After synthesis, the morphology as prepared BNNS-Arg and bulk hBN were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and highresolution transmission electron microscopy (HRTEM). Under SEM (Figure and), BNNS-Arg showed reduced size (~0.1 μm) and thickness (~1 nm) compared to bulk hBN (size: ~1.5 μm; thickness: ~60 nm). As shown in Figure and 1F, the TEM images presented that after arginine facilitated exfoliation and function, BNNS-Arg exhibited 2D structure as well as fewer layers compared to bulk hBN. The thinner structure of BNNS-Arg was further confirmed by HRTEM results (Figure and). The contrast of bulk hBN to the background was higher than BNNS-Arg, which showed the thicker nature of bulk hBN. These results demonstrated the effective BNNS exfoliation. After laccase immobilization, formed BNNS-Arg@Lac still presented the same morphology as BNNS-Arg, which confirmed the nanosheet structure of our catalysts. Moreover, element mapping has been conducted to verify the successful linkage between laccase and BNNS-Arg, for BNNS-Arg only B, N, C, and O were observed on the surface (Figure ). However, in addition to these elements, laccase-exclusive elements: Cu and S were also observed on BNNS-Arg@Lac, which demonstrated laccase has been loaded on the BNNS-Arg surface (Figure ).