Effect of synthesis routes on the microstructural properties of nano zero-valent metals of Fe and Cu synthesized from the industrial copper solvent extraction process

Abstract

Nano zero-valent iron (NZVI) and nano zero-valent copper (NZVC) synthesizing from the present industrial solution could be attractive due to some advantages such as preparing advanced materials through cost-effective methods and solving their disposal problems. Moreover, the present microstructural investigation probed the influence of synthesis routes used on NZVI and NZVC properties. Accordingly, the microstructural properties of nano zero-valent metals (NZVMs) synthesized through the green and chemical methods were calculated by the Rietveld method. The obtained results verified that NZVI was synthesized with titrating NaBH4 and green tea extract by chemical and green techniques from the industrial raffinate solution. NZVC was prepared from the industrial Cu-enriched solution through green and chemical techniques by titrating ascorbic acid and NaBH4, respectively. XRD and Energy Dispersive Spectroscopy (EDS) proved that NZVMs were synthesized and fairly oxidized. Microstructural studies also revealed that the amorphization degree was increased from 62.2% and 2.7% in the green NZVI and NZVC to 89.8% and 86.81% in chemically synthesized NZVI and NZVC, respectively. Considering green NZVMs, the crystallite size and unit cell were reduced in chemically synthesized NZVMs. Also, the microstrain changed from 2.79E-4% and 3.2E-3% in the green NZVI and NZVC to 2.4E-2% and 6.2E-4% in chemically synthesized NZVI and NZVC, respectively. The findings of this study indicated that the chemically synthesized NZVMs had smaller particles, crystallite size, unit cells and a higher amorphization degree, in favor of reactivity promotion and oxidation progress.