Synergistic effect of PbS nanoparticle deposition on TiO2 nanotubes for efficient indoor air remediation

Abstract

This study investigated the photocatalytic performance of PbS-NPs/NTs-TiO₂ photocatalysts for the degradation of Butane-2, 3-Dione (BUT). The impact of decorating dioxide nanotubes (TiO₂-NTs) with lead sulfide nanoparticles (PbS-NPs) on the degradation of volatile organic compounds (VOCs) was the focus of the investigation. The titanium dioxide nanotubes (TiO₂-NTs) were synthesized by electrochemical anodization of a titanium-based substrate. At the same time, lead sulfide nanoparticles (PbS-NPs) were deposited using the pulsed laser deposition (PLD) technique. The mean diameter of PbS-NPs increased from approximately 10 nm to 20 nm as we modified the laser ablation pulse number (N_LP) from 500 to 10 000. The cubic crystalline phase of PbS nanoparticles was revealed by X-ray diffraction analysis. An increase in the number of laser ablation pulses led to PbS-NPs aggregation, as indicated by observations in scanning electron microscopy (SEM). The PbS surface exhibited a compact and uniform morphology with strong adherence to the substrate, as demonstrated by Atomic Force Microscopy (AFM) analysis. The roughness (R_ms) transitioned from 52 nm for pure TiO₂-NTs to 111 nm for N_LP = 5000, decreasing to 22 nm for N_LP = 10 000. Photoluminescence (PL) spectra showed that lower PL intensity was exhibited by PbS-NPs/TiO₂-NTAs compared to pure NTs, with the lowest PL intensity observed for N_LP = 5000. Absorbance spectra of TiO₂-NTAs adhered to quartz substrates revealed a calculated band gap of 3.1 eV for TiO₂. The nanocomposite demonstrated high photocatalytic performance in BUT removal when the PbS nanoparticles were deposited at an optimal laser pulse count of N_LP = 5000. Results indicated that superior BUT adsorption and degradation capabilities were possessed by the PbS-NPs-modified TiO₂-NTs when compared to pure TiO₂-NTs. Notably, the highest photocatalytic activity with an efficiency exceeding 75% was exhibited by PbS-NPs/TiO₂-NTs-5000.