TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals(·CO3–) under solar light irradiation. ·CO3–, a selective radical, was employed to degrade the target tetracyc...TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals(·CO3–) under solar light irradiation. ·CO3–, a selective radical, was employed to degrade the target tetracycline hydrochloride contaminant. A series of characterizations was carried out to study the structure and composition of the synthesized TiO2-seashell composite. This material exhibits excellent solar light-driven photochemical activity in the decomposition of tetracycline hydrochloride. The possible pathway and mechanism for the photodegradation process were proposed on the basis of high-resolution electrospray ionization time-of-flight mass spectrometry experiments. Finally, we investigated the reusability of the TiO2-seashell composite. This study is expected to provide a new facile pathway for the application of ·CO3– radicals to degrade special organic pollutants in water.展开更多
A method of detection hydroxyl radical （ · OH） produced by electrochemical oxidation in organic wastewater treatment was developed. Benzoic acid with weak fluorescence may reacted with hydroxyl radical to produ...A method of detection hydroxyl radical （ · OH） produced by electrochemical oxidation in organic wastewater treatment was developed. Benzoic acid with weak fluorescence may reacted with hydroxyl radical to produce 3-hydroxybenzonic acid with intense fluorescence, whose characteristic fluorescence excitation and e- mission wavelength were at 305 nm and 410 nm. The 3-hydroxybenzonic acid was separated from electroehenaical oxidation system by HPLC. Two major hydroxylated products were quantified corresponding to 3-hydroxybenzonic, 4-hydroxybenzonic acid. Therefore the quantity of hydroxyl radical in the reactive system should be primarily calculated. The optimal experimental program was obtained by studying the determination conditions, which were benzoic acid of 1.0 mmol/L, electrolysis time of 60 min, current density of 39 mA/cm^2 , supporting electrolyte （Na2SO4 ） of 0. 02 mol/L, and the low rate of sparged-air of 25 mL/s. The results show that this method is stable, sinaple and rapid and can be used as a convenient method for the determination of hydroxyl radical.展开更多
Highly efficient,low-cost,and portable wastewater treatment and purification solutions are urgently needed for aqueous pollution removal,especially at remote sites.Synergistic photocatalytic (PC) and persulphate (PS) ...Highly efficient,low-cost,and portable wastewater treatment and purification solutions are urgently needed for aqueous pollution removal,especially at remote sites.Synergistic photocatalytic (PC) and persulphate (PS) degradation under visible light offers an exceptional alternative for this purpose.In this work,we coupled a TiO^(2-)based PC system with a PS oxidation system into a portable advanced oxidation device for rapid and deep degradation of organic contaminants in wastewater.Using hydrogenation,we fabricated hydrogenated anatase branched-rutile TiO_(2) nanorod (H-AB@RTNR) photocatalysts which enable the PC degradation to occur under visible light and improve the utilization of solar energy.We also discovered that the addition of PS resulted in the synergistic degradation of tenacious and persistent organics,dramatically improving the extent and kinetics of the degradation.A degradation rate of 100%and a reaction rate constant of 0.0221 min^(-1)for degrading 1 L rhodamine B(20 mg L^(-1)) were achieved in 120 min in a specially designed thin-layer cell under visible light irradiation.The superior performance of the synergistic PC and PS degradation system was also demonstrated in the degradation of real industrial wastewater.Both remarkable performances can be attributed to the heterophase junction and oxygen vacancies in the photocatalyst that facilitate the catalytic conversion of PS anions into highly active radicals (·SO_(4)-and·OH).This work suggests that the as-proposed synergistic degradation design is a promising solution for building a portable wastewater treatment system.展开更多
文摘TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals(·CO3–) under solar light irradiation. ·CO3–, a selective radical, was employed to degrade the target tetracycline hydrochloride contaminant. A series of characterizations was carried out to study the structure and composition of the synthesized TiO2-seashell composite. This material exhibits excellent solar light-driven photochemical activity in the decomposition of tetracycline hydrochloride. The possible pathway and mechanism for the photodegradation process were proposed on the basis of high-resolution electrospray ionization time-of-flight mass spectrometry experiments. Finally, we investigated the reusability of the TiO2-seashell composite. This study is expected to provide a new facile pathway for the application of ·CO3– radicals to degrade special organic pollutants in water.
基金Sponsored by the Natural Specialism Expense for Base Research (Grant No 2004CB41850)the Scientific Research Foundation of Harbin Institute ofTechnology (Grant No01100677)
文摘A method of detection hydroxyl radical （ · OH） produced by electrochemical oxidation in organic wastewater treatment was developed. Benzoic acid with weak fluorescence may reacted with hydroxyl radical to produce 3-hydroxybenzonic acid with intense fluorescence, whose characteristic fluorescence excitation and e- mission wavelength were at 305 nm and 410 nm. The 3-hydroxybenzonic acid was separated from electroehenaical oxidation system by HPLC. Two major hydroxylated products were quantified corresponding to 3-hydroxybenzonic, 4-hydroxybenzonic acid. Therefore the quantity of hydroxyl radical in the reactive system should be primarily calculated. The optimal experimental program was obtained by studying the determination conditions, which were benzoic acid of 1.0 mmol/L, electrolysis time of 60 min, current density of 39 mA/cm^2 , supporting electrolyte （Na2SO4 ） of 0. 02 mol/L, and the low rate of sparged-air of 25 mL/s. The results show that this method is stable, sinaple and rapid and can be used as a convenient method for the determination of hydroxyl radical.
基金supported by Griffith University PhD scholarshipsthe National Natural Science Foundation of China (22078118)the Natural Science Foundation of Guangdong Province (2019A1515011138)。
文摘Highly efficient,low-cost,and portable wastewater treatment and purification solutions are urgently needed for aqueous pollution removal,especially at remote sites.Synergistic photocatalytic (PC) and persulphate (PS) degradation under visible light offers an exceptional alternative for this purpose.In this work,we coupled a TiO^(2-)based PC system with a PS oxidation system into a portable advanced oxidation device for rapid and deep degradation of organic contaminants in wastewater.Using hydrogenation,we fabricated hydrogenated anatase branched-rutile TiO_(2) nanorod (H-AB@RTNR) photocatalysts which enable the PC degradation to occur under visible light and improve the utilization of solar energy.We also discovered that the addition of PS resulted in the synergistic degradation of tenacious and persistent organics,dramatically improving the extent and kinetics of the degradation.A degradation rate of 100%and a reaction rate constant of 0.0221 min^(-1)for degrading 1 L rhodamine B(20 mg L^(-1)) were achieved in 120 min in a specially designed thin-layer cell under visible light irradiation.The superior performance of the synergistic PC and PS degradation system was also demonstrated in the degradation of real industrial wastewater.Both remarkable performances can be attributed to the heterophase junction and oxygen vacancies in the photocatalyst that facilitate the catalytic conversion of PS anions into highly active radicals (·SO_(4)-and·OH).This work suggests that the as-proposed synergistic degradation design is a promising solution for building a portable wastewater treatment system.
