Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• characterized by various techniques such as TGA-DTA-DSC, UV–vis DRS, XRD, SEM, TEM, particle size analyzer (DLS) and the Brunauer–Emmett–Teller (BET) method. The band gap of the particles was calculated by using the Tauc plot. The photocatalytic activity of Ta2O5 nanoparticles was tested by the degradation of

• the organic dye rhodamine B. Keywords: bandgap; tantalum-oxo-ethoxide; Tauc plot; tantalum pentoxide (Ta2O5); Introduction Metal alkoxides, being excellent precursors in the sol–gel process for preparation of metal oxides have attained huge attention of researchers. Several attempts have been made

• material, E is the photon energy, Eg is the band gap energy and n is a constant of different values, 1/2, 3/2, 2 and 3, depending on the type of electronic transition, i.e., permitted/prohibited-direct or indirect transition. The band gap is calculated from a Tauc plot [27][28][29][30]. The band gap of the

Mesoporous cerium oxide nanospheres for the visible-light driven photocatalytic degradation of dyes

• Subas K. Muduli,
• Songling Wang,
• Shi Chen,
• Chin Fan Ng,
• Cheng Hon Alfred Huan,
• Tze Chien Sum and
• Han Sen Soo

Beilstein J. Nanotechnol. 2014, 5, 517–523, doi:10.3762/bjnano.5.60

• P25 TiO2 nanomaterials. The estimated band gap from the Tauc plot is approximately 2.7 eV (Figure 2b), which corresponds to an absorption edge in the blue region (460 nm). The reduced band gap compared to CeO2 can be attributed to the presence of oxygen vacancies, as previously reported [32]. The

• spectrum. (c) High-resolution XPS spectrum of mesoporous cerium oxide (black circles) with the overall fit (black) and the fits to Ce4+ (blue) and Ce3+ (red). (a) UV–vis diffuse reflectance spectra of cerium oxide nanospheres (black), 7 nm CeO2 (red) nanopowder, and P25 TiO2 (blue). (b) Tauc plot for