Bismuth-based nanostructured materials have been attracted great interest in a wide range of applications. In the present work, 3D (BiO)2CO3 hierarchical microspheres self-assembled by nanosheets were synthesized by a simple hydrothermal method. By using a facile anion-exchange strategy, (BiO)2CO3/amorphous Bi2S3 heterostructures were constructed through the controlled chemical reaction between (BiO)2CO3 microspheres and Na2S in an aqueous solution. The as-prepared samples were systematically characterized by XRD, SEM-EDX, TEM, FT-IR, XPS, UV-vis DRS and PL techniques. The heterostructured samples were applied for photocatalytic removal of ppb-level NO in air under visible light irradiation. The pure (BiO)2CO3 hierarchical microspheres exhibited decent visible light photocatalytic activity due to the surface reflecting and scattering effect. Amorphous Bi2S3 showed no photocatalytic activity due to narrow band gap. By hybridization of (BiO)2CO3 microspheres with amorphous Bi2S3 on the surface, 3D hierarchical (BiO)2CO3/amorphous Bi2S3 heterostructures were constructed, which demonstrated increased solar light absorption and highly enhanced visible photocatalytic activity and stability. The enhanced performance can be directly ascribed to the increased visible light utilization, promoted charge separation arising from the well-matched band structure and accelerated reactants transfer resulting from special 3D hierarchical structure. The present work opens a new avenue for modification of wide-band gap semiconductor with amorphous components, which could reduce the further thermal treatment and production cost.