1. Synergy of copper and graphene for visible-light promoted photochromism and photocatalysis in TiO2 nanoparticles
- Author
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Tobaldi, David Maria
- Abstract
Multifunctional materials working under solely visible-light are expected to play a significant role in photo-electronics, in particular photo-switches, photo-optical sensors, smart windows, displays, optical storage memories, and self-cleaning materials. We have modified the surface of a versatile semiconductor material (TiO2) with a noble metal (copper) and high crystalline quality graphene. Exploiting the ability of a semiconductor to generate an exciton upon excitation, a multifunctional material working with visible-light and showing photochromic and photocatalytic activity was engineered. Photochromic and photocatalytic tests were assessed using a white light emitting diode (LED). Specimens modified with copper (1 mol%) and graphene (0.5 wt%) exhibited faster photochromism (3 times), and more stable photoswitching compared to standard Cu-TiO2 photochromic material. The same material also displayed visible-light induced photocatalytic activity in the gas-solid phase (degradation of benzene, one of the most hazardous pollutants found indoor) superior to unmodified titania (3.00 times higher). Copper acted as the chromophore (and visible-light absorber for the photocatalytic reaction). Furthermore, the electronic transport is enhanced in the graphene/TiO2 hybrids, increasing the lifetime of the photogenerated exciton. Our data highlights the unique characteristics of that material, and the suitability for multi-purpose applications in the field of environmental monitoring and remediation, and smart materials technologies.
- Published
- 2019
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