This work reports the synthesis, characterization, and photocatalytic performance of multifunctional spheres based on AgNP-doped TiO₂-Fe₃O₄ embedded in an alginate–chitosan biopolymeric matrix for the removal of organic contaminants from water. The composite powders exhibited a nanocrystalline structure composed of anatase TiO₂ (~20 nm) and magnetite (~25 nm), with homogeneously dispersed Ag nanoparticles, as observed by SEM. The spheres presented a mainly submicrometric particle size distribution (0.55–0.92 µm), favoring high surface area and colloidal stability. Under simulated solar irradiation, the material achieved efficient photocatalytic degradation of methylene blue, with a pseudo-first-order rate constant of 0.112 h⁻¹ and ~46% decolorization after 5 h. UV-Vis spectra showed progressive attenuation of the dye absorption band without accumulation of intermediates. Magnetic recovery tests confirmed rapid separation and reuse without performance loss. The enhanced activity is attributed to the synergistic interaction among plasmonic Ag, photocatalytic TiO₂, redox-active Fe₃O₄, and the adsorptive carbon–biopolymer matrix. The material exhibited strong antibacterial activity, achieving over 90% removal of fecal coliforms after 5 h of irradiation. Therefore, the developed AgNP-doped TiO₂-Fe₃O₄ spheres represent a sustainable, reusable, and efficient material for solar-assisted water sanitation.

This work reports the synthesis, characterization, and photocatalytic performance of mul-tifunctional spheres based on AgNPs-doped TiO2-Fe3O4 embedded in an alginate-chitosan biopolymeric matrix for the removal of organic contaminants from water. The composite powders exhibited a nanocrystalline structure composed of anatase TiO2 (~20 nm) and magnetite (~25 nm), with homogeneously dispersed Ag nanoparticles, as observed by SEM. The spheres presented a mainly submicrometric particle size distribution (0.55-0.92 µm), favoring high surface area and colloidal stability. Under simulated solar irradiation, the material achieved efficient photocatalytic degradation of methylene blue, with a pseu-do-first-order rate constant of 0.112 h⁻¹ and ~46 % decolorization after 5 h. UV-Vis spectra showed progressive attenuation of the dye absorption band without accumulation of in-termediates. The spheres also exhibited strong antibacterial activity, reaching 87 % reduc-tion of total coliforms and >93 % of fecal coliforms after 5 h of irradiation. Magnetic recov-ery tests confirmed rapid separation and reuse without performance loss. The enhanced activity is attributed to the synergistic interaction among plasmonic Ag, photocatalytic TiO2, redox-active Fe3O4, and the adsorptive carbon-biopolymer matrix. The material ex-hibited strong antibacterial activity, achieving over 90% removal of fecal coliforms after 5 h of irradiation Therefore, the developed AgNPs-doped TiO2-Fe3O4 spheres represent a sus-tainable, reusable and efficient material for solar-assisted water sanitation.

Multifunctional material systems increasingly combine several active phases, including photocatalysts, magnetic phases, adsorbents, controlled-release agents, and antimicrobial oxides, within a single encapsulating matrix. This paper presents an augmented reality and interactive 3D mobile app for visualizing a Multifunctional Hybrid Material (MHM-App) that provides a representation of a multifunctional sphere composed of titanium dioxide (TiO₂), magnetite (Fe₃O₄), activated carbon, hypochlorite-loaded clinoptilolite zeolite, and copper (Cu), encapsulated in a sodium alginate matrix formed by ionic gelation and coated with a crosslinked chitosan shell. The MHM-App provides two complementary visualization modes: an AR mode in which the sphere is anchored to a detected horizontal surface through raycasting, and a non-AR mode in which the same geometry is rendered in a virtual scene with a fixed-perspective camera and explicit lighting. We evaluated the user experience using the User Experience Questionnaire and its short version (UEQ and UEQ-S, respectively), obtaining an excellent overall score in the UEQ-S and in five of six categories of the UEQ (except the novelty category, with a “good” score), confirming that MHM-App is perceived as attractive, understandable, efficient, dependable, and stimulating. The MHM-App integrates augmented reality and interactive 3D visualization, enabling students and technical audiences to explore the spatial coexistence of multiple active phases and their functions within a single material structure, overcoming the limitations of conventional static diagrams and representing a technological approach to support scientific communication, interdisciplinary collaboration, education, and technical dissemination in materials science.

Multifunctional hybrid spheres were developed via ionic gelation, using sodium alginate as an encapsulating matrix to integrate TiO₂, Fe₃O₄, activated carbon, hypochlorite-impregnated clinoptilolite zeolite, and metallic copper, followed by chitosan coating and glutaraldehyde cross-linking to enhance mechanical stability. The material combines photocatalytic, adsorbent, antimicrobial, and magnetic functions in a single system, expected to support partial treatment of contaminated water. X-ray diffraction confirmed the expected crystalline phases with no impurities. Physicochemical evaluation showed reductions in turbidity (1.8 to 0.7 NTU), total hardness (306 to 150 mg/L), iron (0.4 to 0.01 mg/L), and lead (<0.001 mg/L), while free residual chlorine remained within permissible limits. Microbiologically, fecal coliforms decreased from 83 to <1.5 CFU/100 mL and total coliforms from 839 to 19 CFU/100 mL. Photocatalytic activity, evaluated using methylene blue, showed an absorbance decrease from 0.38 to 0.17 A.U. over 4 h, corresponding to a blank-corrected removal of 95.5% relative to clean water, fitted to a pseudo-first-order kinetic model (R² = 0.8868). These results demonstrate a synergistic effect among adsorption, photocatalysis, disinfection, and magnetic recovery, positioning the hybrid spheres as a promising alternative for sustainable water treatment technologies.