Ti och ch3 2 4

We purchased urea (CH₄N₂O), La(NO₃)₃, dicyandiamideand (99%), and TiCl₄ from Sinopharm Chemical Reagent Co. (Shanghai, China) Ti(OCH(CH₃)₂)₄ and P123 (PEO-PPO-PEO) were purchased by Sigma-Aldrich. The water used throughout all of the experiments was purified using a Millipore system.

The BaTiO₃ samples were synthesized via a hydrothermal method,¹² as illustrated in Scheme 1. As a Ti precursor, the Ti(OCH(CH₃)₂)₄ (≥97% purity, Sigma Aldrich) was added dropwise to 15 mL of ice cold distilled water while being constantly stirred. Upon addition of the Ti(OCH(CH₃)₂)₄, the distilled water became turbid then a white precipitate formed. The reaction mixture was stirred in ice bath for 1 h then at room temperature for a further 2 h to allow the reaction to reach completion. To make up the Ba precursor, an appropriate amount of Ba(OH)₂·8H₂O (≥98% purity, Emsure) was dissolved in 55 mL of distilled water. The exact concentration of each precursor used is specific to the reaction parameter being investigated and is specified in the results and discussion section. The Ba precursor solution was added to the Ti precursor suspension to make up the reaction mixture. The reaction mixture was then transferred to an autoclave where it was sealed and heated. Each reaction mixture was heated at a specific temperature in an oven for 16 h. The white solid that formed in the reaction was collected and washed in a centrifuge at 4500 rpm for 8 min. The solid was washed with diluted HCl once, then with distilled water 3 times. After that, the solid was dried at 80 °C for 12 h in a vacuum oven to obtain BaTiO₃ samples.

All the chemicals used were of reagent-grade and they were used without any further purification. Materials used for synthesis of pure TiO₂ and Ag/TiO₂ were titanium isopropoxide (Ti[OCH(CH₃)₂]₄, 97% Sigma-Aldrich) and Silver nitrate (AgNO₃, 99.9% Sigma-Aldrich) and ethanol (99.5% J.T Baker). All solutions were prepared using deionized water.