Tactical modification of pseudo-SILAR process for enhanced quantum-dot deposition on TiO2 and ZnO nanoparticles for solar energy applications

Pseudo successive ionic layer adsorption and reaction (p-SILAR) process is a unique route to develop quantum-dot (QD) sensitized nanocomposites (NCs) via QDs deposition on metal oxide nanoparticles (NPs). In this work, we have successfully increased the deposition of PbS and CdS QDs on TiO₂ as well as ZnO NPs using a simple wet chemical modification of p-SILAR. An optimal fluorination treatment of both NPs with 0.1 M aqueous solution of NH₄F was carried out under centrifugation. Consequent increase in deposition of PbS and CdS QDs was affirmed using scanning electron microscopy, EDX, UV–vis spectroscopy and XRD. Eventually, solar paint based photovoltaics and photocatalysis were carried out to show that modification of p-SILAR enabled TiO₂-PbS NC to exhibit 30% increase (from 6.5 mA/cm² to 8.5 mA/cm²) in the photocurrent density (J_SC) of solar cells and more than 11% increase (from 81% to 92%) in the degradation of congo red (CR) dye.