Nanoparticles can enhance growth and yield of different plants due to their favorable physicochemical properties. This study investigated the effect of copper oxide (CuO) nanoparticles on biochemical and growth parameters of maize seedling. CuO nanoparticles were synthesized by co-precipitation method and characterized for their chemical composition, structure, surface morphology and size distribution. The size distribution was found in the range of 11–28 nm. The majority nanoparticles exhibited sizes between 20 and 26 nm. The effect of these nanoparticles on catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), sugar level, protein, and chlorophyll content of maize plants was investigated during early growth stages. A randomized block design was used to quantify the effect of CuO concentration on maize seedling. It was revealed that CuO nanoparticles have a stimulating effect on the growth of plantlets. However, high CuO concentrations induced an inhibitory effect on plant growth parameters. CAT, SOD, and POD were more influenced by 550 ppm concentration whereas sugar level, protein and chlorophyll content were more affected by 800 ppm concentration. Outcomes of present study reveal that CuO-NPs have the potential to increase growth and yield of maize, but their effect is concentration dependent. Further research is required to explore the best effective concentration of CuO-NPs and mode of applications for yield maximization of maize.

1. 1.1. Water pollution and energy sustainability are critical global problems. More than two billion people still lack access to safe drinking water and industrial effluents continue to contaminat...

Understanding the atomic structure of a material provides the foundation for explaining its macroscopic behavior and predicting its properties. This chapter describes copper’s atomic structure as the basis for its individual characteristics that have made it essential throughout human history. Copper’s electronic configuration (3d¹⁰4s¹) is also explored, highlighting how its single valence electron in the 4 s orbital enables exceptional electron mobility within its face-centered cubic (FCC) crystal structure. The chapter describes copper’s metallic bonding, characterized by delocalized electrons forming a “sea” around positively charged ions, and demonstrates how this arrangement directly enables its outstanding electrical and thermal conductivity. Various structural defects, including vacancies, dislocations, and grain boundaries, are analyzed for their influence on mechanical properties, particularly copper’s remarkable ductility and malleability. Advanced computational models simulating electron movement and atomic interactions at different temperatures provide further insights into structure-property relationships. Through a comprehensive examination of these structural features, the chapter establishes clear connections between atomic-level phenomena and macroscopic properties, offering a theoretical framework essential for understanding copper’s technological applications and developing novel copper-based materials with improved performance characteristics.

The development of efficient and chemically stable photocatalysts with improved charge separation is critical for the remediation of dye-contaminated wastewater. In this study, graphene oxide–magnesium oxide (GO/MgO) nanocomposites with ultralow GO loadings (0–0.05 wt.%) were synthesized through a co-precipitation route and evaluated for ultraviolet (UV)-driven methylene blue (MB) degradation. X-ray diffraction (XRD) results were consistent with the retention of the cubic MgO phase (JCPDS 45-0946) with crystallite refinement from 20.26 to 13.26 nm, while the slight peak-position variations were more consistent with interfacial strain than definitive lattice substitution. UV–visible diffuse reflectance spectra revealed a red shift and bandgap reduction from 5.11 to 4.71 eV. Fourier transform infrared (FTIR) and Raman spectra showed GO-related functional signatures and a decrease in the ID/IG ratio (0.886 → 0.830), suggesting strengthened interfacial interactions with increasing GO loading. The optimized 0.05 wt.% GO/MgO sample achieved 91.6% MB degradation within 180 min and exhibited a 5.24-fold enhancement in the apparent pseudo-first-order rate constant (k = 0.00290 min−1) relative to pristine MgO (0.01518 min−1). Photocatalytic efficiency was maximized at pH 7–9 with a catalyst dosage of 0.75 g L−1, and post-reaction XRD/FTIR analysis indicated good structural stability. The enhancement is attributed to crystallite refinement and GO–MgO interfacial charge-transfer pathways inferred from consistent structural/optical–kinetic correlations.