Modernized H2S-treatment of TiO2 nanoparticles: Improving quantum-dot deposition for enhanced photocatalytic performance

Abstract

One of the efficient strategies to enhance light harvesting capability of metal oxides nanoparticles (NPs) is to deposit low band gap metal sulfides on them via pseudo-successive ionic layer adsorption and reaction (p-SILAR). Resultant oxide-sulfide nanocomposites have a variety of applications, however there is still a need to increase the deposition of metal sulfide in the form of quantum-dots (QDs). In this work, we have successfully enhanced the deposition of QDs on TiO2 NPs using a modernized H2S-treatment strategy. A rotary reactor was employed for H2S-treatment of TiO2 NPs, ensuing higher deposition of PbS (in TiO2-PbS) and CdS (in TiO2-CdS) via p-SILAR. Resultantly, dye degradation of Rhodamine B increased from 63% to 75% and 72%-84%, respectively. X-ray photoelectron spectroscopy revealed the efficacy of modernized H2S-treatment while intensive electrochemical characterization affirmed reduction in charge carrier transfer resistances due to superior deposition of PbS and CdS QDs on TiO2 NPs.