Figure 2. ( a ) XRD pattern of BiNSs and N ‐ BiNSs. Characterization of N ‐ BiNSs: ( b ) SEM image, ( c ) Figure 2. ( a ) XRD pattern of BiNSs and N-BiNSs. Characterization of N-BiNSs: ( b ) SEM image, Figure 2. ( a ) XRD pattern of BiNSs and N ‐ BiNSs. Characterization of N ‐ BiNSs: ( b ) SEM image, ( c ) TEM image, ( d ) HR ‐ TEM image, ( e ) HAADF ‐ STEM and ( f – h ) EDS mapping (green and red TEM image, ( d ) HR ‐ TEM image, ( e ) HAADF ‐ STEM and ( f – h ) EDS mapping (green and red ( c ) TEM image, ( d ) HR-TEM image, ( e ) HAADF-STEM and ( f – h ) EDS mapping (green and red represent N, Bi element, respectively). represent N, Bi element, respectively). represent N, Bi element,