H<sub>2</sub>O<sub>2</sub> Triggering Electron-Directed\nTransfer of Emerging Contaminants over Asymmetric Nano Zinc Oxide\nSurfaces for Water Self-Purification Expansion

Slow mass transfer processes between inert emerging contaminants\n(ECs) and dissolved oxygen (DO) limit natural water self-purification;\nthus, excessive energy consumption is necessary to achieve ECs removal,\nwhich has become a longstanding global challenge. Here, we propose\nan innovative water self-purification expansion strategy by constructing\nasymmetric surfaces that could modulate trace H<sub>2</sub>O<sub>2</sub> as trigger rather than oxidant to bridge a channel between inert\nECs and natural dissolved oxygen, achieved through a dual-reaction-center\n(DRC) catalyst consisting of Cu/Co lattice-substituted ZnO nanorods <i>in situ</i> (CCZO-NRs). During water purification, the bond\nlengths of emerging contaminants (ECs) adsorbed on the asymmetric\nsurface were stretched, and this stretching was further enhanced by\nH<sub>2</sub>O<sub>2</sub> mediation, resulting in a significant reduction\nof bond-breaking energy barriers. As a result, the consumption rate\nof H<sub>2</sub>O<sub>2</sub> was reduced by two-thirds in the presence\nof ECs. In contrast, the removal of ECs was increased approximately\n95-fold mediated by trace H<sub>2</sub>O<sub>2</sub>. It exhibits\nthe highest catalytic performance with the lowest dosage of H<sub>2</sub>O<sub>2</sub> among numerous similarly reported systems. This\ndiscovery is significant for the development of water self-purification\nexpansion technologies.