Synergistic effect of {101} crystal facet and bulk/surface oxygen vacancy ratio on the photocatalytic hydrogen production of TiO2

Core–shell defective TiO2 nanoparticles by femtosecond laser irradiation with enhanced photocatalytic performance

“…However, surface defects are more efficient at trapping and separating photogenerated electron–hole pairs, whereas bulk defects can act as recombination centers for such photogenerated charge carriers. 62–64 The Raman and XPS spectra show the oxygen vacancies and Ti 3+ species formation on the surface, suggesting that laser modified TiO 2 can potentially exhibit better photocatalytic performance. To test this, the breakdown of the MB dye was compared with untreated TiO 2 and TiO 2 -90 as the photocatalytic materials.…”

A reclaimed piezoelectric catalyst of MoS2@TNr composites as high-performance anode materials for supercapacitors

“…59 During the piezoelectric catalytic degradation process, the active hydrogen rapidly combines with an O atom on the catalyst surface to form an OHspecies that would later become a H 2 O molecule, leading to the generation of an oxygen vacancy. 66,67 Compared to the peak tting results of the O 1s energy spectrum, the amount of lattice oxygen in the reclaimed catalyst obviously decreased, while the peak area at the binding energy of 532.5 eV corresponding to the adsorbed oxygen showed a great increase. This further conrmed the formation of oxygen vacancies due to the ion exchange reaction at the interface during the piezoelectric catalytic reactions.…”

“…68 Positron annihilation lifetime spectroscopy (PALS) was considered to be an effective and sensitive technique to qualitatively study and analyze the oxygen vacancies in the catalyst samples at low concentrations. 66,67 Once the positrons were injected into the samples, they preferentially diffused to the low electron density regions such as microvoids, mono-vacancies and vacancy clusters, and were then thermalized and annihilated by electrons, simultaneously emitting g rays. Usually, in a disordered system, the small mono vacancies or oxygen vacancies can lower the electron density and then decrease the annihilation rate; thus, the lifetimes of positrons that contain the information about defects in the samples can be obtained by the positron annihilation tests.…”

Tailoring the exposed facets of anatase titania and probing their correlation with photocatalytic activity – an experimental and statistical study

“…3 The number of oxygen vacancies thus formed plays a decisive role in the formation of titania terminated with reactive facets modifying its physicochemical properties and greatly increasing its efficiency. 4–6…”

“…3 The number of oxygen vacancies thus formed plays a decisive role in the formation of titania terminated with reactive facets modifying its physicochemical properties and greatly increasing its efficiency. [4][5][6] Several recent studies have theoretically and experimentally proven that anatase titania exposed with highly reactive facets such as {111}, {010}, {110}, and {001} is related to the intensity of surface-coordinated titanium centres. An increase in the Ti-O-Ti bond angle is also observed during highly reactive facet formation, which leads to the emergence of new reactive Ti and O centres.…”