Lead sulfide ( PbS ) nanocrystals anchored on nitrogen-doped multiwalled carbon nanotubes ( CNx ) have been synthesized employing an environmentally friendly and inexpensive wet chemistry process. CNx∕PbS composites have been examined by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Theorical ab initio calculations have been developed to determine the samples structural, morphological and optical properties to explain the experimental evidences. The PbS nanoparticles exhibit of 4 nm to 27 nm particle size with a face-centered cubic crystal structure and are homogeneously distributed along the carbon nanotubes. The nitrogen-doped CNTs acts as binding sites for the PbS clusters as ab initio theoretical study suggests.

    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Material synthesis
        2.2 Computational details
    3 Experimental and theoretical results
        3.1 Experimental description of the  composite
        3.2 Theoretical description of the  composite
    4 Conclusions
    Acknowledgements 
    References

• B. Rebollo‑Plata(Tecnológico Nacional de México-Instituto Tecnológico Superior de Irapuato)
• M. P. Sampedro(Facultad de Ingeniería Química BUAP)
• M. G. Gómez‑Espinoza(Departamento de Ingeniería Agroindustrial, Universidad Politécnica de Pénjamo)
• M. Guzmán‑Altamirano(Tecnológico Nacional de México-Instituto Tecnológico Superior de Irapuato)
• J. G. Cabal‑Velarde(Tecnológico Nacional de México-Instituto Tecnológico Superior de Irapuato)
• O. Portillo‑Moreno(Laboratorio de Materiales Sci., Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla)
• A. Lobo‑Guerrero(Área Académica de Ciencias de la Tierra y Materiales, Universidad Autónoma del Estado de Hidalgo,)
• M. López‑Fuentes(Complejo Regional Centro, BUAP)
• Raúl A. Morales‑Luckie(Centro Conjunto de Investigación en Química Sustentable)