SYNTHESIS OF LEAD CHALCOGENIDES NANOCUBES AT ROOM TEMPERATURE BY SOLUTION CHEMICAL METHOD

Abstract

Energy crisis and thermal management related issues have been highlighted in the modern century due to escalating demands for energy consumption and global warming from fossil fuels. Sustainable and alternative energy sources are ever growing global concern. Thermoelectric (TE) materials have gained significant interest, due to effective solid‐state energy conversion from waste heat to useful electrical energy and vice versa. Clean, noise‐free, and environment‐friendly operation of TE devices has triggered great attention in viable technologies including automotive, military equipment, aerospace, and industries to scavenge waste heat into power. Till date conventional TE materials have shown limited energy conversion efficiency in the form of thermoelectric Figure of Merit (ZT). However, the concept of nanostructure and development of novel TE materials have opened excellent way to improve significant values of ZT. Nano‐engineered bulk TE materials allow effective phonon scattering at the high density of grain boundaries, which offer a way of lowering the thermal conductivity. Mass‐scale synthesis of TE nanomaterials is a challenge for the TE industry because of expensive fabrication processes involved. This study reports a bottom‐up chemical synthesis route performed at room temperature and can be utilized to produce highly pure, homogenous and highly crystalline TE lead chalcogenides nanoparticles of PbSe and PbTe. XRD patterns observed for synthesized powder confirm the pure phase of PbSe and PbTe. Cubic shape nanoparticles of PbSe and PbTe are synthesized successfully at room temperature as observed by scanning electron microscope images. The size of particles was calculated from high intense peak of XRD pattern using Debye Scherrer formula. Hence uniformly distributed regular cube particle of size 28.49 nm of PbSe and 30.975 nm for PbTe are observed.