Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low e...Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.展开更多
Binuclear ruthenium complexes bearing the2,2'‐bipyridine‐6,6'‐dicarboxylate(bda)ligand have been demonstrated to be highly active catalysts towards water oxidation with CeIV as an oxidant.However,the cataly...Binuclear ruthenium complexes bearing the2,2'‐bipyridine‐6,6'‐dicarboxylate(bda)ligand have been demonstrated to be highly active catalysts towards water oxidation with CeIV as an oxidant.However,the catalytic properties of ruthenium dimers have not yet been explored for visible light‐driven water oxidation.Herein,the photocatalytic performance of a dipyridyl propane‐bridged ruthenium dimer2was investigated in comparison with its monomeric precursor,[Ru(bda)(pic)2](1),in CH3CN/phosphate buffer mixed solvent in a three‐component system including a photosensitizer and a sacrificial electron acceptor.Experimental results showed that the activity of each catalyst was strongly dependent on the content of CH3CN in the phosphate buffer,which not only affected the driving force for water oxidation,but also altered the kinetics of the reaction,probably through different mechanisms associated with the O–O bond formation.As a result,dimer2showedsignificantly higher activity than monomer1in the solvent containing a low content of CH3CN,and comparable activities were attained with a high content of CH3CN in the solvent.Under the optimal conditions,complex2achieved a turnover number of638for photocatalytic O2evolution.展开更多
Non-smooth system including impulsive strategies at both fixed and unfixed times are analyzed. For the model with fixed impulsive effects, the global stability of pest eradi- cation periodic solution and the dominance...Non-smooth system including impulsive strategies at both fixed and unfixed times are analyzed. For the model with fixed impulsive effects, the global stability of pest eradi- cation periodic solution and the dominance of dynamic behavior are investigated. This indicates that the model with fixed moments has the potential to protect the natural enemies from extinction, but under some conditions may also serve to extinction of the pest. The second model is constructed according to the practices of IPM, that is, when the pest population reaches the economic injury level, a combination of biological, cultural, and chemical tactics that reduce pests to tolerable levels is used. Numerical investigations imply that there are several different types of periodic solutions and their maximum amplitudes are always less than the given economic threshold. The results also show that the time series at which the IPM strategies are applied are quite complex, which means that the application and realization of IPM in practice are very difficult.展开更多
基金supported by the Belt and Road Initiative by Chinese Academy of Sciencesthe National Natural Science Foundation of China(21673052,11404074)
文摘Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.
基金supported by the National Basic Research Program of China (973 Program, 2014CB239402)the National Natural Science Foundation of China (21476043)+1 种基金the Fundamental Research Funds for the Central Universities (DUT17ZD204)the Swedish Energy Agency and K&A Wallenberg Foundation~~
文摘Binuclear ruthenium complexes bearing the2,2'‐bipyridine‐6,6'‐dicarboxylate(bda)ligand have been demonstrated to be highly active catalysts towards water oxidation with CeIV as an oxidant.However,the catalytic properties of ruthenium dimers have not yet been explored for visible light‐driven water oxidation.Herein,the photocatalytic performance of a dipyridyl propane‐bridged ruthenium dimer2was investigated in comparison with its monomeric precursor,[Ru(bda)(pic)2](1),in CH3CN/phosphate buffer mixed solvent in a three‐component system including a photosensitizer and a sacrificial electron acceptor.Experimental results showed that the activity of each catalyst was strongly dependent on the content of CH3CN in the phosphate buffer,which not only affected the driving force for water oxidation,but also altered the kinetics of the reaction,probably through different mechanisms associated with the O–O bond formation.As a result,dimer2showedsignificantly higher activity than monomer1in the solvent containing a low content of CH3CN,and comparable activities were attained with a high content of CH3CN in the solvent.Under the optimal conditions,complex2achieved a turnover number of638for photocatalytic O2evolution.
文摘Non-smooth system including impulsive strategies at both fixed and unfixed times are analyzed. For the model with fixed impulsive effects, the global stability of pest eradi- cation periodic solution and the dominance of dynamic behavior are investigated. This indicates that the model with fixed moments has the potential to protect the natural enemies from extinction, but under some conditions may also serve to extinction of the pest. The second model is constructed according to the practices of IPM, that is, when the pest population reaches the economic injury level, a combination of biological, cultural, and chemical tactics that reduce pests to tolerable levels is used. Numerical investigations imply that there are several different types of periodic solutions and their maximum amplitudes are always less than the given economic threshold. The results also show that the time series at which the IPM strategies are applied are quite complex, which means that the application and realization of IPM in practice are very difficult.
