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

## TL;DR

This study shows that adding lead sulfide nanoparticles to titanium dioxide nanotubes improves their ability to break down a harmful chemical in indoor air.

## Contribution

The novel contribution is demonstrating enhanced photocatalytic efficiency of PbS-decorated TiO2 nanotubes for VOC degradation.

## Key findings

- PbS-NPs/TiO2-NTs achieved over 75% efficiency in degrading Butane-2,3-Dione under optimal laser pulse conditions.
- Photocatalytic performance improved with PbS nanoparticle decoration, showing reduced photoluminescence and better adsorption.
- Surface roughness and nanoparticle size varied with laser pulse count, affecting photocatalytic activity.

## 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 (NLP) 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 (Rms) transitioned from 52 nm for pure TiO2-NTs to 111 nm for NLP = 5000, decreasing to 22 nm for NLP = 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 NLP = 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 NLP = 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.

This study investigated the photocatalytic performance of PbS-NPs/NTs-TiO2 photocatalysts for the degradation of Butane-2, 3-Dione (BUT).