Self-sacrifice Te template synthesis of new phase PbmSb2nTem+3n nanorods via Pb2+/Sb3+ synergistic effect

Abstract

Nanocrystals have been attracted extra attention due to their unique characteristics, different from their bulk counterparts. Herein, we first synthesized the new stable phase of ternary Pb_mSb_2nTe_m+3n one-dimensional (1D) nanorods with a rough surface, using Te as sacrificial template. X-Ray diffraction techniques (XRD), field emission scanning electron microscopy (FE-SEM) and energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) analysis have been used to characterize and determine the structure and composition of the product. By carefully adjusting the experimental conditions, it was found that reaction factors including distinct solvent, the amount of alkali, reaction temperature, the ratio of reactants and growth time, play critical roles in the crystallization process of Pb_mSb_2nTe_m+3n nanorods. Thorough morphological characterization revealed that significant variation of the morphology of the products originated from varying the amount of Pb/Sb precursors injected. Reaction with excess Pb produces Pb_mSb_2nTe_m+3n nanocubes with size variations, whereas the initial morphology of the Te nanorod template with a rough surface was preserved in the presence of Sb. The Pb²⁺/Sb³⁺ synergistic effect was attributed to the difference of their reaction reactivity. A mechanistic model is proposed to account for these experimental findings. Furthermore, the optical band gaps (E_g) of Pb_mSb_2nTe_m+3n were investigated as well.