Fig. 4From: Renewable Lignosulfonate-Assisted Synthesis of Hierarchical Nanoflake-Array-Flower ZnO Nanomaterials in Mixed Solvents and Their Photocatalytic PerformanceImages of the hierarchical flower-like ZnO nanostructure: a high-magnification SEM, b high-magnification SEM with 500 nm, c TEM, and d HRTEMBack to article page