Noble-Free Nanophotocatalyst of Ti_xFe_yLa_mO_z for Efficient Photocatalytic C–N Cross-Coupling Reactions under Visible Light

Abstract

Nanophotocatalysts are applied for different applications, and their usage has been enhanced remarkably since a decade. On the other hand, cross-coupling reactions of C−N bonds have found increasing popularity for coupling derivatives of organic compounds such as aniline using diverse catalysts. Nanoheterogeneous photocatalysts can offer suitable platforms for the C−N coupling of aniline derivatives. However, the design of a photocatalyst on the nanoscale with remarkable activity and selectivity, made of noble-free elements, is highly welcome. In this study, the half-filled electronic configuration and shallow trapping properties of Fe were employed to reduce the energy band gap of the system. Moreover, the large ionic radius of lanthanide leads to large surface activity. Thus, bi-and trinuclear nano-oxide nanophotocatalysts were synthesized based on the titanium, iron, and lanthanide elements (Ti x Fe y O z , Ti x Fe y La m O z ) to obtain logically designed photocatalysts with high selectivity, durability, and operation speed under visible light. In addition, designing photocatalysts in the nanoscale was the ultimate target of this study to use the highest benefit of the nanoscale, which is high surface activity. The developed nanophotocatalysts were used for coupling aniline and its 10 derivatives under visible light. The mechanism of the migration of electrons and the C−N reaction was also investigated in detail. In addition, both obtained nanophotocatalysts were applied in five different solvents and eight different conditions so the best condition for the reaction could be determined. Furthermore, the photocatalytic mechanism was studied in detail. The final nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), inductively coupled plasma mass spectrometry (ICP-MS), Brunauer−Emmett−Teller (BET) surface activity, Barrett−Joyner− Halenda (BJH) method, UV−vis spectroscopy, photoluminescence emission spectra, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), NMR spectra, mass spectra, and CHN elemental analysis. Both nanocomposites exhibited high photocatalytic activities in coupling aniline and its derivatives under visible light. However, the Ti x Fe y La m O z nanophotocatalyst showed a higher activity (90% conversion to obtain 2,4 dinitro-n-phenylaniline) than the Ti x Fe y O z nanophotocatalyst (68% conversion to obtain 2,4 dinitro-n-phenylaniline), which is mainly due to its higher surface activity because of its lanthanide content.

Encapsulation of TixFeyLamOz nanoparticles into NH2-MIL-125(Ti) to fabricate a promising photocatalyst for the C–N coupling reaction

“…S3 †). 17 The overall crystallite structure for both samples showed the anatase phase, which is one of the phases of TiO 2 . However, in each case, the peak related to the corresponding elements can be observed and is illustrated in the figure (Fig.…”

“…16 To produce a photocatalyst with the ability to operate under visible light, different methods exist, among which doping TiO 2 with metals can transfer the active area of TiO 2 from ultraviolet light to visible light. It is even possible to increase the active surface of modified TiO 2 using lanthanides, 17 which can be performed by a co-doping method, and this consequently increases the photocatalytic reactivity. [18][19][20] Metal-organic frameworks (MOFs), 21 due to their large internal surface area, 22 flexibility in designing the active sites, 23 chemical alteration, 24 pore structure, and high metal content, 25 provide valuable opportunities to design compounds with multiple applications.…”

“…The encapsulation of noble-free nanoparticles in a MOF is a relatively new branch in the MOF family, and can be performed for those MOFs that exhibit excellent shape and selective catalytic performance in organic reactions. 38,41 To achieve this, NH 2 -MIL-125(Ti) was chosen to be modified by a tri-nuclear nanoparticle of Ti x Fe y La m O z , which we recently obtained in our group 17 and used in a photocatalytic C-N cross-coupling reaction under visible light, with Ti x Fe y La m -O z @NH 2 -MIL-125 prepared by the impregnation method. The obtained composite illustrated the ability to successfully synthesize the product in a short time without using any basis, with a high product yield and stability over several cycles.…”

“…16 To produce a photocatalyst with the ability to operate under visible light, different methods exist, among which doping TiO 2 with metals can transfer the active area of TiO 2 from ultraviolet light to visible light. It is even possible to increase the active surface of modified TiO 2 using lanthanides, 17 which can be performed by a co-doping method, and this consequently increases the photocatalytic reactivity. 18–20…”

Unveiling the Mechanisms of Enhanced Photocatalysis: A Comprehensive Study on Metal–Organic Framework Encapsulation Strategies and the Synthesis of Pt@MOF for Efficient C–N Coupling Reactions

“…This discrepancy highlights that a photocatalyst’s efficiency is not solely dependent on its platinum content despite its renowned catalytic capabilities. Instead, efficiency is influenced by numerous references factors including surface area, light absorption, the presence of catalytic centers for producing specific species, and the recombination of electrons. , Pt 2–2 @MOF outperformed Pt 3–3 @MOF across these critical parameters, underscoring the significance of not just the quantity of catalytic material but also the quality of the photocatalyst’s design and the synergy among its components. The superior performance of Pt 2–2 @MOF can be attributed to its optimized integration of key elements such as 2-aminoterephthalic acid, the Ti ion, and the Pt complex.…”