As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel ox...As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel oxidizing agent for materials chemistry,especially for the oxidation of carbon materials.However,the reported reactivity in liquid phase(H2SO4 medium)is confusing,which ranges from aggressive to moderate,and even incompetent.Meanwhile,the solid-state reactivity underlying the“dry”chemistry of ferrate(VI)remains poorly understood.Herein,we scrutinize the reactivity of K2FeO4 using fullerene C60 and various nanocarbons as substrates.The results unravel a modest reactivity in liquid phase that only oxidizes the active defects on carbon surface and a powerful oxidizing ability in solid state that can open the inert C=C bonds in carbon lattice.We also discuss respective benefit and limitation of the wet and dry approaches.Our work provides a rational understanding on the oxidizing ability of ferrate(VI)and can guide its application in functionalization/transformation of carbons and also other kinds of materials.展开更多
Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine （SMZ） and sulfadiazine （SDZ） are two widely used s...Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine （SMZ） and sulfadiazine （SDZ） are two widely used sulfonamide antibiotics that are used heavily in agriculture. In this study, they were degraded in an aqueous system by chlorination after pre-oxidation with ferrate（VI） （FeVIO2-, Fe（VI））, an environmentally friendly oxidation technique that has been shown to be effective in degrading various organics. The kinetics of the degradation were determined as a function of Fe（VI） （0-1.5 mg/L）, free chlorine （0-1.8 mg/L） and temperature （15- 35℃）. According to the experimental results, SMZ chlorination followed second-order kinetics with increasing Fe（VI） dosage, and the effect of the initial free chlorine concentration on the reaction kinetics with pre-oxidation by Fe（VI） fitted a pseudo-first order model. The rate constants of SDZ and SMZ chlorination at different temperatures were related to the Arrhenius equation. Fe（VI） could reduce the levels of THMs formed and the toxicity of the sulfonamide degradation systems with Fe（VI） doses of 0.5-1.5 mg/L, which provides a reference for ensuring water quality in drinking water systems.展开更多
基金financial support from National Key Research and Development Program of China (2017YFA0207500)National Natural Science Foundation of China (51673114,51973111)Shanghai Science and Technology Committee (17ZR1447300)
文摘As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel oxidizing agent for materials chemistry,especially for the oxidation of carbon materials.However,the reported reactivity in liquid phase(H2SO4 medium)is confusing,which ranges from aggressive to moderate,and even incompetent.Meanwhile,the solid-state reactivity underlying the“dry”chemistry of ferrate(VI)remains poorly understood.Herein,we scrutinize the reactivity of K2FeO4 using fullerene C60 and various nanocarbons as substrates.The results unravel a modest reactivity in liquid phase that only oxidizes the active defects on carbon surface and a powerful oxidizing ability in solid state that can open the inert C=C bonds in carbon lattice.We also discuss respective benefit and limitation of the wet and dry approaches.Our work provides a rational understanding on the oxidizing ability of ferrate(VI)and can guide its application in functionalization/transformation of carbons and also other kinds of materials.
基金supported by the National Natural Science Foundation of China(Nos.51778565,51578487)the Zhejiang Provincial Natural Science Foundation of China(No.LY15E080005)
文摘Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine （SMZ） and sulfadiazine （SDZ） are two widely used sulfonamide antibiotics that are used heavily in agriculture. In this study, they were degraded in an aqueous system by chlorination after pre-oxidation with ferrate（VI） （FeVIO2-, Fe（VI））, an environmentally friendly oxidation technique that has been shown to be effective in degrading various organics. The kinetics of the degradation were determined as a function of Fe（VI） （0-1.5 mg/L）, free chlorine （0-1.8 mg/L） and temperature （15- 35℃）. According to the experimental results, SMZ chlorination followed second-order kinetics with increasing Fe（VI） dosage, and the effect of the initial free chlorine concentration on the reaction kinetics with pre-oxidation by Fe（VI） fitted a pseudo-first order model. The rate constants of SDZ and SMZ chlorination at different temperatures were related to the Arrhenius equation. Fe（VI） could reduce the levels of THMs formed and the toxicity of the sulfonamide degradation systems with Fe（VI） doses of 0.5-1.5 mg/L, which provides a reference for ensuring water quality in drinking water systems.
