Hydrothermal synthesis of Mn2+ doped titanate nanotubes: Investigation of their structure and room temperature ferromagnetic behavior

Effects of the Incorporation of Distinct Cations in Titanate Nanotubes on the Catalytic Activity in NOx Conversion

“…Besides that, the silver incorporation to the NTs results in a solid with high crystallinity due to the organization of the monoclinic structure of the solid. Moreover, both inner and outer surfaces of NTs have negative charges, which allow the metals to be adsorbed on these surfaces [ 28 , 34 , 35 ].…”

“…Accordingly, NaNT has vibrational modes at around 158 (E1g), 195 (Eg), 276 (Ag), 445 (B1g), 656 (A1g), 696 (Ag) and 908 (Bg) cm −1 [ 25 ]. The weak bands at 156 and 192 cm −1 are attributed to the anatase-type structure of TiO 2 , whereas the modes at 276 and 656 cm −1 are due to the Na cation coordinated to the oxygen atom of the framework Ti–O vibration [ 25 , 35 ]. At 445 cm −1 , the Ti–O–Ti framework vibration is clearly visible [ 35 ].…”

The Use of Ultra-Small Fe3O4 Magnetic Nanoparticles for Hydrothermal Synthesis of Fe3+-Doped Titanate Nanotubes

“…However, in this case, mT instead of the observed value of about 9 mT. Example of research with the use of EPR analysis of hydrothermally synthesized Mn 2+ -doped titanate nanotubes can be found in paper [ 42 ].…”

“…The magnetic properties of ion-doped titanate nanotubes strongly depend on the method of their preparation and the type of ions used. For example, Fe 3+ -doping method presented in [ 34 ] yields hysteresis loops suggesting both paramagnetic and ferromagnetic contributions, the Co-doped titanate nanotubes in [ 41 ] show room temperature ferromagnetism, Gd 3+ -doped titanate nanotubes in [ 43 ] show low-temperature paramagnetism, Mn 2+ -doped titanate nanotubes in [ 42 ] show room temperature ferromagnetism.…”

“…The methods of doping titanate nanotubes with ions depend on the specific application. The examples of ions that are often used are Fe 3+ [ 34 , 35 , 36 , 37 , 38 ], Co 2+ [ 39 , 40 , 41 ], Ni 2+ [ 39 ], Mn 2+ [ 42 ], Gd 3+ [ 43 ], Yb 3+ [ 44 ], Nd 3+ [ 44 ], Au 3+ [ 45 ], Pt 2+ [ 45 ]. They show how diverse the methods of doping TiO 2 nanotubes are.…”