Effect of acidic and basic leachants on the synthesis of ZnO nanoparticles from Egyptian zinc ore, their optical/surface characteristics and photocatalytic performance

It is of pivotal significance to optimize the parameters affecting the extraction of metals from natural ores to convert them to value-added products. Owing to their semiconducting nature, most metal oxides, including ZnO, have various electronic, optical, and photocatalytic applications. Hence, we are investigating the leaching of Zn from Smithsonite (an Egyptian ore) using acidic/basic leaching agents (leachants). The leached salts were employed in a co-precipitation method followed by calcination to obtain crystalline ZnO nanoparticles. Both photocatalytic performance of the ZnO nanoparticles obtained from acid leaching and basic leaching were investigated toward the photodegradation of Rhodamine B dye. The ZnO(A) prepared using the acid leaching route has achieved about 5.6-fold enhancement in the dye photodegradation% and 5.3-fold enhancement in the observed rate constant compared to ZnO(B) prepared from basic leaching. Finally, the superior photocatalytic activity of the ZnO(A) is attributed to the smaller particle size, larger surface area, and existence of some defects that enhanced the photocatalytic performance.