The use of concentrated solar energy in processing ceramic materials is an attractive route to obtain these materials with low CO₂ emissions. In this work, nanostructures of monoclinic zirconia (m-ZrO₂) were obtained using concentrated solar energy provided by the IER-UNAM solar furnace as a heat source. In the first stage of the process, a Zr/O/C complex was obtained by sol-gel method at a temperature of 120 °C using zirconium n-propoxide and sorbitol as precursors reagents. This complex was used in a second stage to obtain m-ZrO₂ by heating it at a temperature of 1200 °C for one hour in air atmosphere. This last stage was performed in a solar furnace. Samples were analyzed by characterization techniques: FT-IR, TGA/DSC, XRD, TEM, and SEM confirming the formation of nanostructures of zirconia in monoclinic phase.

Hafnium carbide (HfC) ceramics are of growing interest due to their exceptional mechanical properties and ultra-high melting points, making them ideal for extreme environmental applications. In this study, we present a synthesis route for HfC nanoparticles via carbothermal reduction of an organic–inorganic hybrid precursor derived from hafnium tetrachloride (HfCl₄) and pectin, followed by thermal treatment at 1500 °C for 1.5 h under an argon atmosphere. According to TGA/DSC analysis of the hybrid precursor, hafnia phases initially formed during pyrolysis and were subsequently converted into HfC at 1500 °C, with the endothermic carbothermal reduction reaction initiating near 1200 °C. Comprehensive characterization using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD) with Rietveld refinement, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the synthesis of hafnium carbide (HfC) exhibiting predominantly cubic morphology. XRD analysis determined a lattice parameter of a = 4.63 Å and an interplanar spacing of d = 2.68 Å. Rietveld refinement revealed a phase composition of 98.08% HfC and 1.92% monoclinic hafnium dioxide (m-HfO₂). Debye–Scherrer analysis indicated an average crystallite size of 67.6 nm. SEM and TEM images showed uniformly distributed nanoparticles with an average particle size of approximately 65–70 nm.

Rod-like zirconium diboride (ZrB ₂ ) was synthesized for the first time using concentrated solar energy. The process involved the preparation of a Zr/O/C/B complex by sol–gel preparation at 120 °C, followed by carbothermic reduction in a quartz-windowed solar reactor under an argon atmosphere at 1300 °C for 25 min. The structural, morphological, and thermal properties of the resulting ZrB ₂ were investigated by FTIR, XRD, SEM, TEM, and TGA/DSC. Phase transformations of the precursor at 1100, 1200, and 1300 °C confirmed the formation of hexagonal ZrB ₂ with minor zirconia residues. The final product exhibited nanorod morphology with well-defined crystal growth along the (001) plane and crystal size of 56.1 nm. These results highlight the effectiveness of concentrated solar energy in promoting the rapid and sustainable synthesis of advanced ceramics and demonstrate its potential for large-scale nanomaterial production.