The morphology of supported metal nanoparticles on TiO2/silical gel （TSO） and photothermal synergism were investigated for destruction of ethylene. During photocatalytic deposition of metal nanopartilces, the effect...The morphology of supported metal nanoparticles on TiO2/silical gel （TSO） and photothermal synergism were investigated for destruction of ethylene. During photocatalytic deposition of metal nanopartilces, the effects of pH and light intensity on the morphology of coated platinum, palladium, gold on TiO2/silical gel were studied. Moreover, these catalysts were characterized by TEM, UV-Vis DRS. The pH of preparing solution have strong influence on dispersion, size and sites of Pt, Pd and Au on TSO, which were controlled by the electrostatic binding of HPtCl5^- AuCl4^- and TiOH2^＋, Pd^2＋ and TiO^- respectively. Platinum, gold and palladium nanoparticles were uniformly highly dispersed on the titanol sites not silanol of TiO2/silical gel under pH=2, pH =9.9 respectively. For the photodegradation of ethylene, they show higher photothermal efficiency than those prepared with other pH conditions under UV illumination in a non-circulating photoreactor. The optimum weight loadings of Pt, Au, and Pd were 0.25 wt%, 0.5 wt%, 1 wt%, respectively. The synergistic effect enhanced ethylene removal and CO2 production. Thcse results verify that the best photothermal synergistic effect depends on the dispersion, size of noble metal nano-particles. FTIR analyses of the used Pt-, Pd-TSO catalysts indicated that no significant by-products were accumulated on the surface of the catalysts, leading to them longer lifetime.展开更多
Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation.Sodium silicate is commonly used to depress calcium-bearing gangue minerals,however it can also depress bastnaesite when Ca^(2+) ...Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation.Sodium silicate is commonly used to depress calcium-bearing gangue minerals,however it can also depress bastnaesite when Ca^(2+) ions exist in the pulp.In this study,the effect of Ca^(2+) ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation,zeta potential,fluorescence spectroscopy and X-ray photoelectron spectroscopy(XPS) measurements.Micro-flotation results show that the combination of Ca^(2+) ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect.Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly.Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely.XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO_(3) precipitate,which causes more serious depression on bastnaesite flotation.展开更多
Silicon （Si） incorporated porous TiO2 coating （Si-TiO2） prepared on titanium （Ti） by micro-arc oxidation （MAO） technique was demonstrated to be cytocompatible in previous studies. In view of the potential clin...Silicon （Si） incorporated porous TiO2 coating （Si-TiO2） prepared on titanium （Ti） by micro-arc oxidation （MAO） technique was demonstrated to be cytocompatible in previous studies. In view of the potential clinical applications, a detailed in vitro study of the biological activity of Si-Ti02 coating, in terms of osteoblast （MC3T3-EI cells） morphology, proliferation, differentiation and mineralization was performed. Immunofluo- rescent staining indicated that cells seeded on the Si-TiO2 coating showed improved adhesion with developing mature cytoskeletons, which contained numerous distinct and well-defined actin stress fibers in the cell mem- branes compared with those on the Ti02 coating and Ti plate. Results from proliferation assay showed that the proliferation rate of cells seeded on the Si-TiO2coating was significantly faster than that on the TiO2 coating and Ti plate. Furthermore, the analysis of osteogenic gene expression demonstrated that the Si-Ti02 coating stimulated the expression of osteoblast-related genes and promoted differentiation and mineralization of MC3T3-EI cells. In addition, the Si-TiO2 coating differentially regulated Wnt signaling pathway by up-regulating the expression of low-density lipoprotein （LDL） receptor-related protein 5 （LrpS）, and downregulating the expression of Dickkopf-1 （Dkkl）. All together, these results indicate that the investigated titanium with Si-TiO2 coating is biocompatible and a good candidate material used as implants.展开更多
By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, F...By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, FTIR, UVvis,SEM, EDS, and TEM techniques. The test results showed that TiO_2 was amorphous, the TiO_2/BMMS catalyst had an ordered bimodal mesoporous structure, and the chemical interaction existed between BMMS and TiO_2. Since the TiO_2/BMMS had a lower band gap, its photocatalytic activity was better than TiO_2. Under UV irradiation a one-pot PODS system was set up, using TiO_2/BMMS as the catalyst, H_2O_2 as the oxidant, and methanol as the solvent. The TiO_2/BMMS catalyst showed better photocatalytic activity than the mono-modal mesoporous TiO_2/SBA-15 catalyst, and the desulfurization rate of dibenzothiophene(DBT) over TiO_2/BMMS catalyst could reach 99._2%. The TiO_2/BMMS catalyst also had so good stability that the desulfurization rate of DBT did not drop apparently after 8 cycles of reusing, and could still be close to 90%.展开更多
The phase transition,morphology,stability and pulverization performance of dicalcium silicate(C_(2)S)with different Na_(2)O additions during the high-temperature sintering process were studied using XRD,SEM-EDS,FT-IR,...The phase transition,morphology,stability and pulverization performance of dicalcium silicate(C_(2)S)with different Na_(2)O additions during the high-temperature sintering process were studied using XRD,SEM-EDS,FT-IR,and Raman spectra methods.When the CaO to SiO_(2) molar ratio is 2.0 and the Na_(2)O to SiO_(2) molar ratio is below 0.20,the crystalline calcium silicate compounds includeγ-C_(2)S andβ-C_(2)S.As the Na_(2)O addition increases,the proportion,crystallinity and grain size ofβ-C_(2)S in the sintered products increase,those parameters ofγ-C_(2)S decrease,and the content of amorphous phase increases.Na_(2)O mainly forms solid solutions inβ-C_(2)S and inhibits the transition ofβ-C_(2)S toγ-C_(2)S,resulting in the sintered products unpulverized.The stability of sintered products in alkali solution decreases significantly with the increasing Na_(2)O additions,and theβ-C_(2)S solid solution with Na_(2)O is less stable thanγ-C_(2)S.The mechanism that Na_(2)O affects the transition of C_(2)S as well as its stability was also discussed,which can give actual guidance for the treatment of low-grade alumina-containing resources by the sintering process.展开更多
TiO2 thin film has attracted considerable attention in recent years, due to its different refractive index and transparency with amorphous and different crysta ls in the visible and near-infrared wavelength region, hi...TiO2 thin film has attracted considerable attention in recent years, due to its different refractive index and transparency with amorphous and different crysta ls in the visible and near-infrared wavelength region, high dielectric constant, wide band gap, high wear resistance and stability, etc, for which make it being used in many fields. This paper aims to investigate the optical characterizatio n of thin film TiO2 on silicon wafer. The TiO2 thin films were prepared by DC re active magnetron sputtering process from Ti target. The reflectivity of the film s was measured by UV-3101PC, and the index of refraction (n) and extinction coef ficient (k) were measured by n & k Analyzer 1200.展开更多
Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhi...Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.展开更多
Ag loaded mesoporous silica-embedded TiO_2 nanocomposites were successfully synthesized via two different routes,including one-pot solvothermal method and solvothermal-chemical reduction method,both using Titanium（Ⅳ...Ag loaded mesoporous silica-embedded TiO_2 nanocomposites were successfully synthesized via two different routes,including one-pot solvothermal method and solvothermal-chemical reduction method,both using Titanium（Ⅳ） n-butoxide（Ti（OC_4H_9）_4） as a precursor,formic acid as a solvent and reducing agent,silver nitrate as a silver source and tetraethyl silicate（TEOS） as a stabilizer.The transmission electron microscopic（TEM） images showed that silica-embedded anatase TiO_2 sample exhibited approximately rhombic shape and Ag nanoparticles could be embedded into the nanocomposites or deposited on the surface with high dispersion.The N_2 adsorption-desorption isotherms indicated that the silica-embedded anatase TiO_2 had obvious mesoporous structure with a BET specific surface area of 203.5 m^2·g^-1.All Ag loaded silica-embedded TiO_2composites showed a higher photocatalytic H2-generation activity from water splitting under simulative solar light irradiation than that of TiO2 products.The maximum H_2 production rate（6.10 mmol·h^-1·g^-1） was obtained over 2%Ag/silica-embedded TiO2 nanocomposites（2%Ag/MST） prepared by solvothermal-chemical reduction method,which was 20 times that achieved on the silica-embedded TiO2 sample.The enhanced photocatalytic H2-evolution activity of Ag loaded mesoporous silica-embedded TiO2 nanocomposites can be attributed to the multi-function of surface Ag co-catalyst,mesoporous structure,and embedding of silica.展开更多
CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as...CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as a construction base,with considerable application prospects.Nevertheless,the components responsible for CO_(2)sequestration in steel slag predominantly exist as silicates,whose chemical inertness leads to suboptimal CO_(2)sequestration efficiency in the slag.Based on the strategy of activating the silicate components in steel slag with the alkali metal potassium(K)to improve the CO_(2)sequestration performance of steel slag,both experiments and theoretical calculations were performed to give a deep insight into the effect and mechanism of K modification on enhancing the CO_(2)sequestration capability of steel slag.In experiments,CO_(2)sequestration capacity of steel slag modified with 3 wt.%K reached 100.15 g/kg at 1000 K.Theoretical analysis has revealed that although K exhibits low reactivity,it enhances the electronic transition and amplifies charge localization at specific sites within Ca_(2)SiO_(4),consequently improving its CO_(2)sequestration capacity.However,an excessive doping of K led to the partial inactivation of some active sites within Ca_(2)SiO_(4).Furthermore,CO_(2)chemisorption on Ca_(2)SiO_(4)surface predominantly occurs through the chelate configuration of CO_(3)^(2−),suggesting the formation of a CaCO_(3)precursor.Thus,both the experimental results and theoretical calculations reveal the role of K on enhancing CO_(2)sequestration capability of steel slag.In summary,K modification offers promising prospects for improving CO_(2)sequestration properties of steel slag and provides support for the industrial implementation of carbon sequestration by steel slag.展开更多
Recoverable TiO2 photocatalysis material supported by silicon powder was prepared with sol-gel method, afterwards the silica gol and sodium silicate were used as molding binder respectively to investigate their effec...Recoverable TiO2 photocatalysis material supported by silicon powder was prepared with sol-gel method, afterwards the silica gol and sodium silicate were used as molding binder respectively to investigate their effects （including binder type and binder addition quantity） on the crystal structure and catalysis properties of photocatalyst. In this work, the catalysis activity was defined as the degradation rate of methyl orange solution upon ultraviolet lamp irradiation, and the specific areas were determined with nitrogen desorption method. TiO2 crystal form was measured with X-ray powder diffraction and their micro-morphology was observed with SEM. Experimental results indicate that these two binders do not affect the crystal form transformation of TiO2, but silica gol can increase the specific surface area of TiO2 photocatalyst obviously and the addition of sodium silicate can decrease it. In all, silica gol is a better candidate than sodium silicate for higher catalysis property. In conclusion, 6% silica gol is the optimal addition concentration. Under this condition, the ratio of anatase to rutile TiO2 is 64：36, the specific area is 29.67 m^2/g, and as expected, the degradation rate of methyl orange could be as high as 90% after irradiation for 5 days.展开更多
文摘The morphology of supported metal nanoparticles on TiO2/silical gel （TSO） and photothermal synergism were investigated for destruction of ethylene. During photocatalytic deposition of metal nanopartilces, the effects of pH and light intensity on the morphology of coated platinum, palladium, gold on TiO2/silical gel were studied. Moreover, these catalysts were characterized by TEM, UV-Vis DRS. The pH of preparing solution have strong influence on dispersion, size and sites of Pt, Pd and Au on TSO, which were controlled by the electrostatic binding of HPtCl5^- AuCl4^- and TiOH2^＋, Pd^2＋ and TiO^- respectively. Platinum, gold and palladium nanoparticles were uniformly highly dispersed on the titanol sites not silanol of TiO2/silical gel under pH=2, pH =9.9 respectively. For the photodegradation of ethylene, they show higher photothermal efficiency than those prepared with other pH conditions under UV illumination in a non-circulating photoreactor. The optimum weight loadings of Pt, Au, and Pd were 0.25 wt%, 0.5 wt%, 1 wt%, respectively. The synergistic effect enhanced ethylene removal and CO2 production. Thcse results verify that the best photothermal synergistic effect depends on the dispersion, size of noble metal nano-particles. FTIR analyses of the used Pt-, Pd-TSO catalysts indicated that no significant by-products were accumulated on the surface of the catalysts, leading to them longer lifetime.
基金Project supported by the National Natural Science Foundation of China(51764045)the Open Project of State Key Laboratory of Mineral Processing(BGRIMM-KJSKL-2020-23)+2 种基金the Excellent Youth Foundation of IMUST(2017YQL05)the Inner Mongolia Natural Science Foundation(2020LH05027,2019MS05039)the Inner Mongolia Major Basic Research Open Project(0406091701)。
文摘Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation.Sodium silicate is commonly used to depress calcium-bearing gangue minerals,however it can also depress bastnaesite when Ca^(2+) ions exist in the pulp.In this study,the effect of Ca^(2+) ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation,zeta potential,fluorescence spectroscopy and X-ray photoelectron spectroscopy(XPS) measurements.Micro-flotation results show that the combination of Ca^(2+) ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect.Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly.Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely.XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO_(3) precipitate,which causes more serious depression on bastnaesite flotation.
基金supported by Shanghai Science and Technology R&D Fund(Grant No.0952nm04400)the National Natural Science Foundation of China(GrantNos.51071168and30973041)the Innovation Fund of SIC,CAS(Grant No.Y06ZC3130G)
文摘Silicon （Si） incorporated porous TiO2 coating （Si-TiO2） prepared on titanium （Ti） by micro-arc oxidation （MAO） technique was demonstrated to be cytocompatible in previous studies. In view of the potential clinical applications, a detailed in vitro study of the biological activity of Si-Ti02 coating, in terms of osteoblast （MC3T3-EI cells） morphology, proliferation, differentiation and mineralization was performed. Immunofluo- rescent staining indicated that cells seeded on the Si-TiO2 coating showed improved adhesion with developing mature cytoskeletons, which contained numerous distinct and well-defined actin stress fibers in the cell mem- branes compared with those on the Ti02 coating and Ti plate. Results from proliferation assay showed that the proliferation rate of cells seeded on the Si-TiO2coating was significantly faster than that on the TiO2 coating and Ti plate. Furthermore, the analysis of osteogenic gene expression demonstrated that the Si-Ti02 coating stimulated the expression of osteoblast-related genes and promoted differentiation and mineralization of MC3T3-EI cells. In addition, the Si-TiO2 coating differentially regulated Wnt signaling pathway by up-regulating the expression of low-density lipoprotein （LDL） receptor-related protein 5 （LrpS）, and downregulating the expression of Dickkopf-1 （Dkkl）. All together, these results indicate that the investigated titanium with Si-TiO2 coating is biocompatible and a good candidate material used as implants.
基金financially supported by the Program for Liaoning Excellent Talents in University,abbreviated as“LNET”(LJQ2015062)Program for Science and Technology Agency of Liaoning Province(20170540585)+1 种基金General Scientific Research Project of Liaoning Provincial Department of Education(L2015296,L2016018)Science and Technology Planning project of Fushun(FSKJHT201376)
文摘By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, FTIR, UVvis,SEM, EDS, and TEM techniques. The test results showed that TiO_2 was amorphous, the TiO_2/BMMS catalyst had an ordered bimodal mesoporous structure, and the chemical interaction existed between BMMS and TiO_2. Since the TiO_2/BMMS had a lower band gap, its photocatalytic activity was better than TiO_2. Under UV irradiation a one-pot PODS system was set up, using TiO_2/BMMS as the catalyst, H_2O_2 as the oxidant, and methanol as the solvent. The TiO_2/BMMS catalyst showed better photocatalytic activity than the mono-modal mesoporous TiO_2/SBA-15 catalyst, and the desulfurization rate of dibenzothiophene(DBT) over TiO_2/BMMS catalyst could reach 99._2%. The TiO_2/BMMS catalyst also had so good stability that the desulfurization rate of DBT did not drop apparently after 8 cycles of reusing, and could still be close to 90%.
基金Project(2018YFC1901903)supported by the National Key R&D Program of ChinaProjects(22078055,52074083,51674075)supported by the National Natural Science Foundation of China。
文摘The phase transition,morphology,stability and pulverization performance of dicalcium silicate(C_(2)S)with different Na_(2)O additions during the high-temperature sintering process were studied using XRD,SEM-EDS,FT-IR,and Raman spectra methods.When the CaO to SiO_(2) molar ratio is 2.0 and the Na_(2)O to SiO_(2) molar ratio is below 0.20,the crystalline calcium silicate compounds includeγ-C_(2)S andβ-C_(2)S.As the Na_(2)O addition increases,the proportion,crystallinity and grain size ofβ-C_(2)S in the sintered products increase,those parameters ofγ-C_(2)S decrease,and the content of amorphous phase increases.Na_(2)O mainly forms solid solutions inβ-C_(2)S and inhibits the transition ofβ-C_(2)S toγ-C_(2)S,resulting in the sintered products unpulverized.The stability of sintered products in alkali solution decreases significantly with the increasing Na_(2)O additions,and theβ-C_(2)S solid solution with Na_(2)O is less stable thanγ-C_(2)S.The mechanism that Na_(2)O affects the transition of C_(2)S as well as its stability was also discussed,which can give actual guidance for the treatment of low-grade alumina-containing resources by the sintering process.
基金This work was supported by the National Natural Science Foundation of China(No,50376067)the Plan for Science&Technology Development of Guangzhou(2001-Z-117-01).
文摘TiO2 thin film has attracted considerable attention in recent years, due to its different refractive index and transparency with amorphous and different crysta ls in the visible and near-infrared wavelength region, high dielectric constant, wide band gap, high wear resistance and stability, etc, for which make it being used in many fields. This paper aims to investigate the optical characterizatio n of thin film TiO2 on silicon wafer. The TiO2 thin films were prepared by DC re active magnetron sputtering process from Ti target. The reflectivity of the film s was measured by UV-3101PC, and the index of refraction (n) and extinction coef ficient (k) were measured by n & k Analyzer 1200.
基金the financial support from the National Key Research and Development Program of China(No.2018YFC1903403)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.
基金Funded by Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions
文摘Ag loaded mesoporous silica-embedded TiO_2 nanocomposites were successfully synthesized via two different routes,including one-pot solvothermal method and solvothermal-chemical reduction method,both using Titanium（Ⅳ） n-butoxide（Ti（OC_4H_9）_4） as a precursor,formic acid as a solvent and reducing agent,silver nitrate as a silver source and tetraethyl silicate（TEOS） as a stabilizer.The transmission electron microscopic（TEM） images showed that silica-embedded anatase TiO_2 sample exhibited approximately rhombic shape and Ag nanoparticles could be embedded into the nanocomposites or deposited on the surface with high dispersion.The N_2 adsorption-desorption isotherms indicated that the silica-embedded anatase TiO_2 had obvious mesoporous structure with a BET specific surface area of 203.5 m^2·g^-1.All Ag loaded silica-embedded TiO_2composites showed a higher photocatalytic H2-generation activity from water splitting under simulative solar light irradiation than that of TiO2 products.The maximum H_2 production rate（6.10 mmol·h^-1·g^-1） was obtained over 2%Ag/silica-embedded TiO2 nanocomposites（2%Ag/MST） prepared by solvothermal-chemical reduction method,which was 20 times that achieved on the silica-embedded TiO2 sample.The enhanced photocatalytic H2-evolution activity of Ag loaded mesoporous silica-embedded TiO2 nanocomposites can be attributed to the multi-function of surface Ag co-catalyst,mesoporous structure,and embedding of silica.
基金supported by China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202202)Major Industry Innovation Plan of Anhui Province(AHZDCYCX-LSDT2023-01).
文摘CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as a construction base,with considerable application prospects.Nevertheless,the components responsible for CO_(2)sequestration in steel slag predominantly exist as silicates,whose chemical inertness leads to suboptimal CO_(2)sequestration efficiency in the slag.Based on the strategy of activating the silicate components in steel slag with the alkali metal potassium(K)to improve the CO_(2)sequestration performance of steel slag,both experiments and theoretical calculations were performed to give a deep insight into the effect and mechanism of K modification on enhancing the CO_(2)sequestration capability of steel slag.In experiments,CO_(2)sequestration capacity of steel slag modified with 3 wt.%K reached 100.15 g/kg at 1000 K.Theoretical analysis has revealed that although K exhibits low reactivity,it enhances the electronic transition and amplifies charge localization at specific sites within Ca_(2)SiO_(4),consequently improving its CO_(2)sequestration capacity.However,an excessive doping of K led to the partial inactivation of some active sites within Ca_(2)SiO_(4).Furthermore,CO_(2)chemisorption on Ca_(2)SiO_(4)surface predominantly occurs through the chelate configuration of CO_(3)^(2−),suggesting the formation of a CaCO_(3)precursor.Thus,both the experimental results and theoretical calculations reveal the role of K on enhancing CO_(2)sequestration capability of steel slag.In summary,K modification offers promising prospects for improving CO_(2)sequestration properties of steel slag and provides support for the industrial implementation of carbon sequestration by steel slag.
基金the Natural Science Foundation of Fujian Province(No.T08J0129)the Science and Technology Developing Foundation of Fuzhou University(No. 2008-XQ-001)Research Project of the Education Department of Fujian Province(JA05185)
文摘Recoverable TiO2 photocatalysis material supported by silicon powder was prepared with sol-gel method, afterwards the silica gol and sodium silicate were used as molding binder respectively to investigate their effects （including binder type and binder addition quantity） on the crystal structure and catalysis properties of photocatalyst. In this work, the catalysis activity was defined as the degradation rate of methyl orange solution upon ultraviolet lamp irradiation, and the specific areas were determined with nitrogen desorption method. TiO2 crystal form was measured with X-ray powder diffraction and their micro-morphology was observed with SEM. Experimental results indicate that these two binders do not affect the crystal form transformation of TiO2, but silica gol can increase the specific surface area of TiO2 photocatalyst obviously and the addition of sodium silicate can decrease it. In all, silica gol is a better candidate than sodium silicate for higher catalysis property. In conclusion, 6% silica gol is the optimal addition concentration. Under this condition, the ratio of anatase to rutile TiO2 is 64：36, the specific area is 29.67 m^2/g, and as expected, the degradation rate of methyl orange could be as high as 90% after irradiation for 5 days.
