Microbial fuel cells(MFCs)benefit from the introduction of iron in the anode,as its multiple valence states and high electron-catalytic activity led to improved power densities in MFCs.However,the effect of long-term ...Microbial fuel cells(MFCs)benefit from the introduction of iron in the anode,as its multiple valence states and high electron-catalytic activity led to improved power densities in MFCs.However,the effect of long-term Fe 3+release into the electrolyte on the power density of MFCs is often overlooked.Herein,an anode consisting of a three-dimensional iron foam uniformly coated by reduced graphene oxide(rGO/IF)with a suitable loading density(8g/m^(2))and a large specific surface area(0.05m^(2)/g)for high-density bacterial loading was prepared.The hybrid cells based on the rGO/IF anode exhibit a maximum power density of 5330±76mW/m 2 contributed by MFCs and galvanic cells.The rGO/IF anode enables continuous Fe 3+release for high electron-catalytic activity in the electrolyte during the discharging of the galvanic cells.As a result,the hybrid cells showed a power density of 2107±64mW/m^(2)after four cycles,facilitated through reversible conversion between Fe^(3+)and Fe^(2+)in the electrolyte to accelerate electron transfer efficiency.The results indicate that the rGO/IF anode can be used for designing and fabricating high-power MFCs by optimizing the rate of release of Fe^(3+)in the electrolyte.展开更多
Low-temperature energy harvest,delivery,and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control.Herein,we pr...Low-temperature energy harvest,delivery,and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control.Herein,we propose a light-driven photo-energy delivery device with a series of photo-responsive alkoxy-grafted azobenzene-based phase-change materials(a-g-Azo PCMs).These a-g-Azo PCMs store and release crystallization and isomerization enthalpies,reaching a high energy density of 380.76 J/g even at a low temperature of-63.92℃.On this basis,we fabricate a novel three-branch light-driven microfluidic control device for distributed energy recycling that achieves light absorption,energy storage,controlled movement,and selective release cyclically over a wide range of temperatures.The a-g-Azo PCMs move remote-controllably in the microfluidic device at an average velocity of 0.11-0.53 cm/s owing to the asymmetric thermal expansion effect controlled by the temperature difference.During movement,the optically triggered heat release of a-g-Azo PCMs achieves a temperature difference of 6.6℃ even at a low temperature of-40℃.These results provide a new technology for energy harvest,delivery,and utilization in low-temperature environments via a remote manipulator.展开更多
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB3805702National Natural Science Foundation of China,Grant/Award Numbers:51973152,52130303Science Fund for Distinguished Young Scholars of Tianjin Municipality,Grant/Award Number:19JCJQJC61700。
文摘Microbial fuel cells(MFCs)benefit from the introduction of iron in the anode,as its multiple valence states and high electron-catalytic activity led to improved power densities in MFCs.However,the effect of long-term Fe 3+release into the electrolyte on the power density of MFCs is often overlooked.Herein,an anode consisting of a three-dimensional iron foam uniformly coated by reduced graphene oxide(rGO/IF)with a suitable loading density(8g/m^(2))and a large specific surface area(0.05m^(2)/g)for high-density bacterial loading was prepared.The hybrid cells based on the rGO/IF anode exhibit a maximum power density of 5330±76mW/m 2 contributed by MFCs and galvanic cells.The rGO/IF anode enables continuous Fe 3+release for high electron-catalytic activity in the electrolyte during the discharging of the galvanic cells.As a result,the hybrid cells showed a power density of 2107±64mW/m^(2)after four cycles,facilitated through reversible conversion between Fe^(3+)and Fe^(2+)in the electrolyte to accelerate electron transfer efficiency.The results indicate that the rGO/IF anode can be used for designing and fabricating high-power MFCs by optimizing the rate of release of Fe^(3+)in the electrolyte.
基金Science Foundation for Distinguished Young Scholars in Tianjin,Grant/Award Number:19JCJQJC61700National Natural Science Foundation of China,Grant/Award Numbers:52327802,52173078,51973152+1 种基金National Key R&D Program of China,Grant/Award Number:2022YFB3805702State Key Program of National Natural Science Foundation of China,Grant/Award Number:52130303。
文摘Low-temperature energy harvest,delivery,and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control.Herein,we propose a light-driven photo-energy delivery device with a series of photo-responsive alkoxy-grafted azobenzene-based phase-change materials(a-g-Azo PCMs).These a-g-Azo PCMs store and release crystallization and isomerization enthalpies,reaching a high energy density of 380.76 J/g even at a low temperature of-63.92℃.On this basis,we fabricate a novel three-branch light-driven microfluidic control device for distributed energy recycling that achieves light absorption,energy storage,controlled movement,and selective release cyclically over a wide range of temperatures.The a-g-Azo PCMs move remote-controllably in the microfluidic device at an average velocity of 0.11-0.53 cm/s owing to the asymmetric thermal expansion effect controlled by the temperature difference.During movement,the optically triggered heat release of a-g-Azo PCMs achieves a temperature difference of 6.6℃ even at a low temperature of-40℃.These results provide a new technology for energy harvest,delivery,and utilization in low-temperature environments via a remote manipulator.
