This comprehensive review examines the advancements in composite thermoelectric materials that integrate nanoparticles, focusing on methods to enhance thermoelectric properties and fabrication procedures. The study explores various approaches to improve power factor and lattice thermal conductivity, emphasizing the influence of secondary phases and structural alterations. It investigates the impact of synthesis methods on electrical characteristics, particularly novel techniques like electrodeposition onto carbon nanotubes. The review also compares organic and inorganic thermoelectric materials, highlighting the potential of inorganic materials in waste heat recovery and power production. The introduction provides an overview of thermoelectricity, including the Seebeck, Peltier, and Thomson effects, and discusses the figure-of-merit (ZT) as a key metric for material efficiency. The review highlights the role of inorganic materials in improving energy efficiency and environmental sustainability. The literature review covers studies on Cu2Se and MoS2-based thermoelectric materials, detailing their synthesis, characterization, and performance enhancements through doping, nanostructuring, and other techniques. These advancements offer valuable insights for the development of more efficient and sustainable thermoelectric devices.This comprehensive review examines the advancements in composite thermoelectric materials that integrate nanoparticles, focusing on methods to enhance thermoelectric properties and fabrication procedures. The study explores various approaches to improve power factor and lattice thermal conductivity, emphasizing the influence of secondary phases and structural alterations. It investigates the impact of synthesis methods on electrical characteristics, particularly novel techniques like electrodeposition onto carbon nanotubes. The review also compares organic and inorganic thermoelectric materials, highlighting the potential of inorganic materials in waste heat recovery and power production. The introduction provides an overview of thermoelectricity, including the Seebeck, Peltier, and Thomson effects, and discusses the figure-of-merit (ZT) as a key metric for material efficiency. The review highlights the role of inorganic materials in improving energy efficiency and environmental sustainability. The literature review covers studies on Cu2Se and MoS2-based thermoelectric materials, detailing their synthesis, characterization, and performance enhancements through doping, nanostructuring, and other techniques. These advancements offer valuable insights for the development of more efficient and sustainable thermoelectric devices.