Multifunctional TiO 2 /Fe x O y /Ag based nanocrystalline heterostructures for photocatalytic degradation of a recalcitrant pollutant

Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

“…The experimental results demonstrated that the TiO2NRs/FexOy/Ag nanostructure, with Ag nanoparticles of 12 nm in size, was 1.9 times faster than the commercial TiO2 P25 and 1.5 times faster than the TiO2NRs. Such an enhancement has been accounted for by the presence of Ag nanoparticles that enhance visible light photoactivity due to their peculiar plasmonic properties (Figure 9) [20]. These materials can be easily removed and recycled by applying an external magnetic field.…”

“…A possible strategy is based on visible-light-active, multifunctional nanostructures, which show great promise as efficient and recyclable photocatalysts for environmental remediation. Petronella (Figure 9) [20]. These materials can be easily removed and recycled by applying an external magnetic field.…”

“…Such a PRET phenomenon is thought to enhance the electric field in a well-defined location resulting in a rapid formation of e − /h + pairs [61-64]; • far-field effect: an efficient scattering can be mediated by surface plasmon resonance, which Several papers demonstrate a great improvement in visible-light-driven photocatalysis upon deposition of Ag and Au nanoparticles onto TiO 2 nanostructures [2,18,20,[56][57][58]. However, the mechanism behind such an enhancement is still under debate.…”

“…In general, the strategies proposed to increase the lifetime of e − /h + and improve the photoactivity of TiO 2 in the visible range can be classified as follows: (i) introduction of red-ox couples or noble metals at semiconductor particle surface; (ii) doping with metal of non-metal atoms; (iii) coupling with narrow band gap semiconductors able to absorb visible light. Among the plethora of approaches proposed in the literature so far [1,2,[18][19][20], hybrid nanocrystals, i.e., nanostructured materials formed by two or more components, each characterised by peculiar physical properties, surface chemistry and morphology, combined together into one nano-object, hold great promise for the development of multifunctional nanocatalysts. Indeed, hybrid nanocrystals offer the opportunity to merge in one material photocatalytic semiconductors and plasmonic structures, or semiconductors and oxides with a different energy gap, or semiconducting and magnetic oxides, resulting in countless possible combinations [2,18,[20][21][22][23][24][25].…”

“…Among the plethora of approaches proposed in the literature so far [1,2,[18][19][20], hybrid nanocrystals, i.e., nanostructured materials formed by two or more components, each characterised by peculiar physical properties, surface chemistry and morphology, combined together into one nano-object, hold great promise for the development of multifunctional nanocatalysts. Indeed, hybrid nanocrystals offer the opportunity to merge in one material photocatalytic semiconductors and plasmonic structures, or semiconductors and oxides with a different energy gap, or semiconducting and magnetic oxides, resulting in countless possible combinations [2,18,[20][21][22][23][24][25]. Besides the photoactivity under visible light irradiation, hybrid nanocrystals could also provide spatial separation of e − /h + , thus improving the lifetime of the excited state and an opportunity to magnetically recover the photocatalysts or activate biocidal function even in the dark.…”