Samples of the bimetallic-based NH₂-MIL-125(Ti) at a ratio of Mⁿ⁺/Ti⁴⁺ is 0.15 (Mⁿ⁺: Ni²⁺, Co²⁺ and Fe³⁺) were first synthesized using the solvothermal method. Their fundamental properties were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectra, scanning electron microscopy (SEM), N₂ adsorption–desorption measurements, and UV–Vis diffuse reflectance spectroscopy (UV-Vis DRS). The as-acquired materials were used as high-efficiency heterogeneous photocatalysts to remove Rhodamine B (RhB) dye under visible light. The results verified that 82.4% of the RhB (3 × 10⁻⁵ M) was degraded within 120 min by 15% Fe/Ti−MOFs. Furthermore, in the purpose of degrading Rhodamine B (RhB), the rate constant for the 15% Fe/Ti-MOFs was found to be 2.6 times as fast as that of NH₂-MIL-125(Ti). Moreover, the 15% Fe/Ti-MOFs photocatalysts remained stable after three consecutive cycles. The trapping test demonstrated that the major active species in the degradation of the RhB process were hydroxyl radicals (HO^∙) and holes (h⁺).

Co-doped Fe-MOF bimetallic organic framework materials at different ratios were synthesized based on the solvothermal method, and we evaluated their morphological characteristics by modern analytical methods such as SEM, XRD, FT-IR, and isotherm of nitrogen adsorption-desorption (BET). The specific surface area of the 0.3 CoFe-MOF sample (280.9 m²/g) is much larger than the Fe-MOF and samples at other ratios. The post-synthesized materials were evaluated for their ability to absorb various dyes, including Methylene Blue (MB), Methyl orange (MO), Congo red (CR), and Rhodamine (RhB), and evaluated for the effects of pH, the initial concentration of the dye solution, time, and dose of adsorbent. The results show that the 0.3 CoFe-MOF material has a high adsorption capacity that is superior to both the original Fe-MOF and the CoFe-MOFs at other ratios. The highest adsorption capacity of MB dye by 0.3 CoFe-MOF reaches up to 562.1 mg/g at pH 10, the initial concentration of MB of 200 mg/L, after 90 min. The charged properties of the dyes and the charged nature of the bimetallic organic frameworks are best demonstrated through the adsorption of dye mixtures. The adsorption efficiency on the mixed system of cationic (MB) and anionic (MO) dyes yielded the highest removal efficiency of 70% and 81%, respectively, after 30 min. Therefore, the research has opened up the potential application of M/Fe-MOF modified materials and CoFe-MOF in organic dyes adsorption in wastewater treatment for environmental protection.

Removing antibiotics from water is critical to prevent the emergence and spread of antibiotic resistance, protect ecosystems, and maintain the effectiveness of these vital medications. The combination of ozone and electrocoagulation in wastewater treatment provides enhanced removal of contaminants, improved disinfection efficiency, and increased overall treatment effectiveness. In this work, the removal of sulfamethoxazole (SMX) from an aqueous solution using an ozone–electrocoagulation (O–EC) system was optimized and modeled. The experiments were designed according to the central composite design. The parameters, including current density, reaction time, pH, and ozone dose affecting the SMX removal efficiency of the OEC system, were optimized using a response surface methodology. The results show that the removal process was accurately predicted by the quadric model. The numerical optimization results show that the optimum conditions were a current density of 33.2 A/m², a time of 37.8 min, pH of 8.4, and an ozone dose of 0.7 g/h. Under these conditions, the removal efficiency reached 99.65%. A three-layer artificial neural network (ANN) with logsig-purelin transfer functions was used to model the removal process. The data predicted by the ANN model matched well to the experimental data. The calculation of the relative importance showed that pH was the most influential factor, followed by current density, ozone dose, and time. The kinetics of the SMX removal process followed the first-order kinetic model with a rate constant of 0.12 (min⁻¹). The removal mechanism involves various processes such as oxidation and reduction on the surface of electrodes, the reaction between ozone and ferrous ions, degradation of SMX molecules, formation of flocs, and adsorption of species on the flocs. The results obtained in this work indicate that the O–EC system is a potential approach for the removal of antibiotics from water.

For the first time, activated carbon from a durian shell (ACDS) activated by H₂SO₄ was successfully synthesized in the present study. The fabricated ACDS has a porous surface with a specific surface area of 348.0017 m²·g⁻¹, average capillary volume of 0.153518 cm³·g⁻¹, the average pore diameter of 4.3800 nm; ash level of 55.63%; humidity of 4.74%; density of 0.83 g·cm⁻³; an iodine index of 634 mg·g⁻¹; and an isoelectric point of 6.03. Several factors affecting Methylene Blue (MB) adsorption capacity of ACDS activated carbon was investigated by the static adsorption method, revealing that the adsorption equilibrium was achieved after 90 min. The best adsorbent pH for MB is 7 and the mass/volume ratio is equal to 2.5 g·L⁻¹. The MB adsorption process of ACDS activated carbon follows the Langmuir, Freundlich, Tempkin, and Elovich isotherm adsorption model, which has determined the maximum adsorption capacity for MB of ACDS as q_max = 57.47 mg·g⁻¹. The MB adsorption process of ACDS follows the of pseudo-second-order adsorption kinetic equation. The Weber and Morris Internal Diffusion Model, the Hameed and Daud External Diffusion Model of liquids have been studied to see if the surface phase plays any role in the adsorption process. The results of thermodynamic calculation of the adsorption process show that the adsorption process is dominated by chemical adsorption and endothermic. The obtained results provide an insight for potential applications of ACDS in the treatment of water contaminated by dyes.

${\mathrm{TiO}}_2$-based photocatalysts still have some limitations such as large bandgap and low surface area, leading to low efficiency in the photocatalytic degradation of VOCs and limiting it to use in sunlight. Here we report that the nanostructured Ir-doped TiO₂ as an efficient photocatalyst generates an excellent risk-reduction material of gaseous toluene. We have succeeded in developing a nanostructured Ir-doped ${\mathrm{TiO}}_2$ and initially found that excellent efficient photocatalytic VOC decomposition can be achieved in our materials The nanostructured Ir-doped ${\mathrm{TiO}}_2$ was synthesized by a one pot, low temperature hydrothermal process with different ratios of Ir doped into the ${\mathrm{TiO}}_2$. It exhibited a high surface area, uniformly spherical morphology of 10–15 nm. Its activity for the photocatalytic degradation of gaseous toluene exhibited up to 97.5% under UV light. This enhancement could be explained by iridium doping which created a high concentration oxygen vacancy and changed the recombination rate of the photogenerated charge carriers. More generally, our study indicates a strategic way to develop the novel nanostructured material for numerous applications.

A CuO-loaded SrTiO₃ catalyst showed highly photocatalytic activity for H₂ evolution. This catalyst was prepared by an impregnation method and characterized by XRD, TEM, BET, XPS, Uv-vis DRS and PL techniques. Under optimum conditions, the best rate of H₂ evolution of the CuO-loaded SrTiO₃ catalyst is 5811 µmol h⁻¹g⁻¹, whereas it is a mere 34 µmol h⁻¹g⁻¹ for the pure SrTiO₃. High efficiency, low cost and good stability are some of the merits that underline the promising potential of CuO-loaded SrTiO₃ in the photocatalytic hydrogen.