Nanostructured N doped TiO₂efficient stable catalyst for Kabachnik–Fields reaction under microwave irradiation

Abstract

Herein, we report nitrogen-doped TiO2 (N-TiO2) solid-acid nanocatalysts with heterogeneous structure employed for the solvent-free synthesis of α-aminophosphonates through Kabachnik–Fields reaction.

Effect of Nitrogen Doping on Structural and Optical Properties of TiO2 Nanoparticles

“…Further observation by SAED Figure 5(d) and in Figure 5(h) confirmed that the NPs are well crystalline in nature with tetragonal anatase structure. Figure 5(b and (f)) shows the lattice fringes of the material with inter planar spacing d spacing 0.25 and 0.26 nm matches well (101) plane of anatase TiO 2 crystal structure [ 3,19 ]…”

“…[ 1,2 ] It has been proven that the desired photocatalytic properties of TiO 2 were achieved by fulfilling requirements in terms of high crystallinity, unique morphology, and mixed‐phase composition, the potential of oxidizing and reducing under suitable irradiation. [ 3 ] Thus, because the band gap for the crystalline anatase phase TiO 2 is 3.2 eV with the absorption edge at near‐UV light, when this semiconductor is exposed to near‐UV light, the electrons in the valence band are excited to the conduction band produced an electron (e − ) and hole (h + ), generating a redox potential. [ 4 , 5 ]…”

Improvement of low-temperature NH3-SCR catalytic performance over nitrogen-doped MOx–Cr2O3–La2O3/TiO2–N (M = Cu, Fe, Ce) catalysts

“…The characteristic peak at around 397.9 eV is attributed to O–Ti–N structures generated upon the replacement of O atoms in the TiO 2 network. 38 Furthermore, the peak at 400.8 eV can be assigned to O–Ti–O–N bonds, indicating that N atoms doped in the TiO 2 lattice in the interstitial sites. 39 From the XPS results, the existence of compounds O–Ti–N and O–Ti–O–N confirms that nitrogen atoms have been doped into the lattice of TiO 2 .…”

Recent Advances in the Synthesis of α‐Aminophosphonates: A Review

“…Using a similar approach, nitrogen-doped TiO 2 ðN À TiO 2 Þ solid-acid nanocatalysts were prepared and evaluated for the synthesis of novel α-Aminophosphonates, starting from pyrazolealdehyde, triethyl phosphite and various substituted anilines under microwave irradiation (420 W) for (10-15 min). [82] The concentration of the catalyst and the effect of different solvents were investigated. The results showed that 12 mol% of catalyst and solvent-free media were the best conditions to carry out the reaction by considering the yields of the desired products.…”

“…Using a similar approach, nitrogen‐doped solid‐acid nanocatalysts were prepared and evaluated for the synthesis of novel α‐Aminophosphonates, starting from pyrazolealdehyde, triethyl phosphite and various substituted anilines under microwave irradiation (420 W) for (10–15 min) [82] …”