Photodegradation of tetracycline and coupling photocatalytic H2O2 production driven by concave resins with different concavities under visible light irradiation

Background: The widespread presence of antibiotics in aquatic environments poses severe ecological risks due to inadequate removal in conventional wastewater treatment. This study investigates morphology-controlled concave polymer nanospheres for simultaneous tetracycline (TC) degradation and photocatalytic H2O2 production. Methods: Synthesis of aminophenol-formaldehyde resins (APF) using 3-aminophenol (3-AP), ammonia water, and formaldehyde. Through precise acetone-mediated etching, three concave resin catalysts with distinct concavities (70-78 nm) and wall thicknesses (47-54 nm) were synthesized. Significant findings: Systematic characterization revealed that increased wall thickness enhanced visible-light absorption (up to 700 nm), while higher concavity improved light reflection efficiency. The catalyst synthesized with 38 mL acetone demonstrated optimal H2O2 yield (168.5 mg g-1), whereas the maximum TC degradation efficiency (106.57 % at 180 min) was achieved using the 32 mL acetone-etched catalyst with the deepest concavity. Mechanistic studies identified synergistic effects between light scattering geometry and charge carrier dynamics, where concave structures facilitated multi-directional photon utilization while thickened walls suppressed electron-hole recombination. This work provides new insights into morphology engineering for dualfunctional photocatalytic systems in environmental remediation.