The upsurge of photocatalysts in antibiotic micropollutants treatment: Materials design, recovery, toxicity and bioanalysis

The excessive use of antimicrobial agents such as antibiotics and disinfectants for domestic purposes and industries polluted the water bodies severely in the recent past. Thus released antimicrobial agents negatively impact the environment and human health as it induce antimicrobial resistance (AMR) to microbes in the environment. Conventional biodegradation routes showed feasible antibiotics pollutants degradation. Nonetheless, they often demand a long time of operation (usually in days) and a major portion of the antimicrobial agents is left untreated unlike the complete oxidation with advanced oxidation processes. The residues of antibiotics left in the water bodies accelerate growth of microorganisms (bacterial, fungal, and viral) with AMR. In virtue of avoiding the catastrophe of widespread AMR, photocatalysis assisted antibiotic pollutant treatment is recently gaining a great popularity as an advanced oxidation process and has shown to be useful for the removal of antimicrobial compounds, mainly antibiotics. Recent review reports on photocatalytic antibiotic degradation focus on summarizing materials progress and antibiotics pollutants in chronological viewpoints. However, the relationship between photocatalytic materials and antibiotics oxidation reaction pathways and the toxicity of by-products are needed to be shown with better clarity to transfer the photocatalysis technique from lab to market in a safe way. This review critically analyzes the insights of energetic semiconductor structure lacking to achieve hydroxyl and superoxide radicals mediated antibiotics degradation, recommends new materials design (Z scheme) and standardization in the experimental designs, and also informs the influencing parameters on antibiotic degradation. It further assesses the possibility of recovering value-added chemicals from the photocatalytic treatment process and highlights the importance of environmental toxicity analysis. Overall, this review will be a resourceful guide for interdisciplinary researchers working on advanced photocatalysis and pharmaceutical pollutant treatment for achieving a sustainable ecology and initiating a circular economy in chemical industries.