Aminocaproic acid mixed methanolic lead–thiourea complex precursor and its thermal decomposition to star-shaped lead sulfide crystals

In this work, we present for the first time a simple synthetic route to fabricate a controlled lead sulfide (PbS) structure using amino acid mixed precursor. High yield star-shaped PbS crystals were developed by solvothermal synthesis technique using an environment friendly aminocaproic acid (ACA) mixed methanolic Pb–TU complex precursor at 170 °C for 20 h. The mechanism leading to these star-shaped PbS crystals was discussed. The as-synthesized PbS crystals were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR). The obtained results show that the synthesized star-shaped PbS crystals were exempt of impurities and were crystalline with cubic phase. Finally, the FTIR study indicates that molecules were bounded on the surface of PbS crystal via nitrogen lone pair of the amino head groups.

► A new aminocaproic acid mixed methanolic Pb-TU complex precursor was prepared.
► Star-shaped PbS crystals produced by precursor solvothermal decomposition.
► A possible mechanism for the formation of the star-shaped PbS crystals.