Preparation And Application Of Phosphorus-sulfur-modified Boehmite With Large Pore And High Surface Area

Alumina,as a cheap and easily available inorganic material,is widely used in industrial production processes such as chemical industry and environmental protection because of its high specific surface area and large pore volume.Boehmite is an important precursor of alumina,and its surface properties,such as specific surface area,pore volume,etc,directly affect the surface properties of alumina.Although the laboratory can prepare boehmite with large pores and high specific surface area through methods such as supercritical drying,it is difficult to industrially produce because the raw materials are expensive and the preparation process is complicated.Using a simple and low-cost method to prepare boehmite with both large pores and high large specific surface area is a major challenge facing researchers.In recent years,some researchers have explored the influence of inorganic anions on the synthesis of boehmite,but they are limited to rough exploration,and there are no detailed reports so far.In this paper,aluminum chloride hexahydrate and sodium metaaluminate were used as acid and base aluminum sources,and simple hydrothermal synthesis method was used.Disodium hydrogen phosphate and sodium sulfate were added in the synthesis process.The amount of phosphorus and sulfur doped,the influence of different amounts of phosphorus and sulfur in different order on the synthesis of boehmite were explored.It was found that the doping of sulfur and phosphorus had a guiding effect on the boehmite crystal planes,which would limit the growth of b-axis,thus forming a thinner two-dimensional lamellar structure.Without adding any template and organic solvent,boehmite with the specific surface area 863.Om2/g and the pore volume 4.10cm3/g prepared.The boehmite with "House of Cards" structure had a large pore and high specific surface area.The above-mentioned boehmite with large pore and high specific surface area was calcined at high temperature,the γ-alumina was obtained.Its specific surface area was 644.3 m2/g and pore volume was 4.08 cm3/g.The adsorption experiment of basic fuchsin in water was carried out.Treating 200 mg/g dye wastewater,when the adsorption equilibrium was reached,the adsorption capacity was 100.30 mg/g.After 20 min,the adsorption capacity reached 85.4%of the equilibrium adsorption capacity.The adsorption of basic fuchsin by modified alumina conformed to the pseudo-second-order kinetics.Adsorption was a single-layer adsorption,in line with the Langmuir isotherm adsorption model.