Plant growth-promoting rhizobacteria (PGPR) can promote plant growth and induce systemic resistance to biological and abiotic stresses. However, do all PGPR have significant effects in arid environments, and which PGPR have the most optimal effects? This study used a pot experiment to investigate the effects of inoculation with two different PGPR on the physiological and ecological characteristics of walnut (Juglans regia) seedlings under drought stress: Bacillus subtilis GE1, which secretes protease only, and Pseudomonas brassicacearum X123, which secretes protease and indoleacetic acid (IAA). The leaves inoculated with X123 under drought stress had higher net photosynthetic rate (P_n), transpiration rate (T_r), and stomatal conductance (g_s), especially stomatal length and stomatal width, compared to GE1 inoculation under drought stress. Moreover, inoculation with X123 significantly increased the leaf superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities by 20.84% and 12.41%, respectively, and the gibberellin (GA) and zeatin (ZT) contents by 72.07% and 19.17%, respectively, whereas the leaf soluble sugar and soluble protein contents significantly decreased compared with GE1 inoculation. These results indicated that the effects of GE1 inoculation on the physiological and ecological characteristics of walnut seedling leaves were significantly weaker in comparison with X123 inoculation as a result of its functional characteristics. The application of different PGPR on the drought tolerance of J. regia showed significant differences. Therefore, the selection of appropriate PGPR is key to achieving positive treatment effects under drought conditions.

A non-equilibrium ultrasound-assisted solid–liquid extraction method was developed for the separation of boron (B) in different forms (water-soluble B in the sap and structural B in the cells) in plant and phyto food samples. The factors influencing separation efficiency of the proposed method were investigated. The results showed that the method could be successfully applied to the separation of water-soluble and structural B within plant samples. The linear range of the method was in the range of 5–100 mg kg⁻¹ for different plant and phyto food samples. The limit of detection was 2 mg kg⁻¹ with a correlation coefficient of 0.998, and a relative standard deviation of 2.3%. This method has the advantage of only requiring a single plant sample for combined analysis of water-soluble and structural B. The B mass distribution of the two phases in different tissues obtained by the method is valuable for the elucidation of the molecular mechanisms in uptake of B in plants and phyto foods.

A novel composite material comprising titanium dioxide and layered double hydroxides (TiO₂/LDHs) was innovatively proposed and prepared using the co-precipitation method to overcome the shortcomings of titanium dioxide, such as low efficiency in separating electron–hole pairs induced by light and a low utilization rate of visible light. This material was used to study the visible-light-driven photocatalytic degradation of methylene blue. The experimental results show that by constructing efficient heterojunction structures through the alignment of interface band energies and regulating the interface charge transfer pathways, the recombination rate of photogenerated electron–hole pairs is significantly reduced, and the photocatalytic activity is greatly enhanced. Among the tested samples, the TiO₂/LDHs composite material with an aluminum-to-titanium molar ratio of 1:1 (AT11) demonstrated the best photocatalytic performance. Within 70 min of simulated sunlight exposure, the degradation rate of methylene blue reached 98.2%, and the optimal concentration of the catalyst was 1 g/L. The photocatalytic process follows a first-order kinetic model. After four cycles of use, the degradation efficiency of methylene blue by the AT11 composite material was 78.93%, demonstrating good stability. The free radical capture experiments indicated that the main active substances for the photocatalytic degradation of methylene blue were h⁺ and ·OH. The constructed TiO₂/LDHs heterostructure system significantly enhanced the photocatalytic performance of TiO₂ materials, which was conducive to the efficient utilization of solar energy.

TiO2/LDHs composites were synthesized in different proportions using the co-precipitation method. Their structural characteristics, morphological characteristics and spectral responses were characterized by means of X-ray diffraction (XRD), raman spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy. The photocatalytic performance of TiO2/LDHs were tested with the degradation of methylene blue. The photocatalytic light source selected is simulated sunlight (300-watt xenon lamp). Experimental results demonstrate that constructing a robust heterojunction through precise interface band alignment significantly suppresses photogenerated electron-hole recombination. Controlled charge transfer pathways at the interface further enhance photocatalytic degradation efficiency. Among the tested catalysts, AT11 (Al:Ti=1:1, molar ratio ) exhibits the highest photocatalytic activity, degrading 98.2% of methylene blue within 70 minutes under simulated solar irradiation. The degradation process follows first-order kinetics and maintains stable performance over four reuse cycles. Radical trapping experiments identify h⁺ and ·OH as the dominant active species responsible for dye degradation. This TiO₂/LDHs heterostructure significantly enhances TiO₂’s photocatalytic efficiency, enabling efficient solar energy utilization.

Nanoscale zero-valent iron (nZVI) exhibits great potential in the field of organic pollutant remediation due to its strong reducibility, high specific surface area and unique core–shell structure. However, pristine nZVI has inherent drawbacks including severe particle aggregation, surface passivation and poor electron selectivity, which greatly restrict its practical remediation performance. To improve the reactivity of nZVI, researchers have developed multiple modification approaches that significantly improve the dispersibility, stability and reactivity of nZVI. This review summarizes the main nZVI modification strategies, including metal modification, surface coating, carrier loading, sulfidation modification and biological integration. The advantages and limitations of each modification method are compared. Furthermore, the underlying removal mechanisms of modified nZVI toward typical organic pollutants are elaborated, covering direct reduction, advanced oxidation and synergistic degradation pathways. Key factors governing the degradation efficiency of modified nZVI are subsequently analyzed. Finally, existing bottlenecks for practical implementation and future research perspectives are proposed.