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 H 2 O 2 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 H 2 O 2 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 dual-functional photocatalytic systems in environmental remediation.