Innovative eco-friendly materials for environmental remediation: when photocatalysis meets sustainability

Efforts to optimize pollution control technologies have been recently intensified to minimize harmful emissions in water and air, aligning with stringent legislative requirements [1]. Heterogeneous photocatalysis has emerged as a sustainable approach to mitigate toxic pollutants in the environment. However, its effectiveness is limited, and its enhancement remains a challenge [2]. The use of nano-sized materials, although common, raises concerns about nanotoxicity. The ideal photocatalyst should possess activity, selectivity, stability, non-toxicity, cheapness, and easy handling. Achieving all these requirements is a difficult task. In our recent work, we have focused on developing advanced TiO2-free materials for water and air remediation. Firstly, we have studied catalysts immobilized on eco-friendly supports able to eliminate organic pollutants from aqueous solutions. The economic advantage is the easy material recovery, and the utilization of floating supports enhances photocatalytic performances due to the large, exposed surface area and efficient aeration [3]. Secondly, we have studied silver-modified strontium titanates for degrading nitrogen oxides. Here, our challenge is to develop efficient materials stable at high temperatures [4] and active in the visible light region, harvesting sunlight or LED lighting in the interior. We have performed characterizations on morphology, structure, and metal speciation at the photocatalyst surface, elucidating potential and limitations of each material in the respective applications and providing critical insights into photocatalytic performances. [1] Guerra, F.D. et al., Molecules 2018, 23(7), 1760; [2] Djellabi, R. et al., Chem. Eng. 2021, 1:100696; [3] Galloni, M.G. et al., Catalysts 2022, 12(8), 923; [4] Djellabi, R. et al., Haz. Mat. 2022, 421, 126792.