Rapid Synthesis of Mesoporous Nickel Phosphates under Microwave Assisted Hydrothermal Condition

Mesostructured nickel phosphate (MW-NiPO-2) was rapidly synthesized in the presence of cationic sur- factant by a microwave assisted hydrothermal process. The synthesis parameters, microwave irradiation temperature and time, OH - /P and Ni/P molar ratios of the precursor, were systematically investigated and optimized. The charac- terizations of the materials obtained by the two different procedures, Sol-Gel method and microwave assisted hydro- thermal process, were carried out by ICP, FT-IR, TEM and N2 physisorption. The results show that MW-NiPO-2 can be obtained at relatively low temperature (60℃). When the microwave radiation temperature was 100℃, the mesostruc- tured phase formed in an extremely short period about 0.25 h. Ordered MW-NiPO-2 can be obtained under micro- wave irradiation for 1 h at 100℃, when OH − /P and the Ni/P molar ratios of the precursor are 2.0 and 0.7, respectively. In contrast, it took at least 24 h for completion via Sol-Gel method. MW-NiPO-2 and SG-NiPO-2 possess similar structure and composition while MW-NiPO-2 exhibites a worm-like appearance other than piled nanotubes. In com- parison with the sample synthesized via Sol-Gel method, MW-NiPO-2 possesses a relatively high BET surface area (334.4 m 2 /g) and pore volume (0.318 cm 3 /g).