Atomically dispersed Ru-O3 anchored on the Ti3C2Tx surface with multiple reaction sites for the selective generation of single oxygen via peroxymonosulfate activation

Singlet oxygen ( 1 O 2 ) is an electrophilic oxidant capable of selectively eliminating contaminants in complex wastewater, which is highly expected in environmental remediation. However, due to the limitations in synthesizing catalysts with well-defined adsorption and active sites, the efficient and selective generation of 1 O 2 remains challenging. Herein, isolated Ru-O 3 moiety decorated two-dimensional Ti 3 C 2 T x catalysts (Ru-SA/Ti 3 C 2 T x ) were prepared to regulate 1 O 2 generation via peroxymonosulfate (PMS) activation. The constructed catalysts with asymmetric dual-metal structures (Ti-O-Ru) exhibited surprising mass activity of 1.4 × 10 4 min −1 ·mol −1 with a high 1 O 2 generation selectivity of 98.3 %. Mechanism inquiry indicated that the enhanced adsorption and electron transfer between PMS and Ru-SA/Ti 3 C 2 T x attributed to the synergistic effect of the strong adsorption at the Ru sites and the rapid electron transfer in the asymmetric Ti-O-Ru structures. Theoretical calculations demonstrated that Ru-O 3 moiety decreased the formation energy barrier of key intermediate *O, thus converting to a 1 O 2 -dominated oxidation path. Two possible degradation pathways of tetracycline hydrochloride (TCH) were proposed by gas chromatography-mass spectrometry (GC–MS), and the toxicities of intermediates were significantly decreased due to the strong electrophilic attack of 1 O 2 . This study deepened the understanding of the specific contribution of individual sites in multi-site synergistic, which furnished implications for the design and optimization of Fenton-like catalysts.