A study on the potential application of natural phosphate in photocatalytic processes

Natural Phosphate Supported Titania as a Novel Solid Acid Catalyst for Oleic Acid Esterification

“…The second mass loss at 432 °C can be attributed to the decomposition of residual organic matter, mainly the nonreactive titanium precursor and the elimination of the OH groups attached to the surface of TiO 2 nanoparticles. 39 The UV−visible spectra of TiO 2 and TiO 2 (10)/NP samples calcined at different temperatures are depicted in Figure S2. The calcined samples show similar and very strong absorption bands in the 200−350 nm wavelength regions, centered around 215, 270, and 307 nm.…”

“…The calcined samples show similar and very strong absorption bands in the 200−350 nm wavelength regions, centered around 215, 270, and 307 nm. The first band was attributed to Ti(IV) species in tetrahedral coordination, 39,42 while the other adsorption bands could be assigned to Ti atoms with octahedral symmetry or to partially polymerized Ti species, which contain Ti−O−Ti bonds. 43−45 We note that the obtained results are in good agreement with those reported by Hidalgo-Carrillo et al 39 The N 2 adsorption−desorption isotherm of TiO 2 (10)/NP catalyst corresponds to a type IV isotherm according to the IUPAC classification and exhibited an H3 hysteresis loop appearing at the high P/P 0 region of 0.5−0.96, suggesting the presence of very homogeneous slit-shaped mesopores (Figure 3).…”

“…The first band was attributed to Ti(IV) species in tetrahedral coordination, 39,42 while the other adsorption bands could be assigned to Ti atoms with octahedral symmetry or to partially polymerized Ti species, which contain Ti−O−Ti bonds. 43−45 We note that the obtained results are in good agreement with those reported by Hidalgo-Carrillo et al 39 The N 2 adsorption−desorption isotherm of TiO 2 (10)/NP catalyst corresponds to a type IV isotherm according to the IUPAC classification and exhibited an H3 hysteresis loop appearing at the high P/P 0 region of 0.5−0.96, suggesting the presence of very homogeneous slit-shaped mesopores (Figure 3). As expected, incorporation of TiO 2 on NP results in a significant increase in surface area of the prepared catalyst (35.55 m 2 /g) compared to the NP alone (2 m 2 /g) or pure TiO 2 prepared under the same conditions as TiO 2 (10)/NP (30 m 2 /g).…”

“…Natural phosphate supported titania was prepared by following the same procedure described by Hidalgo-Carrillo et al 39 Briefly, 10 g of NP was introduced in a 250 mL flask containing 60 mL of 2-propanol and appropriate amounts of titanium isopropoxide accordingly to prepare nominal contents of 2.5 wt % (0.925 mL), 5 wt % (1.85 mL), and 10 wt % (3.7 mL) (expressed as grams of TiO 2 per gram of catalyst). Afterward, a mixture of water/2-propanol (1/10, v/v) was added and the resulting mixture was stirred for 30 min.…”

Strontium delivery systems based on bacterial cellulose and hydroxyapatite for guided bone regeneration

“…6), P 2p signal is that much more sensitive to oxidation states; however, P 2p signal for Sr containing samples overlaps with Sr 3d core level signal, therefore P 2s spectra have been considered in these two cases, although it is less sensitive to distinguish different oxidation states. BC/CaHA sample exhibits a main P 2p 3/2 peak (solid line) at 132.7 eV, which is ascribed to phosphate groups in apatites (Hidalgo-Carrillo et al 2010;Ohtsu et al 2012). In the case of samples containing Sr, P 2s spectra showed in both cases a main signal centered at ca.…”