Multilayer TiO₂ Inverse Opal with Gold Nanoparticles for Enhanced Photocatalytic Activity

Abstract

Three-dimensional highly ordered multilayer titanium dioxide (TiO2) inverse opal (TIO) structures with two pore sizes were fabricated over a large surface using a self-convective method. The fabricated TIO multilayers were functionalized with gold nanoparticles (AuNPs) by immersing the samples in solution with gold nanoparticles. The photocatalytic activity of TiO2 was enhanced by 85% via plasmonic activation of AuNPs that increased the lifetime of photogenerated holes and electrons. The improved photocatalytic activity was characterized with both UVA and visible light irradiation using an in-house built gas-phase photoreactor.

TiO2 Inverse Opals Modified by Ag Nanoparticles: A Synergic Effect of Enhanced Visible-Light Absorption and Efficient Charge Separation for Visible-Light Photocatalysis

“…In the recent years, photocatalysts based on inverse opal TiO 2 (IP-TiO 2 ) nanostructures have attracted great attention due to their excellent visible-light photocatalytic activities [17][18][19][20][21][22][23][24][25][26]. Without the need of doping, IP-TiO 2 can absorb visible-light due to slow photon effect caused by the multiple light scattering in the periodic inverse opal structure [26,27].…”

“…In the recent years, photocatalysts based on inverse opal TiO 2 (IP-TiO 2 ) nanostructures have attracted great attention due to their excellent visible-light photocatalytic activities [17][18][19][20][21][22][23][24][25][26]. Without the need of doping, IP-TiO 2 can absorb visible-light due to slow photon effect caused by the multiple light scattering in the periodic inverse opal structure [26,27]. In addition, similarly to other types of TiO 2 nanomaterials, the coupling of IP-TiO 2 and metal nanoparticles (NPs), such as Au [26], Ag [28], or Ni [29], can boast several advantages in photocatalysis.…”

“…Without the need of doping, IP-TiO 2 can absorb visible-light due to slow photon effect caused by the multiple light scattering in the periodic inverse opal structure [26,27]. In addition, similarly to other types of TiO 2 nanomaterials, the coupling of IP-TiO 2 and metal nanoparticles (NPs), such as Au [26], Ag [28], or Ni [29], can boast several advantages in photocatalysis. On the one hand, this coupling may enhance the visible-light absorption due to the localized surface plasmon resonance (LSPR) effect of the NPs, thereby improving the light harvesting efficiency of the catalysts.…”

“…On the other hand, the lower Fermi level of noble metals with respect to the conduction band of TiO 2 facilitates the transfer of photogenerated electrons from TiO 2 to the metal. This increases the charge separation, which consequently improves the photocatalytic efficiency [26,30]. Therefore, IP-TiO 2 has emerged as a novel class of nanostructured photocatalysts that is promising for environmental and energy-related applications [17][18][19][20][21][22][23][24][25][26].…”

“…This increases the charge separation, which consequently improves the photocatalytic efficiency [26,30]. Therefore, IP-TiO 2 has emerged as a novel class of nanostructured photocatalysts that is promising for environmental and energy-related applications [17][18][19][20][21][22][23][24][25][26].…”