Heterostructured TiO₂/SiO₂/γ-Fe₂O₃/rGO Coating with Highly Efficient Visible-Light-Induced Self-Cleaning Properties for Metallic Artifacts

Abstract

A novel nanohybrid composite of TiO 2 , SiO 2 , γ-Fe 2 O 3 , and reduced graphene oxide (TiO 2 @Si:Fe:rGO) is fabricated by the sol–gel method. The properties of the coated film were examined by structural and self-cleaning analyses using simulated discoloration/soiling and roofing tests. The fabricated transparent TiO 2 @Si:Fe:rGO composite showed excellent photoactivity and wettability, behaving well in self-cleaning applications. The addition of SiO 2 improved the crystalline structure and surface hydroxylation of TiO 2 nanoparticles. γ-Fe 2 O 3 decreased the recombination rate of e – /h + pairs, and significantly improved photocatalytic activity under visible light. Moreover, rGO sheets as excellent electron acceptors and transporters also reduced recombination, as well as affected wettability, achieving superhydrophilicity under irradiation. The coated substrate showed excellent resistance to simulated acid rain and significantly preserved the substrate from soiling in roofing tests.

A study on the preparation and performance of a graphene-supported, Ce ion-doped, high-efficiency, magnetic TiO2 photocatalyst

“…16 In fact, SiO 2 , as a magnetic isolation material, can be used as a protective film to avoid interactions between the magnetic core and the TiO 2 coating. [17][18][19] Meanwhile, graphene is a two-dimensional nanomaterial with high specific surface area and high conductivity. 20,21 It can improve the migration efficiency of photogenerated carriers, and therefore, the recombination of photogenerated carriers can be effectively suppressed.…”

Manipulating the Low-Energy Photons by an Upconversion Fluorescent Hybrid Photocatalyst for Water Oxidation

“…Attributed to the P doping, the photoabsorption edge of In 2 S 3 nanosheets was extended from 400 to 550 nm by the hybridization of P 3s, P 3p, and S 3p orbitals . Furthermore, the TiO 2 @Si/Fe/rGO film exhibited enhanced photoabsorption compared to pristine TiO 2 owing to the reduced charge recombination by rGO . Although the above strategies have realized red-shifting of the photon absorption, using infrared light in PEC water splitting is still a challenging task. − …”

“…10 Furthermore, the TiO 2 @Si/Fe/rGO film exhibited enhanced photoabsorption compared to pristine TiO 2 owing to the reduced charge recombination by rGO. 11 Although the above strategies have realized red-shifting of the photon absorption, using infrared light in PEC water splitting is still a challenging task. 12−14 Lanthanide-containing fluorescence materials are promising materials for regulating light absorption in the infrared region.…”

Study on Photodegradation Activity of Fe3O4@SiO2@TiO2-Ce/rGO Magnetic Photocatalyst

“…Although many research groups have developed magnetic core-shell catalysts containing TiO2 that can be quickly separated from sewage [14,15] . However, The magnetic core may be reduce the photocatalytic efficiency [16] , To resolve this problem, SiO2 can be applied as a barrier layer to form Fe3O4@SiO2 which will not allow the interaction between the magnetic core and the TiO2 coating [17][18][19] . Meanwhile, Graphene is a twodimensional nanomaterial with high specific surface area and high conductivity [20,21] , it can improve the migration efficiency of photogenerated carriers, Therefore, the recombination of photogenerated carriers can be effectively suppressed.…”