Structural Mechanism of Copper Nanocrystals under Low Temperature and Partial Pressure: Insights from Powder X-ray Diffraction towards Malachite Green Dye Degradation

High crystalline symmetrical FCC copper nanoparticles (CuNPs) synthesized via a simple, unique chemical reduction pathway, with an induced 0.05 MPa partial pressure to establish a performance-structure-activity relation, is the prime goal of this study. The analysis provides comprehensive insights into the material characteristics through the powder X-ray diffraction (PXRD) and UV-visible techniques, significantly reducing multiple experimental trials and cutting costs. Those techniques explored the correlation between crystallographic parameters, including crystallite size 66.45 nm, micro-strain 1.90 × 10 -4 Nm -2 , lattice parameters a=b=c= 3.6176 Å, and unit cell volume 0.047343 Å 3 . The predominant dislocation density 3.03 × 10 -4 nm -2 , crystallinity index 1.45, specific surface area 11.67 m 2 /g, crystallinity percentage, and atomic packing factor (APF) 74.05 % were also explored. The UV-Visible absorbance analysis revealed a blue shift at 530.0 nm, indicating the nano-sized nature of the CuNPs, with a high optical band gap of 3.33 eV. The crystallographic findings confirmed the successful synthesis of highly crystalline FCC CuNPs, achieving a notable crystallinity of 58.30 % with a centrosymmetric orientation. The CuNPs catalyst demonstrated 87.21 % degradation efficiency against the malachite green dye, following first-order kinetics under sunlight irradiation. This highlights its potential for application in wastewater treatment system design. • 99.0 % crystalline copper phase and crystallinity 58.30 %. • FCC structure with lattice parameters a=b=c= 3.6176 Å and α=β=γ= 90.0°. • Pronounced diffraction occurred at 2θ= 43.310° with a dominating (111) plane. • Measured lattice strain 0.067 %, lattice volume 47.343 Å 3 and APF 74.05 %. • Crystallite size 66.45 nm, surface area 11.67 m 2 /g and preference growth 0.133. • Achieved 87.21% degradation following first-order kinetics for MG dye.