"Enhancing Wastewater Treatment: DFT and experimental insights into ZnO-implanted TiO2 Z-Scheme Photocatalyst mediated via Smilax aspera"

This comprehensive study aimed to optimize the performance of photogenerated carriers in catalytic and optoelectronic systems by effectively separating electron-hole pairs. Green-synthesized TiO₂ nanoparticles (average size ∼21 nm) and zinc acetate (99.5% purity), augmented with eco-friendly integration of the plant Smilax aspera, resulted in a tailored hollow direct Z-scheme photocatalyst, ZnO-TiO₂, with adjustable ZnO loading ranging from 0.5 wt% to 5 wt%. Characterization techniques such as X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Ultraviolet-Visible Spectroscopy, Transmission Electron Microscopy, Thermogravimetric Analysis and Energy-Dispersive X-ray Spectroscopy provided detailed insights into the atomic and electronic properties of the material. The analysis revealed the coexistence of anatase TiO₂ and wurtzite ZnO phases, each exhibiting distinct electronic band structures within the composite. Density functional theory calculated band gap values of 2.02 eV for TiO₂ and 2.89 eV for ZnO-TiO₂ corroborated the experimental results, offering a deeper understanding of electronic transitions within the heterojunction. The ZnO-TiO₂ composite showed significant photocatalytic efficacy in degrading Methylene Blue (98% in 15 min) and Rose Bengal (79.69% in 40 min) under UV light. It also exhibited antifungal potential against Aspergillus niger and Candida albicans, with inhibition zones of 28.0±0.12 mm and 30.23±0.68 mm, respectively. This research provides valuable insights into the eco-friendly, multifunctional applications of the ZnO-TiO₂ Z-scheme photocatalyst. This research thus provides valuable insights into the multifaceted applications of this synergistic, eco-friendly heterojunction photocatalyst in environmental remediation and its role as an effective antifungal agent.