The interplay between dopant and a surface structure of the photocatalyst – The case study of Nb-doped faceted TiO2

Insight into (Electro)magnetic Interactions within Facet-Engineered BaFe12O19/TiO2 Magnetic Photocatalysts

“…The introduction of SiO 2 prevents electron transfer, resulting in higher photocatalytic activity observed for the composite material. This material shows the highest activity within prepared composites, in accordance with {1 0 1} being exceptionally suitable for phenol degradation, as shown before when compared to the TiO 2 P25 standard . However, such significantly negative electronic interactions with BaFe 12 O 19 imply that other composite systems, with maximized {1 0 1} content and minimized electron transfer, might be better suited for practical application.…”

“…Nevertheless, it can be noted that in the case of the 50% TiO 2 {0 0 1} sample, some loss of the TiO 2 was observed during the separation process, as shown in Figures S4 and S5 in the Supporting Information. It can result from the large scattering and absorption coefficients of these particles, reported previously …”

“…Photocatalysis presents a promising but challenging solution for various environmentally relevant processes, such as the generation of solar fuels and the purification of water and gas streams. − However, large-scale application of heterogeneous photocatalysis still requires solving some challenges related to enhancing semiconductor activity and decreasing the recombination of photogenerated charge carriers participating in the redox reactions on the photocatalyst surface. In recent years, this has led to great attention focused on improving photocatalytic activity by designing and synthesizing different photocatalytic materials. − More recently, studies have shown that photocatalytic processes might be optimized by alternating the exposition of the specific crystal planes. − This is strictly connected with the anisotropy of the photocatalyst electronic structure, which depends on the direction inside the crystal structure, the specific arrangement of atoms at the interface, and the nature of the interface itself. − Ultimately, the alternation of the photocatalyst morphology and exposed crystal facet is recognized as the state-of-the-art approach to optimize the performance in photocatalytic reactions. Another important technological issue in the application of such photocatalytic nanostructures is their separation after the reaction, which is especially important for water treatment processes.…”

Fine-Tuning the Photocatalytic Activity of the Anatase {1 0 1} Facet through Dopant-Controlled Reduction of the Spontaneously Present Donor State Density

“…Photonic efficiency of phenol degradation (ζ) was calculated for the 5 min process as the ratio between degraded phenol molecules and the amount of UVA (310–380 nm) photons introduced to the reactor, which can excite the TiO 2 photocatalyst: ζ = r 5 min I 0 × 100 % where r 5 min is the rate of phenol disappearance at 5 min of the process (μmol·min –1 ) and I 0 is the incident UVA photon flux that reaches the reactor border (μmol·min –1 ). I 0 is estimated to be 24.937 μmol·min –1 , based on the controlled UVA flux intensity, as well as lamp emission spectrum and flux distribution at the reactor border, which for the used setup is reported in detail elsewhere . For all experiments, the same lamp-reactor configuration was used.…”

Constructing Sequential Type II Heterojunction CQDs/Bi2S3/TiNbO Photoanode with Superior Charge Transfer Capability Toward Stable Photoelectrochemical Water Splitting

“…Zhong et al reported that Nb-doping caused an increase in the electron concentration and a shift in the energy band structure of TiO 2 , thereby resulting in a decrease in the bandgap value. Additionally, Dudziak et al found that using Nb as a donor was advantageous because of its well-defined shallow properties and the ease with which it could be doped into an anatase structure. These results demonstrated that Nb doping is beneficial for improving the overall properties of TiO 2 .…”