H₂O₂ Triggering Electron-Directed Transfer of Emerging Contaminants over Asymmetric Nano Zinc Oxide Surfaces for Water Self-Purification Expansion

Slow mass transfer processes between inert emerging contaminants (ECs) and dissolved oxygen (DO) limit natural water self-purification; thus, excessive energy consumption is necessary to achieve ECs removal, which has become a longstanding global challenge. Here, we propose an innovative water self-purification expansion strategy by constructing asymmetric surfaces that could modulate trace H₂O₂ as trigger rather than oxidant to bridge a channel between inert ECs and natural dissolved oxygen, achieved through a dual-reaction-center (DRC) catalyst consisting of Cu/Co lattice-substituted ZnO nanorods <i>in situ</i> (CCZO-NRs). During water purification, the bond lengths of emerging contaminants (ECs) adsorbed on the asymmetric surface were stretched, and this stretching was further enhanced by H₂O₂ mediation, resulting in a significant reduction of bond-breaking energy barriers. As a result, the consumption rate of H₂O₂ was reduced by two-thirds in the presence of ECs. In contrast, the removal of ECs was increased approximately 95-fold mediated by trace H₂O₂. It exhibits the highest catalytic performance with the lowest dosage of H₂O₂ among numerous similarly reported systems. This discovery is significant for the development of water self-purification expansion technologies.