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
A novel bird nest-like nanostructured MnO2(BNNS-MnO2) was prepared by a facile and cost-effective strategy. Their structures and morphologies were characterized by field emission scanning electron microscopy, transmis...A novel bird nest-like nanostructured MnO2(BNNS-MnO2) was prepared by a facile and cost-effective strategy. Their structures and morphologies were characterized by field emission scanning electron microscopy, transmission electron microscopy and powder X-ray diffraction. Capacitive behaviors were investigated by cyclic voltammetry and galvanostatic charge-discharge. The obtained nano-MnO2 possesses a well designed loose-assembled hierarchical nanoarchitecture with an appropriate crystallinity which gives rise to excellent performances as an electrode material for supercapacitors. A maximum specific capacitance of 917 F/g has been obtained at a current density of 5 mA/cm2 in 6 mol/L KOH aqueous solution, and a specific capacitance of 210 F/g has been maintained for 500 cycles. As the low cost of MnSO4 and KCr2O7 and the low reaction temperature, the present method avoids the requirements for complicated operations, time/energy-consuming and expensive reagents, and perhaps is ready for the industrialization of nano-MnO2 production.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supported by the National Natural Science Foundation of China (51203071,51363014 and 21163010)the Key Project of Chinese Ministry of Education (212183)+1 种基金the Program for Hongliu Young Teachers in Lanzhou University of Technology (201201)the Natural Science Funds for Distinguished Young Scholars of Gansu Province (1111RJDA012)
文摘A novel bird nest-like nanostructured MnO2(BNNS-MnO2) was prepared by a facile and cost-effective strategy. Their structures and morphologies were characterized by field emission scanning electron microscopy, transmission electron microscopy and powder X-ray diffraction. Capacitive behaviors were investigated by cyclic voltammetry and galvanostatic charge-discharge. The obtained nano-MnO2 possesses a well designed loose-assembled hierarchical nanoarchitecture with an appropriate crystallinity which gives rise to excellent performances as an electrode material for supercapacitors. A maximum specific capacitance of 917 F/g has been obtained at a current density of 5 mA/cm2 in 6 mol/L KOH aqueous solution, and a specific capacitance of 210 F/g has been maintained for 500 cycles. As the low cost of MnSO4 and KCr2O7 and the low reaction temperature, the present method avoids the requirements for complicated operations, time/energy-consuming and expensive reagents, and perhaps is ready for the industrialization of nano-MnO2 production.
