In this work,the boron phosphide(BP)was synthesized and used for the adsorptive removal of methylene blue(MB)dye from aqueous solutions.To determine the optimum adsorption conditions,studies were performed by varying ...In this work,the boron phosphide(BP)was synthesized and used for the adsorptive removal of methylene blue(MB)dye from aqueous solutions.To determine the optimum adsorption conditions,studies were performed by varying parameters of temperature(298–328 K),pH(2–12),contact time(0–120 min),adsorbent dose(0.01–0.20 g/50 mL),and dye concentration(10–50 mg/L).Different isotherm and kinetic models were applied to the adsorption data.The linear correlations coefficient showed that the Langmuir isotherm best fits(R^(2)=0.9996).The maximum adsorption capacity of BP was obtained as 555.56 mg/g at 55℃and the removal rate reached up to 84.11%.Additionally,the pseudo-second-order kinetic model described the adsorption process best(R^(2)=0.9998).The thermodynamic studies represented that the adsorption occurred spontaneously(ΔG_(A)^(Θ)=−24.90 kJ/mol)and endothermically(ΔH_(A)^(Θ)=16.67 kJ/mol).The results showed that BP is an efficient adsorbent for removing cationic dyes from aqueous solutions.展开更多
Porous carbons are extensively applied in gas separation, water purification, catalytic reaction, and electrochemical processing, attributing to their high specific surface area, large pore volume, chemical inertness,...Porous carbons are extensively applied in gas separation, water purification, catalytic reaction, and electrochemical processing, attributing to their high specific surface area, large pore volume, chemical inertness, and good mechanical and thermal stability. The templating method is widely used to synthesize porous carbons with the controlled pore structure. Among them, preparation of diatomite-templated carbons attracts increasing attention because the obtained carbon has unique developed macropores and exhibits the promising application in adsorption and support of large-sized molecules. Macroporous diatomite-templated carbons are prepared by using additive or inherent solid acid sites of diatomite as the catalyst. The obtained carbons showed tubular and pillared macroporous structures, and had a few mesopores and micropores. However, the carbons possessed the small specific surface area and micropore volume, and thus showed the low adsorption capacity of small-sized molecules, such as methylene blue (MB). In this case, enhancement of porosity, especially microporosity, is necessary.展开更多
Microwave induced catalytic oxidation has been an important mean for treating high-concentration organic pollutants. Microwave catalyst is the key factor of the pollutants removal efficiency. Manganese oxides are exce...Microwave induced catalytic oxidation has been an important mean for treating high-concentration organic pollutants. Microwave catalyst is the key factor of the pollutants removal efficiency. Manganese oxides are excellent microwave absorbing materials which may play a potential role in treating organic pollutants by microwave induction. Manganese oxides are mainly constituted by [MnO6] octohedra connected to form framework or layered structures, and are usually classified into pyrolusite-ramsdellite family with (1×n) tunnel structure, hollandite-romanechite family with (2×n) tunnel structure, todorokite family with (3×n) tunnel structure and birnessite family with (1×∞) layered structure respectively. However, previous studies focused on the catalytic degradation efficiency or process conditions, lack of discussion on the related mechanism and few studies involved in the structural details of the catalysts.展开更多
An attempt was made to prepare carbon coated tourmaline by mixing tourmaline powders and polyvinyl alcohol (PVA), followed by heat treatment in argon atmosphere. All samples were characterized by powder X-ray diffract...An attempt was made to prepare carbon coated tourmaline by mixing tourmaline powders and polyvinyl alcohol (PVA), followed by heat treatment in argon atmosphere. All samples were characterized by powder X-ray diffraction, high-resolution transmission electron microscopy, UV diffuse reflectance spectroscopy. Results showed that the residual carbon content was influenced by heat treatment temperature and the amount of PVA. The degradation of methylene blue by Carbon-coated tourmaline was also studied. The experiments pointed out that the carbon coated effects are best when the heating temperature was 900℃ and the weight content of PVA was 70%. And the tourmaline prepared under 900℃ in the oxidation atmosphere has the best degrade efficiency. The results also proved that the infrared radiation of tourmaline is not effect in the degrade progress.展开更多
In this study,porous silica with high surface area was prepared through selective leaching of thermally activated chlorite in HCl solution.In the process,chlorite was activated by pre-calcining treatment,then activate...In this study,porous silica with high surface area was prepared through selective leaching of thermally activated chlorite in HCl solution.In the process,chlorite was activated by pre-calcining treatment,then activated components(MgO,Al_(2)O_(3),and Fe_(2)O_(3))were selectively leached by acid solution,resulting in the formation of nanopores in situ.The morphology,structure,surface area and pore-size distribution of the material were characterized by XRD,TG/DSC,^(27)Al MAS NMR,SEM,TEM and N2 adsorption−desorption isotherms.The highest specific surface area(SBET=333 m^(2)/g)was obtained by selectively leaching the 600℃ calcined chlorite from 3 mol/L HCl at 90℃ for 2 h.The pore sizes and specific surface areas can be controlled by calcination and leaching conditions.The ^(27)Al MAS NMR spectra of the samples revealed the relationship between structural transformation and the selective acid leaching properties of thermal-activated chlorite,demonstrating that AlVI transfers into AlV when chlorite changes into activated chlorite during thermal activation,and the coordinations of Al has a significant effect on acid solubility of chlorite.The as-prepared porous silica showed favorable adsorption abilities with capacity of 148.79 mg/g for methylene blue at pH of about 7 and temperature of 25℃,indicating its promising potential in adsorption application.展开更多
文摘In this work,the boron phosphide(BP)was synthesized and used for the adsorptive removal of methylene blue(MB)dye from aqueous solutions.To determine the optimum adsorption conditions,studies were performed by varying parameters of temperature(298–328 K),pH(2–12),contact time(0–120 min),adsorbent dose(0.01–0.20 g/50 mL),and dye concentration(10–50 mg/L).Different isotherm and kinetic models were applied to the adsorption data.The linear correlations coefficient showed that the Langmuir isotherm best fits(R^(2)=0.9996).The maximum adsorption capacity of BP was obtained as 555.56 mg/g at 55℃and the removal rate reached up to 84.11%.Additionally,the pseudo-second-order kinetic model described the adsorption process best(R^(2)=0.9998).The thermodynamic studies represented that the adsorption occurred spontaneously(ΔG_(A)^(Θ)=−24.90 kJ/mol)and endothermically(ΔH_(A)^(Θ)=16.67 kJ/mol).The results showed that BP is an efficient adsorbent for removing cationic dyes from aqueous solutions.
文摘Porous carbons are extensively applied in gas separation, water purification, catalytic reaction, and electrochemical processing, attributing to their high specific surface area, large pore volume, chemical inertness, and good mechanical and thermal stability. The templating method is widely used to synthesize porous carbons with the controlled pore structure. Among them, preparation of diatomite-templated carbons attracts increasing attention because the obtained carbon has unique developed macropores and exhibits the promising application in adsorption and support of large-sized molecules. Macroporous diatomite-templated carbons are prepared by using additive or inherent solid acid sites of diatomite as the catalyst. The obtained carbons showed tubular and pillared macroporous structures, and had a few mesopores and micropores. However, the carbons possessed the small specific surface area and micropore volume, and thus showed the low adsorption capacity of small-sized molecules, such as methylene blue (MB). In this case, enhancement of porosity, especially microporosity, is necessary.
文摘Microwave induced catalytic oxidation has been an important mean for treating high-concentration organic pollutants. Microwave catalyst is the key factor of the pollutants removal efficiency. Manganese oxides are excellent microwave absorbing materials which may play a potential role in treating organic pollutants by microwave induction. Manganese oxides are mainly constituted by [MnO6] octohedra connected to form framework or layered structures, and are usually classified into pyrolusite-ramsdellite family with (1×n) tunnel structure, hollandite-romanechite family with (2×n) tunnel structure, todorokite family with (3×n) tunnel structure and birnessite family with (1×∞) layered structure respectively. However, previous studies focused on the catalytic degradation efficiency or process conditions, lack of discussion on the related mechanism and few studies involved in the structural details of the catalysts.
文摘An attempt was made to prepare carbon coated tourmaline by mixing tourmaline powders and polyvinyl alcohol (PVA), followed by heat treatment in argon atmosphere. All samples were characterized by powder X-ray diffraction, high-resolution transmission electron microscopy, UV diffuse reflectance spectroscopy. Results showed that the residual carbon content was influenced by heat treatment temperature and the amount of PVA. The degradation of methylene blue by Carbon-coated tourmaline was also studied. The experiments pointed out that the carbon coated effects are best when the heating temperature was 900℃ and the weight content of PVA was 70%. And the tourmaline prepared under 900℃ in the oxidation atmosphere has the best degrade efficiency. The results also proved that the infrared radiation of tourmaline is not effect in the degrade progress.
基金Project(51772153)supported by the National Natural Science Foundation of China。
文摘In this study,porous silica with high surface area was prepared through selective leaching of thermally activated chlorite in HCl solution.In the process,chlorite was activated by pre-calcining treatment,then activated components(MgO,Al_(2)O_(3),and Fe_(2)O_(3))were selectively leached by acid solution,resulting in the formation of nanopores in situ.The morphology,structure,surface area and pore-size distribution of the material were characterized by XRD,TG/DSC,^(27)Al MAS NMR,SEM,TEM and N2 adsorption−desorption isotherms.The highest specific surface area(SBET=333 m^(2)/g)was obtained by selectively leaching the 600℃ calcined chlorite from 3 mol/L HCl at 90℃ for 2 h.The pore sizes and specific surface areas can be controlled by calcination and leaching conditions.The ^(27)Al MAS NMR spectra of the samples revealed the relationship between structural transformation and the selective acid leaching properties of thermal-activated chlorite,demonstrating that AlVI transfers into AlV when chlorite changes into activated chlorite during thermal activation,and the coordinations of Al has a significant effect on acid solubility of chlorite.The as-prepared porous silica showed favorable adsorption abilities with capacity of 148.79 mg/g for methylene blue at pH of about 7 and temperature of 25℃,indicating its promising potential in adsorption application.
