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Boosted H 2 O 2 utilization and selective hydroxyl radical generation for water decontamination: Synergistic roles of dual active sites in H 2 O 2 activation.

Can FengHeng ZhangJianhua GuoSi-Ying YuMengfan LuoJing ZhangYi RenYang LiuPeng ZhouChuan-Shu HeZhaokun XiongYue YuanYan WuBo Lai
Published in: Water research (2024)
H 2 O 2 as a green oxidant plays a crucial role in numerous green chemical reactions. However, how to improve its activation and utilization efficiency as well as regulate the distribution of ROS remains a pressing challenge. In this work, a sulfur quantum dots (SQDs) modified zero-valent iron (SQDs@ZVI) was delicately designed and prepared, whose iron sites can coordinate with strongly electronegative sulfur atoms to construct highly reactive Fe-S dual active sites, for high-efficient selective H 2 O 2 activation and utilization with potent • OH production. Experimental tests, in situ FTIR/Raman spectra and theoretical calculations demonstrated that SQDs modulates the local coordination structure and electronic density of iron centers, thus effectively enhancing its Fenton reactivity and promoting the rate-limiting H 2 O 2 adsorption and subsequent barrierless dissociation of peroxyl bonds into • OH via the formation of bridged S-O-O-Fe complexes. Consequently, substantial generated surface-bound • OH induced by the highly reactive Fe-S dual sites enabled excellent degradation of miscellaneous organic pollutants over a broad pH range (3.0-9.0). The developed device-scale Fenton filter realized durable performance (up to 200 h), verifying the vast potential of SQDs@ZVI with diatomic sites for practical application. This work presents a promising strategy to construct metal-nonmetal diatomic active sites toward boosting selective activation and effective utilization of H 2 O 2 , which may inspire the design of efficient heterogeneous Fenton reaction for water decontamination.
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