Highly photoactive 2D titanium dioxide nanostructures prepared from lyophilized aqueous colloids of peroxo-polytitanic acid

The relationship between microstructure and photocatalytic behavior in lanthanum-modified 2D TiO2 nanosheets upon annealing of a freeze-cast precursor

“…La-modied TiO 2 nanosheets were prepared by a freeze-casting method [24][25][26][27] using aqueous colloids of peroxo-polytitanic acid (PPTA) and La(NO 3 ) 3 (see Scheme 1). In a typical experiment, 4.80 g of titanyl sulfate was dissolved in 150 mL of distilled water at 35 C (step 1).…”

“…Aer freeze-casting, a yellowish "granule-like" lyophilized precursor (lyophilized cake) was isolated (step 7). 23,25 The lyophilized precursor labeled Ti_La_LYO was further heat-treated under air at 500, 650, 800 and 950 C for 1 h in each case (with rate 3 C min À1 ), and four new samples denoted as Ti_La_500, Ti_La_650, Ti_La_800 and Ti_La_950 were obtained (Scheme 1).…”

“…In previous research, we found that the binuclear adducts were formed by mixing TiOSO 4 as the source of Ti 4+ and H 2 O 2 (Scheme 1). 25,27 These adducts contain the planar Ti-O-O-Ti grouping where the Ti atoms are bridged by m-oxygen and two m-peroxy groups (Fig. 3a).…”

Photocatalytic degradation of bisphenol A induced by dense nanocavities inside aligned 2D-TiO2 nanostructures

“…3). In the case of heat treatment from 500 to 950 °C, the N 2 adsorptiondesorption isotherm was found to be typical of the H3-type hysteresis [60] loops in IUPAC classification [61] indicating that the TiO_LYO_500, TiO_LYO_650, TiO_LYO_800 and TiO_LYO_950 materials consist of platelike particles [51]. No heat treatment may result in a negligible extent of bond rupture, forming lamellar sheets thicker than the platelike crystals obtained at higher treatment temperatures.…”

“…Detailed BET/BJH hysteresis graphs for cryo-lyophilised samples can be found in our recent publication [56]. Samples heated at 500, 650, 800 and 950 °C exhibit obvious hysteresis behavior, indicating that the products are mainly mesoporous according to IUPAC classification [57].…”