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Expanding applications of metal-based nanoparticles (NPs) in industry and agriculture have influenced agro-ecosystems. However, relatively little is known about the bioaccumulation, distribution, and phytotoxicity of ZnO-NPs, CuO-NPs, ZnO-bulk, CuO-bulk, Zn2+, or Cu2+ in maize. Plants were exposed to 0.05-2 mg ml-1 or g-1 of six tested materials in agar (7 days) in hydroponic medium (20 days), or sandy-clay-loam soil (20 or 40 days). Seed germination, emergence and lengths of plumules, principal and seminal roots were significantly inhibited by ZnO-NPs, CuO-NPs, Zn2+, and Cu2+. Toxicity was more pronounced in hydroponic culture than in soil, and perceptible alterations in biomolecules were evident. ICP-MS analysis exhibited progressive uptake of metals while morphological, elemental, and surface/deeper scanning showed translocation and distribution of NPs in tissues. Tested materials induced enhanced superoxide radical production, lipid peroxidation, and antioxidant enzymes and proline levels. Exposure significantly reduced P-accumulation, photosynthesis, and protein production. Zn2+ and Cu2+ were found to be more toxic than NPs. Compared to 20 days exposure in soil, toxicity slightly increased after 40 days. ZnO-NPs and CuO-NPs increased apoptotic sub-G1 population by 22.4% and 38%, respectively. These results provide a better understanding of the mechanistic aspects responsible for the nanotoxicities of ZnO- and CuO-NPs in maize.

In the present work, CaWO4/Ag2MoO4 nanohybrid was synthesized by sono-chemical method. Fourier-transform infrared spectroscopy (FTIR), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDAX) and BET surface area analyzer were used to characterize the structure and optical properties of CaWO4/Ag2MoO4 nanohybrid. The HRTEM image represents the formation of CaWO4/Ag2MoO4 nanohybrid with clear facets and narrow size range. The XRD results showed that CaWO4/Ag2MoO4 nanohybrid composed of combined phases of CaWO4 and Ag2MoO4. A red-shift was observed in the optical absorption of nanohybrid after loading Ag2MoO4 on CaWO4. The photodegradation of MB by CaWO4/Ag2MoO4 nanohybrid (91.4%) showed excellent performance when compared with the pure Ag2MoO4 (59.6%) and CaWO4 (14.3%) under visible light. The scavenging test revealed that the key species responsible for the degradation of MB dye was hydroxide radical (•OH). The degradation of MB was well fitted to the pseudo-first-order kinetics with a high regression coefficient value (R2 > 0.95). The photostability and reusability of the nanohybrid was studied and the nanohybrid showed almost same degradation efficiency even at 6th cycle. The nanohybrid showed enhanced antimicrobial activity against Escherichia coli and Bacillus subtilis. Therefore, CaWO4/Ag2MoO4 nanohybrid photocatalyst can be used as an effective candidate for environmental remediation through photocatalysis and bactericidal applications.

The unreported Bi6Cr2O15-Co3O4 nano-photocatalyst was prepared via facile sono-chemical route for the fabrication of a binary heterojunction. HRTEM analysis represents the spherical and rod-like morphology of Bi6Cr2O15-Co3O4. UV–vis DRS showed bandgap shift from 1.95 eV (Bi6Cr2O15) and 2.67 eV (Co3O4) to 2.25 eV for Bi6Cr2O15-Co3O4 with visible-light sensitization. X-ray photoelectron spectroscopy (XPS) confirmed the chemical states (Co2p, Cr2p, Bi4f and O1s). The dye degradation efficiency of Bi6Cr2O15-Co3O4 was highly boosted up to 3.8–8.8 times and the kinetic rate constant was 0.0062 min−1 compared with pristine counter parts (Bi6Cr2O15 = 0.0016 min−1; Co3O4 = 0.0007 min−1). The remarkably enhanced photocatalytic activity was ascribed to its higher specific surface area (27.118 m2/g) and the existence of a synergic effect between pristine counter parts that resulted in suitable bandgap and reduced recombination of e-/h+ pairs. The Bi2CrO6-Co3O4 showed only negligible reduction in degradation performance after six recycles showing its excellent stability and resistance to photo-corrosion. The ·OH and h+ were the key species involved in dye degradation. The Bi6Cr2O15-Co3O4 exhibited excellent antimicrobial activity against Escherichia coli and Bacillus subtilis. Therefore, Bi6Cr2O15 decorated Co3O4 nano-photocatalyst can be used as an effective candidate for environmental remediation through photocatalysis and for bactericidal applications.

Novel CoS/Ag2WO4 photocatalyst have been synthesized successfully by facile chemical precipitation method under normal pressure. The prepared nano photocatalysts were characterized with UV–vis DRS, TEM, XRD, PL, Raman spectroscopy, EDAX, N2 adsorption-desorption, XPS and FT-IR. The present work describes the enhanced photocatalytic and antimicrobial activity of CoS/Ag2WO4 nanocomposites (NCs). The K value for MB degradation was 0.089 min−1 by CoS/Ag2WO4 which was 8.9 and 3.1 times greater when compared with 0.01 min−1 by Ag2WO4 and 0.028 min−1 by CoS respectively. The broad-spectrum antibacterial property was exhibited by NCs against gram-ve (E. coli) and gram +ve (B. subtilis) bacteria. The NCs showed enhanced photostability and reusability even after six cycles. The scavenging test confirmed that hydroxyl radicals (OH•) were the major species involved in photocatalytic degradation process under visible light irradiation. The results of the present study can be applied in practical application in the area of photocatalysis and antimicrobial applications.

The biochar is a solid carbon-rich, porous material produced by the thermochemical conversion of a diverse range of biomass feedstocks under an inert atmosphere (i.e., in the absence of oxygen). We can produce the biochar at all likely scales, ranging from the industrial to the domestic level and even at individual farms, thus, the biochar industry is leading as a most appropriate at different socioeconomic settings. The possibility of sustainable biochar production practices and multi-functionality features make it a promising candidate to fulfill an increasing demand in the fields of soil amendment, agricultural sustainability, environmental protection, cutting-edge materials, and to achieve circular bioeconomy and mitigation of climate change. An available fraction of waste biomass (agroforestry waste, biomass crops, agricultural residues, mill residues, and animal manure, and many more) can be used efficiently in pyrolysis and converted into desired biochar materials, besides this alternative energy products, such as syngas, bio-oil, electricity generation, and process heat. This report emphasizes the fate of biomass composition, pyrolysis mechanisms, and applications of modern analytical and characterization techniques that are being adopted, applied, and standardized to improve understandings of molecular, structural, and surface properties characteristics of biochar. To achieve precisely designed biochar, there is a need to understand the latest advances in biochar materialization mechanisms and structure-application relationships to speed up their agronomic applications and to achieve a zero-waste dream. This report also summarizes a wide range of literature published on feedstocks, pyrolysis, and biochar and suggests several practical recommendations appropriate to implement and bring together specific details on the thermochemical conversion of biomass, desired biochar properties, organic and inorganic phases, and the significance to the agronomic applications.

Glucose encapsulated cadmium oxide nanoparticles (G-CdO NPs) were synthesized by a sol-gel method. An array of different physical methods was used to characterize G-CdO NPs, including ultra violet-visible spectroscopy (λMax - 275 nm), transmission electron microscopy (TEM; 17 ± 1 nm), and zeta potential (−8.24 ± 0.4 mV) analyses. The NPs were active against HeLa cells (IC50 - 31.58 μg/mL) and Saos-2 cells (IC50 - 12.51 μg/mL) by preventing glycation (early, 95%; late, 65%). G-CdO NPs were effective anti-glycating agents and were highly effective against advanced glycation end products in particular. Localization of G-CdO NPs in the mitochondria and nuclei of cells was confirmed by TEM. Reactive oxygen species generated in the treated cells (confirmed by 2′,7′-dichlorofluorescin diacetate based assay) caused disintegration of mitochondrial cristae, disruption of the membrane integrity, and condensation and degradation of the nuclei. The LD50 of G-CdO NPs on Swiss Albino mice was 1.432 mg/kg of body weight. The results indicate the potential therapeutic value of G-CdO NPs.