The field of thermoelectric materials has a long history spanning decades. After initial development phase, only incremental improvements were made to energy conversion materials in terms of their efficiency. Recently however, the integration of nanotechnology to thermoelectric materials has lead to a surge in research because of the development of new nano-based techniques for improving thermoelectric efficiency. The field is now advancing rapidly and there is a marked shift from bulkscale non-sustainable materials towards sustainable bottom-up produced nanoparticle materials. Herein, we present a summary of some of the key findings in the field that have led to our own studies and development from tellurium containing nanoparticles to sustainable sulfide nanomaterials. A summary of research advancements along with the challenges associated with the developing nanoparticle based thermoelectric technology will be discussed for nanoparticle systems including the classic tellurides as well as new sustainable materials such as copper sulfide and copper iron sulfide.