Removal of dyes by photocatalytically active curcumin-sensitized amorphous TiO2 under visible light irradiation

Photosensitive Hybrid Nanostructured Materials: The Big Challenges for Sunlight Capture

“…As mentioned above, a current trend is a search for effective natural dyes extracted from plants or microorganisms. Recent reports on this kind of dyes as TiO 2 sensitizers include curcumin, a simple conjugated diketone found in turmeric (Curcuma longa) [70], and anthocyanin [71]. In several works, natural dyes are extracted from the species containing them, e.g., chlorophyll and flavonoid from parsley leaves and turmeric roots [72], chlorophyll and other pigments from cyanobacteria [73], anthocyanin-rich mixture from Vaccinium meridionale Swartz (Andean blueberry) [74], extract from Picramnia sellowii tree [75], or Chlorella pyrenoidosa, a green unicellular alga used as both sensitizer and biotemplate for Fe 3 O 4 -TiO 2 composites [76].…”

Structural analysis and dye removal behavior of amorphous titania embedded poly(vinyl butyral) hybrid fiber

“…Furthermore, organic–inorganic hybrid structures driven by transition metal titanium dioxide (TiO 2 ) are also effective in the field of adsorption and photodegradation for organic pollutants. 6 Although crystalline TiO 2 is suitable for photocatalytic reactions due to its low toxicity, chemical–thermal stability, and good resistance to photo-corrosion, it has several well-known drawbacks, including ineffective utilization of visible and near-infrared light and high recombination of photo-generated charge carriers, which greatly hinder the improvement of its photocatalytic activity. 7 Conversely, amorphous metal oxides have several potential advantages over crystalline phases: 8 they are easier to make at room temperature, with a significantly larger surface area, and the ability to have a variety of chemical compounds doped or embedded into their matrices.…”

“…Buddee et al developed curcumin-sensitized amTiO 2 for the successful photodegradation of MB dye. 6 Later, Wang et al showed that amTiO 2 was faster than crystalline TiO 2 for the visible-light-induced photodegradation of rhodamine B (Rh-B), implying that amTiO 2 was a good mediator for electron transfer from excited dyes to oxygen. 10 They stated that the synergistic dye degradation dynamics were mainly controlled by the higher surface area of amTiO 2 rather than crystallinity.…”

Photoactive Thin-Film Structures of Curcumin, TiO2 and ZnO

“…The point of improvement with these oxides is the fact that the photocatalytic activity is limited to the UV range only, due to their wide bandgaps (ZnO: 3.3 eV, TiO 2 : 3.2 eV) [ 40 , 41 ]. Interestingly, there are few promising reports showing that curcumin may be used to sensitize/activate TiO 2 towards longer wavelength (420–580 nm) absorption [ 42 , 43 ], or loaded in ZnO nanoparticles to enhance the antibacterial and anticancer properties [ 44 ]. Moreover, we have succeeded in tailoring the optical bandgap of TiO 2 thin films by insertion of monomolecular organic (Cur or hydroquinone) layers into regular SL structures using ALD/MLD, such that the films were activated for visible-light absorption [ 30 , 45 ].…”