The energy barrier for the rate-determining step(RDS)is exceptionally critical for the catalytic oxygen evolution reaction(OER)efficiency of an electrocatalyst;however,facilely decreasing the energy barrier of RDS and...The energy barrier for the rate-determining step(RDS)is exceptionally critical for the catalytic oxygen evolution reaction(OER)efficiency of an electrocatalyst;however,facilely decreasing the energy barrier of RDS and realizing the precise manipulation of the reaction process remains challenging.Herein,through constructing a nanosheet assembled sunflower-like Co(OH)_(2) with Ir,Fe codoping,the electronic structure and binding strengths with oxygen-involved intermediates of Co active sites are considerably moderated.First-principles calculations and comprehensive characterizations suggest that Fe and Ir codoping significantly lowers the electrochemical reaction barrier and promotes the OER reaction kinetics by precisely accelerating the formation process of*O.Moreover,the nanosheet-assembled open architectures enable the catalyst with plentiful catalytically active sites and facilitate mass transport and electron transfer.As a result,the optimal electrocatalyst can exhibit outstanding oxygen-evolving activity with an ultralow overpotential of 254 mV at 10 mA cm^(-2).This study realizes the precise manipulation of the reaction energy barrier of OER via Ir,Fe dual doping,which will be a generic paradigm for designing advanced yet cost-effective electrocatalysts.展开更多
Heat denaturation is an important technique in the study of the structure and function of photosynthetic proteins. Heat denaturation of photosystem II (PSII) membrane was studied using circular dichroism (CD) spect...Heat denaturation is an important technique in the study of the structure and function of photosynthetic proteins. Heat denaturation of photosystem II (PSII) membrane was studied using circular dichroism (CD) spectroscopy, differential scanning calorimetry (DSC) and oxygen electrode. Complete loss of oxygen evolving activity of the PSII membrane was observed at temperatures below 45℃ . The decrease of excitonic interaction between chlorophyll molecules occurred more rapidly than the change of the protein secondary structure of the PSII membrane at temperatures above 45℃ . The results indicate that the protein secondary structure of the membrane proteins in PSII membranes is more stable than the excitonic interaction between chlorophyll molecules during heat denaturation.展开更多
基金supported by the start-up funding to H.Xu from Changzhou University(ZMF22020055)grants from Advanced Catalysis and Green Manufacturing Collaborative Innovation Center(ACGM2022-10-01),Changzhou University.
文摘The energy barrier for the rate-determining step(RDS)is exceptionally critical for the catalytic oxygen evolution reaction(OER)efficiency of an electrocatalyst;however,facilely decreasing the energy barrier of RDS and realizing the precise manipulation of the reaction process remains challenging.Herein,through constructing a nanosheet assembled sunflower-like Co(OH)_(2) with Ir,Fe codoping,the electronic structure and binding strengths with oxygen-involved intermediates of Co active sites are considerably moderated.First-principles calculations and comprehensive characterizations suggest that Fe and Ir codoping significantly lowers the electrochemical reaction barrier and promotes the OER reaction kinetics by precisely accelerating the formation process of*O.Moreover,the nanosheet-assembled open architectures enable the catalyst with plentiful catalytically active sites and facilitate mass transport and electron transfer.As a result,the optimal electrocatalyst can exhibit outstanding oxygen-evolving activity with an ultralow overpotential of 254 mV at 10 mA cm^(-2).This study realizes the precise manipulation of the reaction energy barrier of OER via Ir,Fe dual doping,which will be a generic paradigm for designing advanced yet cost-effective electrocatalysts.
基金Supported by the State Key Basic Research and Development Plan (No.G19980 10 10 0 ) the National Natural Science Foundation of China(No.3 9890 3 90 )
文摘Heat denaturation is an important technique in the study of the structure and function of photosynthetic proteins. Heat denaturation of photosystem II (PSII) membrane was studied using circular dichroism (CD) spectroscopy, differential scanning calorimetry (DSC) and oxygen electrode. Complete loss of oxygen evolving activity of the PSII membrane was observed at temperatures below 45℃ . The decrease of excitonic interaction between chlorophyll molecules occurred more rapidly than the change of the protein secondary structure of the PSII membrane at temperatures above 45℃ . The results indicate that the protein secondary structure of the membrane proteins in PSII membranes is more stable than the excitonic interaction between chlorophyll molecules during heat denaturation.
