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 PO₄^3- (42.8 μmol L^-1), whereas pure BiVO₄ only accumulates the AMPA intermediate (8.95 μmol L^-1) without PO₄^3- 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.