Molecular precursor-mediated facile synthesis of photo-responsive stibnite SbS nanorods and tetrahedrite CuSbS nanocrystals.

Stibnite SbS and tetrahedrite CuSbS nanostructures being economical, environmentally benign and having a high absorption coefficient are highly promising materials for energy conversion applications. However, producing these materials especially tetrahedrite in the phase pure form is a challenging task. In this report we present a structurally characterized single source molecular precursor [Sb(4,6-MepymS)] for the facile synthesis of binary SbS as well as ternary CuSbS in oleylamine (OAm) at a relatively lower temperature. The as-prepared SbS and CuSbS nanostructures were thoroughly checked for their phase purity, elemental composition and morphology by powder X-ray diffraction (pXRD), electron dispersive spectroscopy (EDS) and electron microscopy techniques. pXRD and EDS studies confirm the formation of phase pure, crystalline orthorhombic SbS and cubic CuSbS. The SEM, TEM and HRTEM images depict the formation of well-defined nanorods and nearly spherical nanocrystals for SbS and CuSbS, respectively. The SbS nanorods and CuSbS nanocrystals exhibit an optical bandgap of ∼1.88 and 2.07 eV, respectively, which are slightly blue-shifted relative to their bulk bandgap, indicating the quantum confinement effect. Finally, efficient photoresponsivity and good photo-stability were achieved in the as-prepared SbS and CuSbS nanostructure-based prototype photo-electrochemical cell, which make them promising candidates for alternative low-cost photon absorber materials.