Molecular oxygen activation: Innovative techniques for environmental remediation

Molecular oxygen as a green, non-toxic, and inexpensive oxidant has displayed numerous advantages compared with other oxidants for more sustainable and environmentally benign pollutant degradation. Molecular oxygen activation stands as a groundbreaking approach in advanced oxidation processes, offering efficient environmental remediation with minimal environmental impact with the production of high-oxidation reactive oxygen species (ROS). The adaptability and energy efficiency of molecular oxygen activation significantly contribute to the progression of sustainable water remediation technologies. This review meticulously explores the principles and mechanisms of molecular oxygen activation, shedding light on the diverse ROS production pathways. Subsequently, this review comprehensively details contemporary activation approaches, including photocatalytic activation, electrocatalytic activation, piezoelectric activation, and photothermal activation, explicating their distinct activation mechanisms. Additionally, it delves into the promising applications of molecular oxygen activation in the degradation of water pollutants, primary air pollutants, and volatile organic compounds, providing an in-depth analysis of the associated degradation pathways and mechanisms. Moreover, this review also addresses the imminent challenges and emerging opportunities in environmental remediation. It is envisioned that this comprehensive analysis will spur ongoing exploration and innovation in the use of molecular oxygen activation for environmental remediation and beyond.