A critical review of synthesis parameters affecting the properties of zinc oxide nanoparticle and its application in wastewater treatment

In this era, nanotechnology is gaining enormous popularity due to its ability to reduce metals, metalloids and metal oxides into their nanosize, which essentially alter their physical, chemical, and optical properties. Zinc oxide nanoparticle is one of the most important semiconductor metal oxides with diverse applications in the field of material science. However, several factors, such as pH of the reaction mixture, calcination temperature, reaction time, stirring speed, nature of capping agents, and concentration of metal precursors, greatly affect the properties of the zinc oxide nanoparticles and their applications. This review focuses on the influence of the synthesis parameters on the morphology, mineralogical phase, textural properties, microstructures, and size of the zinc oxide nanoparticles. In addition, the review also examined the application of zinc oxides as nanoadsorbent for the removal of heavy metals from wastewater.