C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm...C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm.Adsorption and desorption characteristics of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water immersed in alkali solutions and those in C3S-nano SiO2 pastes mixed with alkali solutions,were investigated.Meawhile,the adsorption mechanisms of alkali ions were discussed.Results showed that the contents of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO2 and/or the initial alkali concentrations.In C3S-nano SiO2 pastes mixed with de-ionized water,each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration.No obvious difference between the adsorption capacity of a given paste for K~＋and Na~＋was observed.Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste,and charge compensation of C-S-H gel,mainly by electrostatic interactions.In C3S-nano SiO2 pastes mixed with alkali solutions,alkali ions may enter the structure of C-S-H gel to replace a part of Ca^2＋in the interlayer.This assumption is supported by the structural characterization of C-S-H gel using ^（29）Si MAS NMR.展开更多
For a long time, there has been global concern over the environment and energy problems. Recently, the problems, which have brought about serious effect on the global living condition, have been in the ‘‘spotlight&q...For a long time, there has been global concern over the environment and energy problems. Recently, the problems, which have brought about serious effect on the global living condition, have been in the ‘‘spotlight" and given impetus to the universal's efforts to head for the same direction: stem the worst warming and strive for the renewable energy source. Hydrogen peroxide(H_2O_2) is undoubtedly a good choice,which holds the promise as a clean, efficient, safe and transferrable energy carrier. Octahedral coordination polymer, Cd_3(C_3N_3S_3)_2, was found to be a robust photocatalyst for H_2O_2 generation under visible light irradiation. To further improve the H_2O_2 generation efficiency, adhering the octahedron to reduced graphene(rGO) was applied as the strategy herein. The study shows that by adhering Cd_3(C_3N_3S_3)_2to rGO, the formation of H_2O_2 is 2.5-fold enhanced and its deformation is concurrently suppressed. This work not only demonstrates the effectiveness of adhering Cd_3(C_3N_3S_3)_2polymer to rGO for the improvement of the polymer's photocatalytic performance, but also proposes a general way for the fabrication of graphene/coordination compound hybrids for maximizing their synergy.展开更多
The crystal and molecular structure of the complex containing cobalt-carbon and iron- sulfur cluster cores,(μ-ρ-CH_3C_6H_4C_2S)(μ-n-C_3H_7S)Fe_2(CO)_6Co_2(CO)_6,has been determined by X-ray diffraction method.The c...The crystal and molecular structure of the complex containing cobalt-carbon and iron- sulfur cluster cores,(μ-ρ-CH_3C_6H_4C_2S)(μ-n-C_3H_7S)Fe_2(CO)_6Co_2(CO)_6,has been determined by X-ray diffraction method.The crystals are triclinic,space group P,with a=9.139(2),b=9.610(1), c=17.183(2),α=84.36(1),β=89.45(1),γ=88.15(1)°,V=1501.0~3;Z=2,D_c=1.74 g/cm^3. R=0.072,Rw=0.081.The results of the structure determination show a cobalt-carbon cluster core formed through the reaction of(μ-ρ-CH_3C_6H_4C_2S)(μ-n-C_3H_7S)Fe_2(CO)_6 with Co_2(CO)_8.In the cobalt-carbon cluster core,the bond length of the original C≡C lengthened to 1.324 which is close to the typical value of carbon-carbon double bond.The groups connecting the carbons of the cluster core are in cis position and lie on the opposite side of cobalt atoms.In this complex,the conformation of-SC_3H_7 is e-type,while that of-SC_2C_6H_4CH_3 is a-type.展开更多
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(No.IRT1146)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm.Adsorption and desorption characteristics of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water immersed in alkali solutions and those in C3S-nano SiO2 pastes mixed with alkali solutions,were investigated.Meawhile,the adsorption mechanisms of alkali ions were discussed.Results showed that the contents of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO2 and/or the initial alkali concentrations.In C3S-nano SiO2 pastes mixed with de-ionized water,each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration.No obvious difference between the adsorption capacity of a given paste for K~＋and Na~＋was observed.Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste,and charge compensation of C-S-H gel,mainly by electrostatic interactions.In C3S-nano SiO2 pastes mixed with alkali solutions,alkali ions may enter the structure of C-S-H gel to replace a part of Ca^2＋in the interlayer.This assumption is supported by the structural characterization of C-S-H gel using ^（29）Si MAS NMR.
基金financially supported by the National Natural Science Foundation of China(21003021 and 21373051)
文摘For a long time, there has been global concern over the environment and energy problems. Recently, the problems, which have brought about serious effect on the global living condition, have been in the ‘‘spotlight" and given impetus to the universal's efforts to head for the same direction: stem the worst warming and strive for the renewable energy source. Hydrogen peroxide(H_2O_2) is undoubtedly a good choice,which holds the promise as a clean, efficient, safe and transferrable energy carrier. Octahedral coordination polymer, Cd_3(C_3N_3S_3)_2, was found to be a robust photocatalyst for H_2O_2 generation under visible light irradiation. To further improve the H_2O_2 generation efficiency, adhering the octahedron to reduced graphene(rGO) was applied as the strategy herein. The study shows that by adhering Cd_3(C_3N_3S_3)_2to rGO, the formation of H_2O_2 is 2.5-fold enhanced and its deformation is concurrently suppressed. This work not only demonstrates the effectiveness of adhering Cd_3(C_3N_3S_3)_2polymer to rGO for the improvement of the polymer's photocatalytic performance, but also proposes a general way for the fabrication of graphene/coordination compound hybrids for maximizing their synergy.
文摘The crystal and molecular structure of the complex containing cobalt-carbon and iron- sulfur cluster cores,(μ-ρ-CH_3C_6H_4C_2S)(μ-n-C_3H_7S)Fe_2(CO)_6Co_2(CO)_6,has been determined by X-ray diffraction method.The crystals are triclinic,space group P,with a=9.139(2),b=9.610(1), c=17.183(2),α=84.36(1),β=89.45(1),γ=88.15(1)°,V=1501.0~3;Z=2,D_c=1.74 g/cm^3. R=0.072,Rw=0.081.The results of the structure determination show a cobalt-carbon cluster core formed through the reaction of(μ-ρ-CH_3C_6H_4C_2S)(μ-n-C_3H_7S)Fe_2(CO)_6 with Co_2(CO)_8.In the cobalt-carbon cluster core,the bond length of the original C≡C lengthened to 1.324 which is close to the typical value of carbon-carbon double bond.The groups connecting the carbons of the cluster core are in cis position and lie on the opposite side of cobalt atoms.In this complex,the conformation of-SC_3H_7 is e-type,while that of-SC_2C_6H_4CH_3 is a-type.
