Base metals (Ni, Cu, Zn, Fe) oxide nanomaterials mediated photo/sono-catalytic removal of emerging pharmaceutical contaminants from wastewater

Photo/sono-catalytic techniques are being extensively considered for the degradation and removal of emerging contaminants (EC), including pharma-based organic pollutants. Transition metal-based nanomaterials have been studied as adsorbent/catalytic material in photo/sono-catalytic techniques for complete elimination/degradation/mineralization of pharmaceutical-based EC from wastewater streams. Various structural properties with dimensionalities of earth-abundant base metals (Ni, Fe, Cu, and Zn) oxides and their doped hybrid/composites, have been recently studied for removal/degradation/mineralization of EC from solution on the laboratory scale and industrial effluent of pharma-sectors. The oxides of earth-abundant base metals nanomaterials have been summarised and discussed in this review along with the general mechanism of degradation/elimination with acceptable results related to wastewater stream detoxification and recyclability of catalytic material during degradation/removal of EC. The surface properties like transfer of electrons and holes, surface area, surface modification and doping with reusability value of these materials are primacy factors for their applicability in the degradation/removal of organic pollutants from wastewater and substantial treatment. This study would be helpful for their use and development of cutting-edge materials for waste/surface water treatment on a large scale in a sustainable and cost-effective manner.