Synthesis and Characterization of Two‐Dimensional Porous ZnO and Their Adsorption Performance of Congo Red in Aqueous Solution

Abstract In this study, ultrathin two‐dimensional porous ZnO (2D porous ZnO) was successfully synthesized via a combined hydrothermal and ion exchange strategy. The structural evolution from Co(OH) 2 nanosheets to 2D porous ZnO was systematically characterized and validated through TEM, XRD, XPS, BET, and AFM. Results show that the unique 2D porous structure affords the material with a high specific surface area, excellent stability, and abundant adsorption sites. The as‐prepared 2D porous ZnO exhibited excellent adsorption performance for Congo Red (CR) dye, with a maximum adsorption capacity as high as 382 mg g −1 . This result was derived from a systematic evaluation of its adsorption behavior under various conditions, which also determined that the process followed the pseudo‐second‐order kinetic model and the Langmuir isotherm model. Overall, this 2D porous ZnO has superior adsorption capabilities for CR dye, demonstrating promise as an advanced adsorbent for organic dye removal. This work not only presents an efficient adsorbent for pollutant removal but also proposes a novel strategy for designing other functional 2D porous materials.