Interfacial Ag-N Coordination-Induced C-N Bond Activation Enabling Sustainable Photocatalytic Glyphosate Degradation.

The interfacial coordination between transition metal active sites and nitrogen-containing pollutants represents a promising strategy to enable rapid and efficient photodegradation, holding profound implications for environmental remediation. Residual glyphosate (GP) herbicide in natural environments is typically degraded into a more toxic intermediate ((aminomethyl)phosphonic acid, AMPA) that hinders subsequent mineralization and phosphorus resource recovery. Herein, this study constructs an eco-friendly photocatalytic system using Ag cocatalyst-selectively modified BiVO4 (Ag/BiVO4) for sustainable GP degradation and mineralization. Photocatalytic results demonstrate that Ag/BiVO4 achieves almost 98.8% GP degradation efficiency within broad pH conditions, with a kinetic constant of 0.1087 min-1, 23.1-fold higher than that of pristine BiVO4 (0.0047 min-1). Notably, Ag/BiVO4 realizes high-efficiency mineralization by fully oxidizing the AMPA intermediate to PO43- (42.8 μmol L-1), whereas pure BiVO4 only accumulates the AMPA intermediate (8.95 μmol L-1) without PO43- generation. Furthermore, photodegradation assays of diverse pollutants confirm that Ag/BiVO4 preferentially degrades N-containing pollutants, implying specific interfacial interactions between Ag active sites and N-containing compounds. In situ ATR-FTIR, XPS, and electrochemical characterizations verify that interfacially formed Ag-N coordination between the Ag cocatalyst and GP or AMPA can accelerate photocarrier transfer and promote C-N bond activation, thereby enhancing GP photodegradation efficiency. Radical capture experiments and EPR spectroscopy further reveal that O2 activation into •O2- and hole species dominate the eco-friendly degradation of GP and AMPA. This work offers valuable insights into the metal-N coordination-mediated photocatalytic organic pollutant degradation for sustainable wastewater remediation and resource recovery.