HO 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 HO 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 (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 HO mediation, resulting in a significant reduction of bond-breaking energy barriers. As a result, the consumption rate of HO was reduced by two-thirds in the presence of ECs. In contrast, the removal of ECs was increased approximately 95-fold mediated by trace HO. It exhibits the highest catalytic performance with the lowest dosage of HO among numerous similarly reported systems. This discovery is significant for the development of water self-purification expansion technologies.