Hydrothermal Synthesis of Mesoporous Nanocrystalline Tetragonal ZrO2 Using Dehydroabietyltrimethyl Ammonium Bromine

Abstract

aMesoporous nanocrystalline tetragonal zirconias were successfully synthesized through a hydrothermal method using a novel bioresourcederived quaternary ammonium salt, dehydroabietyltrimethyl ammonium bromine (DTAB), as a templating agent. The templating agent provides a surface area (242.02 m 2 /g), high pore volume (0.53 cm 3 /g), and large average pore diameter (7.65 nm), which suggests that DTAB is a good candidate for mesostructure synthesis. The hydrothermal treatments give the materials improved thermal stabilities because of the generation of tetragonal nanocrystallites that are more stable than the bulk amorphous ones in the hydrothermal process. However, because of the absence of stabilizers, the sizes of the crystallites of the as-synthesized sample increase gradually with increasing calcination temperature. As the crystalline size of the sample rises to 25 nm, the nanocrystallites become too large to integrate well together, causing the well-organized mesostructure to collapse.

Tailoring the surface area and the acid–base properties of ZrO2 for biodiesel production from Nannochloropsis sp.

“…The presence of low-angle diffraction peaks at a 2θ range from 0.06° to 0.80° indicates that both ZrO 2(P123) and ZrO 2(CTAB) exhibited well-organized mesopore structures after calcination at 500 °C (Fig. 1a,b) 44,45 . Figure 1c shows the wide-angle XRD diffractogram of bare ZrO 2 with reflection peaks at 2θ = 30.2° (011), 35° (110), 50.3° (112), and 60.1° (121) that corresponded to tetragonal ZrO 2 (t-ZrO 2 ; ICDD: 98-015-7619).…”