Application of carbon nanomaterials (CNMs) in agricultural production has piqued the interest of researchers. However, despite the enormous importance of CNMs in plant development, little is known about the effects of carbon nanoparticle (CNP) doses on plant physiological responses. Therefore, the aim of the current study was to check the effects of nanostructured carbon derived from oil fly ash (COFA), which was derived for the first time from high-energy ball-milling followed by a sonication process, on Phaseolus vulgaris L. and Cicer arietinum L. plants. We evaluated the plant physiological and biochemical parameters of the COFA-treated seedlings. Two different doses (4 mg L⁻¹ and 8 mg L⁻¹) of COFA and a control were studied. The results indicated that the germination rate (%), shoot length, root length, pod length, leaf area, fresh weight and dry weight were increased with the addition of COFA. Likewise, COFA increased the contents of chlorophyll pigments (Chla, Chlb, carotenoids), proteins, and carbohydrates in both species compared to the control. Finally, these findings showed that a COFA treatment at 4 mg L⁻¹ after ball milled-sonication in water (BMW4) constituted the best dose for growth and physiology. Our findings reveal that the novel strategy of COFA engineering led to a boost in the growth of Phaseolus vulgaris and Cicer arietinum. Our results have high potential for agricultural research and provide an impact on food security.

Climate change is considered one of the major contributing factors to soil salinization, leading to land degradation. Several alternative organic waste materials are proposed for agricultural sustainability. Strawberry (Fragaria ananassa cv. Tioga) is one of the most consumed crop plants on a global scale due to its numerous economic and industrial benefits. Therefore, the purpose of this study was to understand how varying concentrations of diluted salt water (0%, 10%, 40%, 80%, 100%) affected the growth and physiology of Fragaria ananassa cv. Tioga. Our results indicated that shoot fresh weight (SFW), shoot dry weight (SDW), root fresh weight (RFW), root dry weight (RDW), leaf area, fruits weight, fruits per plants, relative water content (RWC), chlorophyll a and b significantly decreased in salt-stressed strawberry plants as compared to control plants. Moreover, salinity stress increased the malondialdehyde (MDA), hydrogen peroxide (H₂O₂), sodium (Na) content, SOD and APX activity. However, the application of dry waster of tea leaves (DWT) and dry waste of rose petals (DWR) led to improvements in chlorophyll content, RWC and potassium (K) content, antioxidant enzymes activity, and fruit yield of strawberry plants. In comparison to DWT, the best outcome was observed in plants treated with DWR, suggesting a new and eco-friendly strategy to increase crop yields under salt stress in commercial production. In conclusion, DWT and DWR treatments helps in the improvement of strawberries grown under salt stress conditions and increases their tolerance to salt stress.

The valorisation of waste from rose-based industrial products produces value-added substances and paves the way for advanced composites. The rose waste generated from the essential oil industry of the Taif rose (Rosa damascena trigintipetala Dieck) is significant, and its management or disposal is a source of concern. In this study, it was valorised to produce a value-added nanomaterial. The synthesis of biochar nanoparticles via high-energy ball milling has gained tremendous research interest in recent times because of its low cost and eco-friendliness. Ball milling is a solvent-free technology with strong potential for waste volatilisation and eco-sustainability through the production of engineered biochar nanoparticles. Different biochar samples were produced and characterised to harness the synergistic combination of biochar production and ball milling. They were prepared at a constant pyrolysis temperature of 300 °C by varying the pyrolysis times for 2 h, 5 h, and 10 h. The characterisation results showed that pyrolysis confirms a high content of carbon, minerals, graphitic structure, novel morphology and chemical characteristics attached to the biochar surface controlled by different pyrolysis durations. These properties were further enhanced by ball milling for 10 h. The results showed that ball milling enhanced the porosity, surface area, surface functional groups, visible light absorption, crystallinity, and carbon content, and these were accompanied by a reduction in the particle size and mineral impurities. The engineered biochar can be an important tool, with promising potential in novel composites for water purification and energy harvesting.

Steel slag waste produced by the steel industry accumulates in open areas or is disposed of in landfills, causing harm to the environment and human health. Valorizing steel slag through comprehensive data analysis is imperative and could add value to the product with respect to energy conversion and storage applications. This study investigated the morphological, structural, and optical characteristics of a thermally annealed steel slag composite generated from iron and steel factories. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, and UV–visible spectrophotometry were subsequently used to evaluate the impact of thermal treatment on the morphology, structure, elemental composition, and optical properties. It was found that the pre-treated slag composites contained a variety of irregular grain sizes and microscale fragments, primarily composed of C (18.55%), O (50.85%), and Fe (29.41%), with lower amounts of Mg (0.31%), Si (0.44%), and Ca (0.44%), indicating the natural formation of a disordered iron composite. Thermal treatment at different temperatures (300 °C, 600 °C, and 900 °C) increased the grain density and clustering, resulting in denser two-dimensional microstructures at 900 °C. Additionally, XRD and Raman analyses of both untreated and thermally treated slag composites revealed the presence of a disordered iron oxide composite, including (Fe₃O₄), hematite (α-Fe₂O₃), and maghemite (γ-Fe₂O₃) phases. A significant increase in optical absorbance was also observed after annealing at 600 °C, highlighting the successful optimization of the elemental composition of the slag composite. A band gap energy of approximately 2.2 eV was obtained from this optimization at 600 °C. The optical conductivity of the composite reached 2.1 × 10⁶ S⁻¹ at 600 °C, which indicates an enhancement in charge transfer among the optimized chemical elements in the waste composite. These findings suggest an optimization method for novel composites derived from steel slag waste, indicating its potential as a low-cost material for energy storage systems (batteries, supercapacitors, and fuel cells) and optoelectronic devices.

Model photocatalysts composed of titanium dioxide (TiO2) nanoparticles were prepared to assess the impact of different synthesis techniques on their photocatalytic activity towards methylene blue. TiO2 nanoparticles were synthesized using three distinct methods: high-energy ball-milling (HEBM), sonication, and pulse laser ablation. The engineered photocatalysts exhibited varying morphology, crystallinity, and optical properties, as evidenced by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The synthesis techniques notably resulted in different particle sizes, with mean sizes of 121.2 nm, 25.53 nm, and 22.38 nm, and corresponding crystallite sizes of 24.86 nm, 33.5 nm, and 34.4 nm for HEBM, sonication, and pulse laser ablation, respectively. All of the synthesized TiO2 nanoparticles displayed significantly enhanced photocatalytic activity under low-intensity UV light in comparison to the TiO2 raw material. However, the choice of synthesis method had a substantial impact on photocatalytic performance. Specifically, TiO2 prepared via ultrasonication and continuous ball milling exhibited the highest photocatalytic activity among the methods. The most rapid degradation rate (K = 0.0049 min^(-1)) was observed for TiO2 produced through continuous ball milling and ultrasonication. These findings indicate that the synthesized TiO2 nanoparticles hold potential for use as catalysts for degrading various types of organic pollutants.