Salt stress obstructs plant’s growth by affecting metabolic processes, ion homeostasis and over-production of reactive oxygen species. In this regard silicon (Si) has been known to augment a plant’s antioxidant defense system to combat adverse effects of salinity stress. In order to quantify the Si-mediated salinity tolerance, we studied the role of Si (200 ppm) applied through rooting media on antioxidant battery system of barley genotypes; B-10008 (salt-tolerant) and B-14011 (salt-sensitive) subjected to salt stress (200 mM NaCl). A significant decline in the accumulation of shoot (35–74%) and root (30–85%) biomass was observed under salinity stress, while Si application through rooting media enhancing biomass accumulation of shoots (33–49%) and root (32–37%) under salinity stress. The over-accumulation reactive oxygen species i.e., hydrogen peroxide (H₂O₂) is an inevitable process resulting into lipid peroxidation, which was evident by enhanced malondialdehyde levels (13–67%) under salinity stress. These events activated a defense system, which was marked by higher levels of total soluble proteins and uplifted activities of antioxidants enzymatic (SOD, POD, CAT, GR and APX) and non-enzymatic (α-tocopherol, total phenolics, AsA, total glutathione, GSH, GSSG and proline) in roots and leaves under salinity stress. The Si application through rooting media further strengthened the salt stressed barley plant’s defense system by up-regulating the activities of enzymatic and non-enzymatic antioxidant in order to mitigate excessive H₂O₂ efficiently. The results revealed that although salt-tolerant genotype (B-10008) was best adopted to tolerate salt stress, comparably the response of salt-sensitive genotype (B-14011) was more prominent (accumulation of antioxidant) after application of Si through rooting media under salinity stress.

Water-stable zeolitic imidazolate frameworks (ZIF) with zinc and cobalt cations were synthesized to explore the effect of metal ions on arsenic adsorption. At room temperature (25 2 ºC) and pH 7.8, maximum adsorption capacities of arsenic (As5+) on the surface of ZIF-8 and ZIF-67 were 87.03 and 86.70 mg g-1 respectively, with encouraging results up to 95% reusability of the adsorbents. The results of this study revealed that electrostatic attraction and ion exchange were the major mechanisms responsible for better efficiencies for adsorptive removal of arsenic. The evidence for the adsorption of arsenic contaminants was confirmed by FTIR analyses. The pseudo second order and Langmuir models were best suited to explain the adsorption of arsenic species on the surface of the as-synthesized metal-organic frameworks (MOFs). Based on the results, it was possible to conclude that the metal atoms in the synthesized MOFs had a minor impact on adsorption, since these MOFs presented identical results in the removal of arsenic species. This observation can be explained by the presence of a similar organic linker (2-methyl imidazole), which points to almost the same geometry and sponginess. However, there was a slight difference in the adamsite (organo-arsenic) removal achieved by the MOFs with different metal atoms.

The development of an efficient catalyst to meet the world^'s increasing energy demand and eliminate organic pollutants in water, is a concern of current researchers. In this article, a highly effective composite has been synthesized using the solvothermal approach, by incorporating CuWO₄ nanoparticles into Fe-based MOF, Fe (BDC). The synthesized samples were analyzed further by some characterization techniques such as X-ray diffraction, Fourier transform infrared spectroscope (FTIR) and scanning electron microscopy. The highest catalytic activity for the oxygen evolution reaction was observed in the CuWO₄@MIL-101(Fe) composite, which exhibited low overpotential 188 mV to obtained the current density of 10 mA cm⁻², and a smaller Tafel slope of 40 mV dec⁻¹. The nanocomposite CuWO₄@MIL-101(Fe) material showed enhanced visible light absorption and maximum degradation of methylene blue up to 96.92 %. It has been found that this research promotes the development of an efficient MOF-based catalyst for OER and photocatalytic technology.

The primary aim of this study is to investigate the degradation efficacy of the Ppy/TiO₂-Fe photocatalyst for MB dye in an aqueous solution. Firstly, the direct addition of TiO₂ and Fe was done to prepare Ppy/TiO₂-Fe photocatalyst. Fourier transformation infrared spectroscopy, XRD, SEM, BET surface area analysis, and magnetization tests established the formation of the Ppy/TiO₂-Fe photocatalyst. The crystallite sizes of TiO₂, Fe-TiO₂, and Ppy/TiO₂-Fe photocatalyst were estimated to be 24.99 nm, 21.94 nm, and 21.84 nm, respectively. For the synthesis confirmation, the FTIR spectrum confirmed the existence of Ti-O, Fe-O, and Ppy-related bonds. While comparing the SEM images, the impact of polypyrrole on the particle shape was observed with less aggregation and increased surface roughness. The VSM analysis revealed that incorporating polypyrrole (Ppy) into Fe-TiO₂ significantly enhances its magnetic properties, with Ppy/TiO₂-Fe exhibiting superparamagnetic behavior, characterized by a higher saturation magnetization (M_s) of 33.11 emu/g and a lower coercivity (H_c) of 0.160 Oe, compared to Fe-TiO₂’s M_s of 1.09 emu/g and H_c of 341.39 Oe. The N₂ sorption desorption, with a specific surface area of 2.25 × 10² m²/g, is beneficial for photocatalytic activity. The concentration of dye, amount of catalyst, pH, and temperature were studied to evaluate the photocatalytic efficiency of the synthesized Ppy/TiO₂-Fe photocatalyst under different conditions. The findings revealed a degradation efficiency of 91.92%. The degradation rate reached 91.92% under optimal conditions within 120 min and could be fitted well by first-order kinetics. The photocatalytic efficiency was also evaluated for the scavenger, and the concentration of H₂O₂ and the reusability of the catalyst were demonstrated. Based on the observed results, the Ppy/TiO₂-Fe photocatalyst could be applied more effectively and efficiently to photocatalytic degradation of organic dyes in wastewater treatment.

A Ppy/Ag-ZnO catalyst was successfully synthesized at room temperature using a novel, green methodology. It involves a mechanically assisted metathesis reaction. The Ppy/Ag-ZnO catalyst was analyzed via X-ray diffraction Technique (XRD), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), UV–visible spectroscopy, Brunauer–Emmett–Teller (BET), and zeta potential. Debye Scherrer’s calculation suggested a crystallite size of 2.30 nm for Ppy/Ag-ZnO nanocomposite. SEM confirmed the production of aggregated particles with an average size of 2.65 μm, endorsing the -ve zeta potential value (−6.78 mV) due to the presence of Van der Waals forces among the particles of Ppy/Ag-ZnO. DSC confirms that the strong interfacial interaction between Ag-ZnO and the polar segments of Ppy is responsible for the higher Tg (107 °C) and Tm (270 °C) in Ppy/Ag-ZnO. The surface area and average pore size of Ppy/Ag-ZnO catalyst were determined to be 47.08 cm³/g and 21.72 Å, respectively. Methyl orange (MO) was used as a probe in a photocatalytic reaction of fabricated material, which demonstrated exceptional efficiency, exhibiting a removal rate of 91.11% with a rate constant of 0.028 min⁻¹. Photocatalytic degradation of MO was shown to follow pseudo-first-order kinetics.