In this article a facile and green procedure for the synthesis of novel calcium silicate hydrated-nylon 6/66 nanocomposites is proposed. Calcium silicate hydrate (CSH) was synthesized by a hydrolysis technique assisted by ultrasound and using sodium dodecyl sulphate (SDS) as surfactant. CSH-nylon 6/66 nanocomposites were obtained by a solution mixing method at CSH loadings of 2.5, 25, 50 and 75 weight percent (samples CA, CD, CB and CC, respectively). The synthesis of CSH was confirmed by DRX and ATR-FTIR techniques; the CSH sample presents as mesoporous with a diameter between 3.34 nm and 52.68 nm and an average size of 27.07 nm; the specific surface area of the CSH sample was 343.99 m² g⁻¹. The formation of the CSH-nylon 6/66 nanocomposites was confirmed by ATR-FTIR, SEM, XRD, TGA, DSC and XPS techniques. The crystallization and melting temperatures (T_m and T_c, respectively) of CSH-nylon 6/66 nanocomposites occur at a slightly lower temperatures than those of neat Ny 6/66. These results suggest a slight decrease of the crystallite size and crystallization rate of nylon 6/66. The fusion enthalpy (ΔH_f) decreases with increase in CSH content in nylon 6/66, which can be associated to a good dispersion. The XRD peaks of the nylon 6/66 at 19.99° and 23.77° were displaced at slightly higher values of 2θ with the incorporation of CSH in the polymer forming nanocomposite materials.

In this work, we reported obtaining mesoporous Bi-doped TiO₂ by mechanosynthesis and bismuth loading of 0%, 1%, 3%, 5%, and 10% (milled TiO₂, TiO₂ Bi 1%, TiO₂ Bi 3% TiO₂ Bi 5%, and TiO₂ Bi 10%, respectively). The effect of bismuth doping and ball milling on the crystal structure, optical properties, and photocatalytic performance of Bi-doped TiO₂ mesoporous samples under UV, visible, and sun irradiation was investigated. According to the results of the Rietveld refinement, the estimated chemical formulas for the TiO₂ Bi 1%, TiO₂ Bi 3%, TiO₂ Bi 5%, and TiO₂ Bi10% samples were Ti_0.99Bi_0.01O₂, Ti_0.97Bi_0.03O₂, Ti_0.96Bi_0.04O₂, and Ti_0.91Bi_0.09O₂ respectively. The incorporation of Bi into the TiO₂ lattice causes the crystallite size to decrease and, consequently, the absorption spectrum of TiO₂ to extend into the visible region of the electromagnetic spectrum, resulting in a lower band gap (E_g) value. Bi-doped TiO₂ mesoporous samples had E_g values of 2.90 eV, 2.83 eV, 2.77 eV, and 2.70 eV for the TiO₂ Bi 1%, TiO₂ Bi 3%, TiO₂ Bi 5%, and TiO₂ Bi 10% samples, respectively. Photocatalytic removal of methylene blue (MB) data fit well for second-order kinetics. Photocatalytic activity increase followed the order of TiO₂ Bi 5% > TiO₂ Bi 10% > TiO₂ Bi 3% > TiO₂ Bi 1% > pristine TiO₂. The TiO₂ Bi 5% sample exhibited excellent photocatalytic performance for MB photodegradation under natural sunlight (89.2%).

Solar energy is one of the most promising and developed technologies in recent years, due to its high efficiency and low cost. Perovskite-type solar cells have been the focus of attention by the world scientific community. The main objective of this article is to present an (PSCs) analysis of the various investigations reported on the development of ABX3 inorganic halide perovskite-based solar cells, with emphasis in the effect that temperature and humidity have on their chemical and crystal structure stability. The main methods that are used to obtain ABX3 inorganic halide perovskites are also presented and analyzed. An analysis about the structure of these photovoltaic cells and how to improve their efficiency (PCS), fill factor (FF), short circuit current density (Jsc) and open circuit voltage (Voc) of these devices is presented. As a conclusion, a relationship of the methods, synthesis variables, and type of inorganic halide perovskite used for the development of devices with the best efficiencies is presented; the trends towards which this area of science is heading are also highlighted.

This research focused on the evaluation of the Fe₂O₃/TiO₂ composite and two industrial wastes, a kaolin (Clay-K) and a blast furnace sludge (BFS), as adsorbents and/or photocatalytic materials to enhance the removal of cyanide from aqueous solutions. Cyanide adsorption tests were conducted in the absence of light. In contrast, cyanide photodegradation tests were conducted under three types of irradiations: visible light, ultraviolet (UV) light, and natural sunlight. For the latter case, two irradiance conditions were evaluated. Cyanide adsorption from aqueous phases was similar for Clay-K and TiO₂/Fe₂O₃ materials, which adsorbed almost twice as much cyanide compared to the BFS sample. The differences observed in cyanide removal were explained in terms of the material’s surface area and chemical composition, and a complexation of cyanide ions with surface metals was suggested as the most feasible adsorption mechanism. The set of cyanide photodegradation experiments promoted, in general, higher cyanide removal from the aqueous solution compared to the adsorption processes. Under the conditions used in this study and when using Clay-K and BFS as promoters, cyanide photodegradation progressively enhanced with the following radiations: visible light < UV light ~ UV+solar ≤ Visible+solar. In the case of the TiO₂/Fe₂O₃ composite, cyanide photodegradation increased in the following order: UV light < visible light < UV+solar ~ Visible+solar. Clearly, solar radiation had a significant effect on promoting cyanide removal. For experiments conducted with natural sunlight, the set with irradiance of 600–800 W/m² exhibited the highest cyanide removal percentage, and the BFS had the best performance among the three tested samples over a period of 2 h. Results showed the benefit of using industrial wastes to remove cyanide from aqueous solutions and illustrates remediation of industrial effluents is potentially feasible within the framework of a circular economy.

The interest in multifunctional biomaterials to be implanted are also able to release drugs that reduce pain and inflammation or prevent a possible infection has increased. Bioactive materials such as silica (SiO₂) containing surface silanol groups contribute to the nucleation and growth of hydroxyapatite (HAp) in a physiological environment. Regarding biocompatibility, the spherical shape of particles is the desirable one, since it does not cause mechanical damage to the cell membrane. In this work, the synthesis of SiO₂ microspheres was performed by the modified Stöber method and they were used for the biomimetic growth of HAp on their surface. The effect of the type of surfactant (sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB), and polyethylene glycol (PEG)), and heat treatment on the morphology and size of SiO₂ particles was investigated. Monodisperse, spherical-shaped SiO₂ microparticles with an average particle size of 179 nm, were obtained when using PEG (SiO₂-PEG). The biomimetic growth of HAp was performed on this sample to improve its biocompatibility and drug-loading capacity using gentamicin as a model drug. Biomimetic growth of HAp was confirmed by FTIR-ATR, SEM-EDX and TEM techniques. SiO₂-PEG/HAp sample had a better biocompatibility in vitro and gentamicin loading capacity than SiO₂-PEG sample.

This research is mainly focused on the evaluation of TiO2/Fe2O3 composite and two industrial types of waste (kaolin (Clay-K) and a blast furnace sludge (BFS)) as adsorbent materials of cyanide and as photocatalysts. First, adsorption tests were performed in the absence of light. During photodegradation experiments, the effect of the type of irradiation (ultraviolet (UV) light), visible light and natural sunlight), irradiation time, the type of photocatalyst, as well as irradiance in case of natural sunlight use, were investigated. Adsorption results indicate that Clay-K and TiO2/Fe2O3 materials adsorb approximately twice as much cyanide compared to the BFS sample, which only adsorbs 33.3% (124.87 mg/g); this is due to its smaller specific surface area (5.69 m2/g) compared to that of the other two materials (Clay-K and TiO2/Fe2O3 (14.93 m2/g and 66.59 m2/g, respectively). The results obtained from the study of photodegradation of cyanide under UV irradiation, indicate that Clay-K and BFS samples photodegrade cyanide by 96.44% and 92.66%, respectively. On the other hand, using UV irradiation plus solar irradiation and visible plus solar irradiation, the best photocatalyst was the TiO2/Fe2O3, with 98.66% photodegradation. The use of natural sunlight (irradiance of 600 to 800 W/m2) of a NaCN solution of 750 mg/L, the BFS material was the most efficient to photodegrade cyanide, obtaining 97% in two hours and 87% in just 30 minutes of irradiation.