![]() ![]() 2 Among several semiconductors, TiO 2 has been proven to be one of the most widely used photocatalysts for decomposing organic compounds due to its strong redox ability, chemical and thermal stability and low cost. 1 Over the past years, various aspects of photocatalysis have been reviewed, and the importance of this technology for the remediation of air and water pollutants is well documented. Organic compounds such as chlorophenols, are used as pesticides, herbicides and disinfectants, and they are considered priority environmental pollutants. Water and air pollution are considered major environmental issues that should be urgently addressed. A healthy natural environment is vitally important for all ecosystems, and it is our responsibility to protect it. The natural environment is a priceless part of our heritage. Both methods, kinetics of degradation of 4-CP and TOC, provided similar results, revealing that the photocatalytic activity under UV light irradiation increased in the order 950C < 500 ☌ < 800 ☌ < 650 ☌ < TiO 2-P25. La 3+ could be regarded as a potential electronic promoter that can reduce the band gap of 2D TiO 2 nanosheets and can provide a signature of the electron transfer and carrier charge separation. The La 3+ cation, acting as a structural promoter, supported 2D TiO 2 growth with well controlled crystallite size, surface area and porosity. Upon annealing at 800 ☌, nanoscale lanthanum-enriched regions were generated due to the diffusive migration of La cations and phase transition from anatase to rutile. Material annealed at 650 ☌ exhibited the highest photocatalytic performance and achieved efficient TOC removal. Despite nearly identical tetragonal structures, replacement of Ti with La alters the photocatalytic activity through a reduction in band gap energies and an increase in charge carrier mobility. Rietveld refinement of the X-ray diffraction patterns confirmed the substitutional nature of the La cation that induced local structural variations and involved subtle ion displacement in the TiO 2 lattice due to the ionic size effect. Under annealing conditions, the freeze-cast precursor was transformed into an La-modified anatase with a well-defined 2D TiO 2 nanosheet morphology. Titanium dioxide modified with 3 wt% La was prepared via a green freeze-casting method, and its photocatalytic activity was tested in terms of its ability to degrade 4-chlorophenol (4-CP) and remove total organic carbon (TOC). Both methods, kinetics of degradation of 4-CP and TOC, provided similar results, revealing that the photocatalytic activity under UV light irradiation increased in the order 950C 2-P25. La3+ could be regarded as a potential electronic promoter that can reduce the band gap of 2D TiO2 nanosheets and can provide a signature of the electron transfer and carrier charge separation. The La3+ cation, acting as a structural promoter, supported 2D TiO2 growth with well controlled crystallite size, surface area and porosity. ![]() Rietveld refinement of the X-ray diffraction patterns confirmed the substitutional nature of the La cation that induced local structural variations and involved subtle ion displacement in the TiO2 lattice due to the ionic size effect. Under annealing conditions, the freeze-cast precursor was transformed into an La-modified anatase with a well-defined 2D TiO2 nanosheet morphology. ![]() ![]()
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