Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and c...Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.展开更多
A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead o...A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with a piperazine's derivatives, which proceeds with very high regioselectivity.展开更多
Zincophilic property and high electrical conductivity are both very important parameters to design novel Zn anode for aqueous Zn-ion batteries(AZIBs).However,single material is difficult to exhibit zincophilic propert...Zincophilic property and high electrical conductivity are both very important parameters to design novel Zn anode for aqueous Zn-ion batteries(AZIBs).However,single material is difficult to exhibit zincophilic property and high electrical conductivity at the same time.Herein,originating from theoretical calculation,a zincophilic particle regulation strategy is proposed to address these limitations and carbon coated Na_(3)V_(2)(PO_(4))_(3)is taken as an example to be a protective layer on zinc metal(NVPC@Zn).Na_(3)V_(2)(PO_(4))_(3)(NVP)is a common cathode material for Zn-ion batteries,which is zincophilic.Carbon materials not only offer an electron pathway to help Zn deposition onto NVPC surface,but also enhance the zinc nucleophilicity of Na_(3)V_(2)(PO_(4))_(3).Hence,this hybrid coating layer can tune zinc deposition and resist side reactions such as hydrogen generation and Zn metal corrosion.Experimentally,a symmetrical battery with NVPC@Zn electrode displays highly reversible plating/stripping behavior with a long cycle lifespan over 1800 h at2 mA cm^(-2),much better than carbon and Na_(3)V_(2)(PO_(4))_(3)solely modified Zn electrodes.When the Na_(3)V_(2)(PO_(4))_(3)is replaced with zincophobic Al2O3or zincophilic V2O3,the stability of the modified zinc anodes is also prolonged.This strategy expands the option of zincophilic materials and provides a general and effective way to stabilize the Zn electrode.展开更多
We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of d...We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of durability and the probability of their formation. We performed the light fastness calculations of the monoazopyridone dyes. Using the semi-empirical methods of quantum chemistry AM1 and PM3, the reactivity indicators of superdelocalisability (SrE(N)) and the electron density distribution in ground state on the highest occupied HOMO orbital and the lowest unoccupied excited state LUMO in 2-pyridone phenylazo derivatives were calculated. Superdelocalisability coefficients enable the stability to oxidising agents of various chemical molecules depending on the tautomeric forms in which they may occur. The results of the electron density calculations at the HOMO and LUMO boundary orbitals allow to determine the tendency to electrophilic attack with singlet oxygen 1O2 or nucleophilic attack of the superoxide anion O2•−on a specific atom in the molecule. The structure of the dyes was optimised with MM+, MD and AM1 or PM3 until a constant energy value was achieved with a convergence criterion of 0.01 kcal/mol.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,No.22078052)the Fundamental Research Funds for the Central Universities(DUT22ZD207,DUT22LAB612)。
文摘Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.
文摘A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with a piperazine's derivatives, which proceeds with very high regioselectivity.
基金financially supported by the National Key Research and Development Program of China(2022YFB3803600)the Fundamental Research Funds for the Central Universities(30106200463 and CCNU22CJ017)+1 种基金the National Natural Science Foundation of China(U20A20246)the Graduate Education Innovation Grant from Central China Normal University,China(20210407032)。
文摘Zincophilic property and high electrical conductivity are both very important parameters to design novel Zn anode for aqueous Zn-ion batteries(AZIBs).However,single material is difficult to exhibit zincophilic property and high electrical conductivity at the same time.Herein,originating from theoretical calculation,a zincophilic particle regulation strategy is proposed to address these limitations and carbon coated Na_(3)V_(2)(PO_(4))_(3)is taken as an example to be a protective layer on zinc metal(NVPC@Zn).Na_(3)V_(2)(PO_(4))_(3)(NVP)is a common cathode material for Zn-ion batteries,which is zincophilic.Carbon materials not only offer an electron pathway to help Zn deposition onto NVPC surface,but also enhance the zinc nucleophilicity of Na_(3)V_(2)(PO_(4))_(3).Hence,this hybrid coating layer can tune zinc deposition and resist side reactions such as hydrogen generation and Zn metal corrosion.Experimentally,a symmetrical battery with NVPC@Zn electrode displays highly reversible plating/stripping behavior with a long cycle lifespan over 1800 h at2 mA cm^(-2),much better than carbon and Na_(3)V_(2)(PO_(4))_(3)solely modified Zn electrodes.When the Na_(3)V_(2)(PO_(4))_(3)is replaced with zincophobic Al2O3or zincophilic V2O3,the stability of the modified zinc anodes is also prolonged.This strategy expands the option of zincophilic materials and provides a general and effective way to stabilize the Zn electrode.
文摘We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of durability and the probability of their formation. We performed the light fastness calculations of the monoazopyridone dyes. Using the semi-empirical methods of quantum chemistry AM1 and PM3, the reactivity indicators of superdelocalisability (SrE(N)) and the electron density distribution in ground state on the highest occupied HOMO orbital and the lowest unoccupied excited state LUMO in 2-pyridone phenylazo derivatives were calculated. Superdelocalisability coefficients enable the stability to oxidising agents of various chemical molecules depending on the tautomeric forms in which they may occur. The results of the electron density calculations at the HOMO and LUMO boundary orbitals allow to determine the tendency to electrophilic attack with singlet oxygen 1O2 or nucleophilic attack of the superoxide anion O2•−on a specific atom in the molecule. The structure of the dyes was optimised with MM+, MD and AM1 or PM3 until a constant energy value was achieved with a convergence criterion of 0.01 kcal/mol.
