Three-dimensional (3D) objects with a periodic structure composed of particles differing in composition and/or morphology have attracted a lot of attention due to their high potential for achieving new sets of properties nonexistent in single-phase materials and materials lacking a periodic structure. In this work, we have demonstrated a possibility of synthesizing a periodic heterostructure consisting of layers of nanocrystalline β-bismuth oxide and layers of spherical particles of metallic bismuth in a single step by conducting partial reduction of [Bi6O5(OH)3](NO3)5·3H2O in benzyl alcohol. The synthesis method of micrometer-sized particles of nanocrystalline β-Bi2O3/spherical Bi with a 3D periodic structure is proposed in this work for the first time. The mechanisms governing the interface formation during the synthesis of the β-Bi2O3/spherical Bi alternating-layer structure are discussed. The structural evolution of [Bi6O5(OH)3](NO3)5·3H2O during its partial reduction in benzyl alcohol shows an example of the strong interrelation between the phase composition, morphology and architecture of the reaction products derived from a single-phase precursor. The proposed synthesis method of the β-Bi2O3/spherical Bi alternating-layer 3D materials is easily scalable, shows good reproducibility and is based on simple experimental procedures.