Nitrogen doped TiO2/Graphene nanofibers as DSSCs photoanode

Photocatalytic Reduction of CO2 with N-Doped TiO2-Based Photocatalysts Obtained in One-Pot Supercritical Synthesis

“…On the other hand, it is not surprising that the light absorption spectra of composites and supports (CNT or rGO) are similar since the composite surface is not fully covered with TiO 2 . The particular shape of absorbance curves for carbon supports and composites has also been observed in other works dealing with traditional synthesis of N-doped TiO 2 /carbon support composites [ 39 ]. Precisely, this very special form prevents us from calculating the band gap energies of composites with the same graphical method described in reference [ 6 ], as happened in previous works [ 8 , 9 ].…”

“…When N content increased (as in N 2 /TiO 2 /rGO), crystallite size decreased. Just as happened with CNTs, the main characteristic peak of graphene at about 25° is shadowed by the main peak of anatase TiO 2 , surely due to the homogeneous dispersion of TiO 2 on rGO [ 39 ].…”

“…The relatively weak signal of the C-O groups indicates that most of the GO oxygen is reduced during the synthesis of catalysts in supercritical medium [ 51 ]. The first peak also appears in the N-doped TiO 2 /rGO composite, proving that the structure of graphene remains after the synthesis of composite catalyst [ 39 ]. Moreover, the two small peaks at 286.3 and 288.7 eV in TiO 2 /rGO composite can be associated with C-O and C=O bonds in support, respectively.…”

“…Regarding N-doped TiO 2 /carbon support composites synthesized in supercritical medium, only N-doped TiO 2 /rGO composites have shown higher photocatalytic activity (but not methane selectivity) than similar composites synthesized with traditional methods [ 30 ]. In this case, the main reason is undoubtedly the extraordinarily good ability of the composites obtained in this work to absorb visible light compared to conventional N-doped TiO 2 /rGO materials [ 39 ]. The poorer photocatalytic activity of N-doped TiO 2 /CNT composites seems to be derived from the smaller crystallite size [ 32 ] and BET area [ 34 ] of the materials obtained in this work, in contrast to those synthesized with traditional methods.…”

Electrochemical Impedance Investigation of Dye-Sensitized Solar Cells Based on Electrospun TiO2 Nanofibers Photoanodes

“…Furthermore, this technique could be applied to fabricate 3D networks from TiO 2 NFs [ 25 ] or nanocomposites Zr/Ag /TiO 2 [ 26 ], and applied for variable applications, including water treatment [ 27 ], photocatalysis [ 28 ], solar energy [ 29 ], and different multifunctional applications [ 30 ]. Additionally, many chemical treatments were reported to improve the efficiency of TiO 2 , such as surface modification [ 31 ], metal doping [ 32 ], or non-metal doping [ 33 , 34 ]. The N-doping strategy could enhance the optical characteristics of the utilized semiconductor in addition to improving the photo-generated electrons’ mobility via decreasing the charge recombination as well as shifting the flat-band voltage of the conduction band, which has a significant impact on both the obtained current (J SC ) and voltage (V OC ) [ 35 ].…”