In this work, a simple and green synthesis procedure for phytofabrication Zinc oxide-silver supported biochar nanocomposite (Ag/ZnO@BC) via Persicaria salicifolia biomass is investigated for the first time to uphold numerous green chemistry such as less hazardous chemical syntheses. XRD technique showed the crystal structure of the phytosynthesized Ag/ZnO@BC, whereas UV–visible spectroscopy, FT-IR, SEM, EDX, TEM, and XPS analyses indicated the successful biosynthesis of the nanocomposite. Testing the photocatalytic potential of this novel nanocomposite in the removal of TC under different conditions unraveled its powerful photodegradation efficiency that reached 70.3% under the optimum reaction conditions: TC concentration; 50 ppm, pH; 6, a dose of Ag/ZnO@BC; 0.01 g, temperature; 25 °C, and H₂O₂ concentration; 100 mM. The reusability of Ag/ZnO@BC was evident as it reached 53% after six cycles of regeneration. Ag/ZnO@BC was also shown to be a potent antimicrobial agent against Klebsiella pneumonia as well as a promising antioxidant material. Therefore, the current work presented a novel nanocomposite that could be efficiently employed in various environmental and medical applications.

Degradation of organic contaminants into less toxic substances is the best option to remove these compounds rather than using conventional techniques. The sulfate radical-based-advanced oxidation process is an effective strategy that degrades organic contaminants by activating peroxymonosulfate (PMS). Such a strategy generates singlet oxygen (¹O₂), hydroxyl ( $$^ \bullet \!{{{\mathrm{OH}}}}$$∙OH ), and sulfate ( $${{{\mathrm{SO}}}}_4^{ \bullet\! - }$$SO4∙− ) radicals. $${{{\mathrm{SO}}}}_4^{ \bullet \!- }$$SO4∙− is distinguished by its high oxidation selectivity and activity toward the degradation of organic contaminates compared to other radicals. Various catalysts are employed in PMS activation including layered doubled hydroxides (LDHs), which are characterized by their facile synthesis and high catalytic activity. This review article is the first attempt to compile the recent progress in the degradation of common organic pollutants including aromatic compounds, pharmaceutical residues, and dyes via the PMS activation using LDH-based catalysts. The degradation pathways, reaction parameters’ influence, stability of LDHs, and comparisons between different LDH-based catalysts are investigated in this work.

The conventional synthesis of nanomaterials employing physical and chemical methods usually requires high cost and toxic chemicals. Thus, a facile, ecofriendly, cost-effective, novel, and sustainable route for the synthesis of a silver-loaded biochar nanocomposite ([email protected]) using Chenopodium ambrosioides leaf extract and biomass is reported for the first time in this study to advocate many of the principles of green chemistry such as safer solvents and auxiliaries. UV spectroscopic analysis at 420 nm indicated the formation of silver nanoparticles (AgNPs). The band gap energy of [email protected] was 1.9 eV, confirming its potential use as a photocatalyst. [email protected] was found to be photoluminescent at 425 nm. AgNPs on the surface of biochar were predominantly spherical with a size range of 25–35 nm and a surface area of 47.61 m²/g. A zeta potential of −5.87 mV designated the stability of [email protected] Testing the photocatalytic potential of [email protected] to remove methylene blue from wastewater demonstrated its high removal efficiency that reached 88.4% due to its high efficiency of electron transfer confirmed via electrochemical impedance spectroscopy analysis and retained 70.65% after six cycles of reuse. [email protected] was shown to be a powerful broad-spectrum antimicrobial agent as it completely prevented the growth of Escherichia coli and also inhibited the growth of Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis, and Candida albicans with the inhibition zones of 19, 18, 22, and 16 mm, respectively.

In the current study, a facile, rapid, and ecologically safe photosynthesis of gold nanoparticles (AuNPs) that remained stable for 3 months is reported to advocate the main aspects of green chemistry, such as safer solvents and auxiliaries, and the use of renewable feedstock. Zi-AuNPs were phytosynthesized by the aqueous extract of Ziziphus spina-christi leaves, and numerous techniques were employed for their characterization. The results demonstrated the successful phytofabrication of crystalline AuNPs with brownish-black color, spherical nanoparticles with a size between 0 and 10 nm, a plasmon peak at 540 nm, and a surface charge of −25.7 mV. Zi-AuNPs showed an effective photodegradation efficiency (81.14%) against malachite green and a good recycling capacity of 69.2% after five cycles of regeneration. The cytotoxicity test by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay signified a high anticancer efficiency for both Zi-AuNPs and Z. spina-christi extract against human breast cancer cells (MCF7 cell line) with IC₅₀’s of 48 and 40.25 μg/mL, respectively. Highly efficient antioxidant capabilities were proven with 2,2-diphenyl-1-picrylhydrazyl (DPPH) removal percentages of 67.5% for Zi-AuNPs and 92.34% for Z. spina-christi extract.