Transition metal ions as a tool for controlling the photocatalytic activity of MWCNT-TiO2 nanocomposites

• Published in: Journal of alloys and compounds 2022-11, Vol.921, p.166095, Article 166095
• Main Authors: Toloman, Dana, Stefan, Maria, Pana, Ovidiu, Rostas, Arpad Mihai, Silipas, Teofil Danut, Pogacean, Florina, Pruneanu, Stela, Leostean, Cristian, Barbu-Tudoran, Lucian, Popa, Adriana
• Format: Article
• Language: English
• Subjects: Anatase; Aqueous solutions; Catalytic activity; Copper; Diffraction patterns; Electrochemical analysis; EPR; Manganese; MWCNT-TiO2 composites; Nanocomposites; Nanoparticles; Optical properties; Oxygen vacancies; Photocatalysis; Rutile; Titanium dioxide; Transition metal ions; Transition metals; Ultraviolet radiation; Valence; X ray photoelectron spectroscopy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.166095

MWCNT decorated with undoped and Cu or Mn-doped TiO2 nanoparticles were synthesized successfully. PXRD patterns show the diffraction plans specific to MWCNT, anatase, and rutile phases of TiO2. The ratio between anatase and rutile phases differs from sample to sample. Through EPR spectroscopy, the defect and the valence states of the dopant ions in the TiO2 lattice were shown and correlated with XPS results. The morphology of the samples was analyzed by SEM and TEM. The photocatalytic activity of the samples was evaluated against RhB aqueous solution under UV irradiation. The sample containing Cu2+ ions has the best photocatalytic performance. The photocatalytic mechanism was explained based on the correlation of structural characteristics, optical properties, ROS species generation, and scavenger experiments. The electrochemical performance of the SPE electrode modified with MWNCT-TiO2:Cu towards RhB detection was tested, and the obtained sensitivity is higher than that corresponding to bare SPE. [Display omitted] •MWCNT decorated with undoped and Cu or Mn doped TiO2 were synthesized.•The doping influence the stabilization of a certain polymorphic phase of TiO2.•EPR evidenced the defect and valence states of dopant ions from TiO2 lattice.•All samples show photocatalytic activity Cu doping ensuring the best performances.•The Cu doped sample works as sensor material for electrochemical RhB detection.