Structural, Optical, Photocatalytic and Electrochemical Studies of PbS Nanoparticles

Oleic acid (OA) and octadecylamine (ODA) capped lead sulphide (PbS) nanoparticles were prepared at 150, 190 and 230 degrees C. X-ray diffraction patterns indicates that the synthesized PbS nanoparticles were in the rock cubic salt crystalline phase. The particle sizes of the as-prepared PbS nanoparticles are in the range 2.91-10.05 nm for OA-Pb S(150), 24.92-39.98 nm for ODA-Pb S(150), 9.26 - 29.08 nm for OA-PbS(190), 34.54 - 48.04 nm for ODA-PbS(190), 17.96-88.07 nm for OA-PbS(230) and 53.60 - 94.42 nm for ODA-PbS(230). SEM images revealed flaky and agglomerated spherical like morphology for the nanoparticles. The energy bandgap of the PbS nanoparticles are in the range 4.14 - 4.25 eV, OA-PbS(230) have the lowest bandgap of 4.14 eV while ODA-PbS(150) have the highest bandgap of 4.25 eV. The PbS nanoparticles were used as photocatalyst for the degradation of Rhodamine B and OA-PbS(150) showed efficiency of 44.11% after 360 mins. Cyclic voltammetry of the PbS nanoparticles showed a reversible redox reaction and linear Randles-Sevcik plots indicates electron transfer process is diffusion controlled.