Bi-efficacious incorporation of Indium in TiO2/PbS based nanocomposites for photocatalytic and solar paint applications

Quantum-dot (QD) sensitized TiO2 nanocomposites are currently emerging as efficient photovoltaic and photocatalytic materials and thus extensively investigated to obtain superior light harvesting. TiO2 coupled with PbS QDs (TiO2/PbS) offers excellent absorbance of solar irradiation, ensuing significant electron-hole generation that can be utilized for carrying out photovoltaic activity in solar cells or dye degradation process. However, TiO2/PbS nanocomposite suffers from detrimental charge carrier recombination and photo-corrosion in an electrolyte/aqueous environment which lowers down its performance. In this study, we have revealed the bi-efficacious role of Indium (In) incorporation during the conventional synthesis (i.e. successive ionic layer adsorption and reaction; SILAR) of TiO2/PbS nanocomposite. Resultantly, the modified processes enabled us to achieve In-doped and In2S3 deposited PbS QDs, which respectively produced improved opto-electronic behavior and photostability of TiO2/PbS nanocomposites. On the one hand, In-incorporated TiO2/PbS NC exhibited 100% higher degradation of toxic Congo Red dye than reference TiO2/PbS, while it showed ∼3 mA/cm2 higher photocurrent density (Jsc) and around 1.49% power conversion efficiency (PCE) when utilized for the development of solar paint-based photoanode in QDs sensitized solar cell (QDSSC). Along with extensive material characterization of reference and In-incorporated TiO2/PbS NCs, electrochemical characterization was carried out to affirm the efficacy of modification of conventional SILAR process and resultant TiO2/PbS NCs.