The immobilization of catalysts on supporting substrates for the removal of organic pollutants is a crucial strategy for mitigating catalyst loss during wastewater treatment.This study presented a rapid and cost-effec...The immobilization of catalysts on supporting substrates for the removal of organic pollutants is a crucial strategy for mitigating catalyst loss during wastewater treatment.This study presented a rapid and cost-effective direct heating method for synthesizing MnO2 nanoflowers on coil substrates for the removal of organic pollutants.Traditional methods often require high power,expensive equipment,and long synthesis times.In contrast,the direct heating approach successfully synthesized MnO2 nanoflowers in just 10 min with a heating power of approximately 40 W·h after the heating power and duration were optimized.These nanoflowers effectively degraded 99%Rhodamine B in 60 min with consistent repeatability.The catalytic mechanisms are attributed to crystal defects in MnO2,which generate electrons to produce H2O2.Mn2+ions in the acidic solution further dissociate H2O2 molecules into hydroxyl radicals(·OH).The high efficiency of this synthesis method and the excellent reusability of MnO2 nanoflowers highlight their potential as a promising solution for the development of supporting MnO2 catalysts for organic dye removal applications.展开更多
In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nan...In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nanosheets into MoS2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect（IFE）.Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO2 nanosheets.Under the optimum conditions,the limit of detection（LOD） of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples（n = 3）.Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.展开更多
基金supported by Ministry of Higher Education,Malaysia,through the Fundamental Research Grant Scheme(FRGS)(Grant No.FRGS/1/2020/TK0/USM/02/27)。
文摘The immobilization of catalysts on supporting substrates for the removal of organic pollutants is a crucial strategy for mitigating catalyst loss during wastewater treatment.This study presented a rapid and cost-effective direct heating method for synthesizing MnO2 nanoflowers on coil substrates for the removal of organic pollutants.Traditional methods often require high power,expensive equipment,and long synthesis times.In contrast,the direct heating approach successfully synthesized MnO2 nanoflowers in just 10 min with a heating power of approximately 40 W·h after the heating power and duration were optimized.These nanoflowers effectively degraded 99%Rhodamine B in 60 min with consistent repeatability.The catalytic mechanisms are attributed to crystal defects in MnO2,which generate electrons to produce H2O2.Mn2+ions in the acidic solution further dissociate H2O2 molecules into hydroxyl radicals(·OH).The high efficiency of this synthesis method and the excellent reusability of MnO2 nanoflowers highlight their potential as a promising solution for the development of supporting MnO2 catalysts for organic dye removal applications.
基金financially supported by National Nature Science Foundation of China (No. 21475053)
文摘In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nanosheets into MoS2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect（IFE）.Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO2 nanosheets.Under the optimum conditions,the limit of detection（LOD） of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples（n = 3）.Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.
