Advances and prospects of coconut biomass derived CQDs in developing nanocatalysts for antibiotic removal from wastewater

Increased utilization of antibiotics has resulted in the growing presence of antibiotic residues in aquatic ecosystems. Therefore, removal of antibiotics from the contaminated wastewater is quite essential for making the aquatic ecosystem clean and sustainable. Recently, the implementation of nanocatalysts has been considered as one of the promising approaches to addressing the issue of wastewater treatment by removing antibiotic residues through photocatalytic degradation or adsorption techniques. In this context, carbon quantum dots (CQDs), because of their unprecedented catalytic properties, have been identified as a potential carbon-based nanomaterial. Furthermore, the preparation of CQDs can be performed by using waste biomass by employing them as a carbon source. Herein, as an abandoned bioresource, coconut biomass can be exploited to produce CQDs and their nanocomposites. Therefore, this review analyses the compositional structure and availability scope of coconut biomass along with exploring the development of CQDs via different methods and evaluating their physicochemical properties. Furthermore, the review shows that the biomass-derived CQD-based nano-photocatalysts and nano-absorbents show improved antibiotic removal efficiency by means of photocatalysis and adsorbing processes compared to their counterpart made from pure carbon. Therefore, the prospects of coconut biomass derived CQDs for their integration with nanomaterials for developing nano-photocatalysts and nano-adsorbents have been presented towards the removal of antibiotics. Furthermore, the possible mechanisms involving the antibiotic removal through nano-photocatalytic degradation and adsorption techniques have been discussed along with possible limitations and key challenges in this research area. This review may provide guidance for future research in solid waste management and wastewater treatment.