The photocatalytic performance of Fe inserted in Nb2O5 obtained by microwave-assisted hydrothermal synthesis: Factorial design of experiments

Photocatalytic performance of Al and Nb‐doped TiO2 nanoparticles prepared by microwave‐assisted hydrothermal method

“…As the pH of the solution increased, there was a decrease in the photocatalytic behavior, that is, the best photocatalytic performance was for the sample at pH 5.0, with 100% discoloration of RhB under UVC irradiation and in 75 min of analysis under alkaline conditions, it is normal for photocatalytic degradation to decrease due to deprotonation of the -COOH group, different from what happens under acidic RhB conditions, which have a greater amount of H + , favoring the interaction with the oxidant species and consequently improving the photocatalytic performance. 66,67 The amount of catalyst was also verified, as shown in Figure 10B. As there was an increase in the amount of catalyst in 100 ml of RhB, it was found that there was an improvement in the photocatalytic performance, where using 100 mg of ALNBT, it was possible to reach the mark of 100% discoloration in 45 min of analysis, while in 50 mg, it was possible to visualize 100% discoloration in just 75 min.…”

“…The pH used in the tests above was 5, so it was decided to test two more pH values, 7 and 10, as shown in Figure 10A. As the pH of the solution increased, there was a decrease in the photocatalytic behavior, that is, the best photocatalytic performance was for the sample at pH 5.0, with 100% discoloration of RhB under UVC irradiation and in 75 min of analysis under alkaline conditions, it is normal for photocatalytic degradation to decrease due to deprotonation of the –COOH group, different from what happens under acidic RhB conditions, which have a greater amount of H + , favoring the interaction with the oxidant species and consequently improving the photocatalytic performance 66,67 …”

“…The insertion of Al and Nb in TiO 2 caused the formation of defects in the crystal lattice, improving the photocatalytic activity, since the excited electrons may have been trapped in a more efficient way, suppressing the rate of recombination of the photogenerated charge pairs 79 . This usually happens for up to a certain concentration of ions, since high concentrations can lead to rapid recombination of electron–hole pairs, thus decreasing photocatalytic activity 66 …”

“…79 This usually happens for up to a certain concentration of ions, since high concentrations can lead to rapid recombination of electron-hole pairs, thus decreasing photocatalytic activity. 66 To identify the involvement of active species in the photocatalytic process, the scavenger methodology was performed, and the results of the variation curves of RhB dye versus time using different charge scavengers are shown in Figure 11. that AgNO 3 suppresses the e -, thus preventing recombination with the h + , leaving the electrons available to act in the discoloration process.…”

Enhanced photocatalytic degradation of levofloxacin over heterostructured C3N4/Nb2O5 system under visible light

“…Similarly, Nb2O5, a widely studied wide bandgap semiconductor, exhibits high photocatalytic activity and photostability due to its Brønsted and Lewis sites at the surface, which serve as anchoring points for interacting species [ 39 ] [ 34 , [40] , [41] , [42] ]. To extend the absorption spectrum of Nb 2 O 5 beyond UV region it is widely coupled with other semiconductor systems such as Nb 2 O 5 /CuO [ 43 ], Nb 2 O 5 /ZnO [ 44 ], TiO 2 /Nb 2 O 5 [ 45 , 46 ], Nb 2 O 5 /iron [ 47 ] and Nb 2 O 5 /RGO [ 48 ] etc. where heterojunction materials exhibited improved catalytic activity in photo redox reactions.…”