge-S-Te systems reveals that the system's rigidity and the cross-linking density are decreasing. Within the temperature range of 300–420 K, the temperature dependency of the dark conductivity and photoconductivity has been investigated. The intensity-dependent photoconductivity is governed by a power law, with intensity (Iph = Gδ) with δ lying between 0.5 and 1. The photosensitivity values reveal that the glassy system may be suitable for applications in optoelectronic devices. A correlation among the parameters has been established by calculating elastic parameters and conductivity measurements and evaluating the network structure theoretically. The present efforts clarify the composition-structure dependence and relationship in the Ge-S-Te glass series.

The lightweight design and load-bearing capacity of underwater vehicles remain perennial focal points. Ceramic lattice structures (CLSs) offer significant weight reduction while maximizing structural strength; however, their inherent brittleness poses a limitation. To optimize the performance of CLSs for underwater vehicle applications, a biomimetic Al2O3/phenol-formaldehyde (PF) resin composite structure (APCS) was proposed and fabricated by infiltrating additive-manufactured Al2O3 lattice structures (ALSs) with PF. Comprehensive assessments of the quasi-static mechanical properties were conducted using both experimental and simulation methods. The specific compressive strength and specific energy absorption of the APCSs under quasi-static compressive loading exhibited remarkable improvements, with the maximum values achieved from the body-centered cubic (BCC)/PF structure increasing by ∼15.23 and ∼307.93 times, respectively. In contrast to ALSs, the failure process of APCSs was gradual, with the confining pressure introduced by the PF promoting transverse crack propagation and layer-by-layer failure, thereby strengthening the ceramic lattice. Toughing mechanisms (i.e., crack arrest, crack deflection, and branching) were also observed in the APCSs. Furthermore, the simulation results aligned well with the experimental results, providing an in-depth analysis of internal damage and crack propagation. The improvements introduced by the composite structure in this study provide a reliable approach for obtaining lightweight and strong materials, thereby accelerating the application of ceramic-based materials in underwater vehicles.