Identifying the Zn-Co binary as a robust bifunctional electrocatalyst in oxygen reduction and evolution reactions via shifting the apexes of the volcano plot

The performance of an electrocatalyst is closely correlated with the binding strength of key oxygencontaining intermediates,i.e.,*OOH,*O and*OH,in the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Facile strategies to achieve favorable binding strength of these oxygen-containing species are urgently demanded,yet it still remains great challenges.Herein,the Zn-Co bimetallic isolation,which serves as an ideal model,is studied systematically by the density functional theory(DFT).Reaction activity volcano plots are built from 48 models,among them the ZnCoN6-gra(I)configuration is confirmed to be the most stable,featured of the strongest interaction with the oxygen-containing species.Optimal △G*O(free energy change of an atomic oxygen containing intermediate)is facilitated,which effectively drifts the volcano peaks of ORR and OER closer to each other,enabling promising bifunctional catalyst.Moreover,the small overpotential in the simulation of protonation and oxidation by hydroxy groups rationalizes the durability of the catalyst in both acid and alkaline media.

DNA-assisted rational design of BaF_2 linear and erythrocyteshaped nanocrystals

The synthesis of inorganic materials with special morphologies with the assistance of biological molecules is a potential development in the field of controllable growth and assembly of nanomaterials. In this paper, BaF_2 nanocrystals in patterns of well-defined linear and erythrocyte-shaped structure were synthesized with the assistance of Escherichia coli DNA. Morphology and the arrangement of BaF_2 particles on DNA were controllable by altering the reaction condition. Square nanoparticles arranged in linear chains were gained with the assistance of normal DNA; while, erythrocyte-shaped BaF_2 nanospheres were synthesized with the assistance of denatured DNA. Besides, the influences of solvent, reaction temperature, concentration of reactants and the heating time on the morphology of the BaF_2 particles were studied.

Identifying quasi-2D and 1D electrides in yttrium and scandium chlorides via geometrical identification

Developing and understanding electron-rich electrides offers a promising opportunity for a variety of electronic and catalytic applications.Using a geometrical identification strategy,here we identify a new class of electride material,yttrium/scandium chlorides Y(Sc)_(x)Cl_(y)(yx<2).Anionic electrons are found in the metal octahedral framework topology.The diverse electronic dimensionality of these electrides is quantified explicitly by quasi-two-dimensional(2D)electrides for[YCl]^(+)∙e−and[ScCl]^(+∙)e−and one-dimensional(1D)electrides for[Y_(2)Cl_(3)]^(+)∙e−,[Sc_(7)Cl_(10)]^(+)∙e−,and[Sc5Cl8]2+∙2e−with divalent metal elements(Sc^(2+):3d^(1) and Y^(2+):4d^(1)).The localized anionic electrons were confined within the inner-layer spaces,rather than inter-layer spaces that are observed in A_(2)B-type 2D electrides,e.g.Ca_(2)N.Moreover,when hydrogen atoms are introduced into the host structures to form YClH and Y2Cl3H,the generated phases transform to conventional ionic compounds but exhibited a surprising reduction of work function,arising from the increased Fermi level energy,contrary to the conventional electrides reported so far.Y_(2C)l_(3) was experimentally confirmed to be a semiconductor with a band gap of 1.14 eV.These results may help to promote the rational design and discovery of new electride materials for further technological applications.

Simultaneous structure and luminescence property control of barium carbonate nanocrystals through small amount of lanthanide doping

Rare earth doping has been widely applied in many functional nanomaterials with desirable properties and functions,which would have a significant effect on the growth process of the materials.However,the controlling strategy is limited into high concentration of lanthanide doping,which produces concentration quenching of the lanthanide ion luminescence with an increase in the Ln^(3+)concentration,resulting in lowering the fluorescence quantum yield of lanthanide ion.Herein,for the first time,we demonstrate simultaneous control of the structures and luminescence properties of BaCO_3nanocrystals via a small amount of Tb^(3+)doping strategy.In fact,Tb^(3+)would partially occupy Ba^(2+)sites,resulting in the changes to the structures of the BaCO_3nanocrystals,which is primarily determined by charge modulation,including the contributions from the surfaces of crystal nuclei and building blocks.These structurally modified nanocrystals exhibit tunable luminescence properties,thus emerging as potential candidates for photonic devices such as light-emitting diodes and color displays.

A universal synthesis of N,S,Cl-doped carbon materials directly from dye waste liquid for high performance lithium storage

The complicated structured dyes produced by the textile industry have become a serious problem in the last few decades,which can be attributed to their stable chemical structures and difficult to degrade.Therefore,in this article,we described a method to fix dye macromolecules by flocculation process and then transform the colloid to N,S,Cl-doped porous carbon materials.This material can effectively improve the capacity and cycle stability of lithium ion batteries,and recycle the dyes in the water.The N,S,Cl-doped porous carbon materials show a superior electrocatalytic performance of 473.5 mAhg^(−1) at the current density of 100 mAg^(−1) after 60 cycles.The present work combines the lithium ion batteries with dyes waste treatment and has a broad prospect for development.