The solid solutions (V 1-x W x )OPO 4 with β-VOPO 4 structure type (0.0 Յ x Յ 0.01) and α II -VOPO 4 structure type (0.04 Յ x Յ 0.26) were obtained from mixtures of V V OPO 4 and W V OPO 4 by conventional solid state reactions and by solution combustion synthesis. Single crystals of up to 3 mm edge length were obtained by chemical vapor transport (CVT) (800 Ǟ 700°C, Cl 2 as a transporting agent). Single crystal structure refinements of crystals at x = 0.10 [a = 6.0503(2) Å, c = 4.3618(4) Å, R 1 = 0.021, wR 2 = 0.058, 21 parameters, 344 independent reflections] and x = 0.26 [a = 6.0979(2) Å, c = 4.2995(1) Å, R 1 = 0.030, wR 2 = 0.081, 21 parameters, 346 independent

The solid solutions (V1‐xWx)OPO4 with β‐VOPO4 structure (0.0 ≤ x ≤ 0.01) and αII‐VOPO4 (tetragonal space group P4/n, Z = 2) structure (0.04 ≤ x ≤ 0.26) are obtained from mixtures of VOPO4 and WOPO4 by conventional solid state reaction in the presence of Cl2 as mineralizer (silica ampoule, 800 °C, 7 d).

The feed grade monocalcium phosphate monohydrate, Ca(H2PO4)2·H2O was prepared by the reaction of CaCO3 and H3PO4 at elevated temperature in aqueous solution. The obtained precipitates were characterized by powder X-ray diffraction, infrared spectroscopy (FTIR), and thermal analysis (TG, DTA) techniques. The chemical composition of final products was evaluated by analysing the phosphorus and calcium content in the samples.

The nano-mixed oxides CeO2-TiO2 was synthesized by gel combustion method using polyvinyl alcohol as fuel and mixtures of titanium trichloride and cerium(IV) nitrate at a relatively low calcination temperature of 550°C for 2 h. The prepared CeO2-TiO2 nanoparticles with a specific area of 65.70 m2 g−1 were dispersed in polyurethane matrix in different concentration conditions from 0.0 to 1.5 wt% to study ultraviolet durability following HONDA HES D 6501-97 standards. After 400 h of testing in the QUV accelerate weathering tester, the thin film containing 1 wt% CeO2-TiO2 nano-mixed oxides has presented the noticeable capacity for absorbing ultraviolet light by only 6.8 g.u change in specular gloss at 60° and ΔE = 3.66 in color difference.

In the present article, the adsorbent prepared from laterite with lanthanum and cerium oxides (La2O3-CeO2/laterite (LCL)) was efficiently employed for the removal of arsenite and fluoride from an aqueous environment. The obtained materials were characterized by XRD, SEM, and nitrogen adsorption/desorption. The synthesized LCL exhibited a high adsorption capacity towards arsenite (As(III)) and fluoride. The adsorption of both analytes on LCL, which was well-fitted to a pseudo-second-order equation, was found to be kinetically fast in the first 20 minutes and reached equilibrium at around 180 minutes. Weber’s intraparticle diffusion model in multilinearity using the piecewise linear regression combined with Akaike’s criteria was addressed. The adsorption capacities of LCL calculated from Langmuir’s isotherm model were found to be 67.08 mg·g-1 for arsenite and 58.02 mg·g-1 for fluoride. Thermodynamic parameters presented an endothermic nature of arsenite adsorption but an exothermic nature for fluoride and a negative Gibbs free energy for the spontaneous process of arsenite or fluoride adsorption at the studied temperature range. The excellent adsorption performance and stability make the composite of laterite and La-Ce binary oxides an alternative efficient and cheap adsorbent for the removal of arsenite and fluoride in an aqueous solution.