Ag‐Induced Defect States in ZnO/GO Nanoworms for Efficient Solar‐Driven Removal of Ciprofloxacin and Organic Dyes

ABSTRACT

Ag‐induced defect states in ZnO/GO (AZGO) nanoworms were prepared by ultrasonication‐assisted hydrothermal method for enhanced solar‐driven degradation of antibiotic ciprofloxacin (CPF) and organic dyes, methylene blue (MB) and rhodamine B (RhB). Structural characterization revealed that controlled Ag incorporation promoted microstructural evolution by increasing the crystallite size (18 to 24 nm), reducing lattice strain (6.36×10 ⁻³ to 4.86×10 ⁻³ ), and narrowing the optical bandgap from 3.33 to 3.04 eV for Ag concentration of 3 at%. FESEM and TEM analyses confirmed the formation of nanoworm‐like structures, while ESR measurements demonstrated an increased density of oxygen‐vacancy‐related defect centers. These defect states, together with the conductive GO network, facilitated efficient charge transport and suppressed electron–hole recombination, further supported by reduced interfacial charge‐transfer resistance. The DFT calculation results revealed the defect‐induced modulation of the electronic structure of AZGO, including narrowed bandgap and enhanced charge delocalization, which were consistent with the experimental results. As a result, the optimal AZGO (3 at%) nanoworms exhibited enhanced catalytic performance with 96%/97% of degradation of MB/RhB within 60/90 min of illumination, and 98% mineralization of CPF within 180 min. The generation of various intermediates was confirmed by HPLC‐MS analysis, while the key reactive oxygen species were identified by scavenging experiments.