The high electrical conductivity and high specific surface area of graphene are traditionally regarded as the most intriguing features for its promise as the electrode material for supercapacitors. In this perspective...The high electrical conductivity and high specific surface area of graphene are traditionally regarded as the most intriguing features for its promise as the electrode material for supercapacitors. In this perspective, we highlight that from the engineering point of view, the unique colloidal chemistry of chemically functionalized graphene is the key property that has made graphene stand out as a promising nanoscale building block for constructing unique nanoporous electrodes for capacitive energy storage, We present several examples to demonstrate bow the non-covalent colloidal forces between graphene sheets can be harnessed to engineer the nanostructure of graphene-based bulk electrodes for supercapacitors based on both the electrical double layer storage and the redox reaction or pseudo-capacitance mechanisms. The colloidal engineering strategy can be extended to enable other nanomaterials to achieve high energy storage performance.展开更多
Homogeneous (ZrO_2)_(0.92)(Sc_2O_3)_(0.08) solid solution in fluorite cubic structure was prepared from the gels with altered molar ratios of citric acid (CA) to metal ions (M) and ethylene glycol (EG) via a polymeriz...Homogeneous (ZrO_2)_(0.92)(Sc_2O_3)_(0.08) solid solution in fluorite cubic structure was prepared from the gels with altered molar ratios of citric acid (CA) to metal ions (M) and ethylene glycol (EG) via a polymerization route (Pechini method). Due to the enhanced chemical homogeneity (high level of mixing of metal ions and ligands) in the polymeric gels, Sc-doped zirconia can be crystallized at temperatures as low as 400 ℃. During the evolution from amorphous gel to the crystallized (ZrO_2)_(0.92)(Sc_2O_3)_(0.08) fine powder, the bonding nature between carboxylate groups and Zr/Sc cations changed: unidentate→bridging→ionic upon calcination. The molar ratios of CA/M (1～4) and CA/EG (0.2～4) were demonstrated to affect the thermal behavior of the gels and thus the particle properties of the derived nanoparticulate oxide powders (including particle size and surface area). The as-sintered sample compacted from the nanosized powders prepared by calcining the gel with the highest content of organics (CA/M=4 and CA/EG=0.2) exhibited the best sinterability and the highest oxide ion conductivity.展开更多
Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm,35 μm and 26 μm,respectively. The surface morphology,porosity,and hyd...Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm,35 μm and 26 μm,respectively. The surface morphology,porosity,and hydrogen sorption properties of Ti-Mo getters formed by MIM using paraffin wax as a principal binder constituent were examined. It has been proven that the powder injection molding is a viable forming technique for porous Ti-Mo getters. The particle size of Ti powders and the powder loading influence...展开更多
Development of the doped lanthanum gallate solid electrolytes in the recent years was reviewed. The structure and oxygen ion transference mechanism were discussed. Effects of alkali earths, transition metals, and impu...Development of the doped lanthanum gallate solid electrolytes in the recent years was reviewed. The structure and oxygen ion transference mechanism were discussed. Effects of alkali earths, transition metals, and impurities on electrical conductivity of the doped lanthanum gallates were also discussed. The applications of doped lanthanum gallate were described. The current problems and corresponding strategies were explored.展开更多
Technological advancements in recent decades have greatly transformed the field of material chemistry.Juxtaposing the accentuating energy demand with the pollution associated,urgent measures are required to ensure ene...Technological advancements in recent decades have greatly transformed the field of material chemistry.Juxtaposing the accentuating energy demand with the pollution associated,urgent measures are required to ensure energy maximization,while reducing the extended experimental time cycle involved in energy production.In lieu of this,the prominence of catalysts in chemical reactions,particularly energy related reactions cannot be undermined,and thus it is critical to discover and design catalyst,towards the optimization of chemical processes and generation of sustainable energy.Most recently,artificial intelligence(AI)has been incorporated into several fields,particularly in advancing catalytic processes.The integration of intensive data set,machine learning models and robotics,provides a very powerful tool in modifying material synthesis and optimization by generating multifarious dataset amenable with machine learning techniques.The employment of robots automates the process of dataset and machine learning models integration in screening intermetallic surfaces of catalyst,with extreme accuracy and swiftness comparable to a number of human researchers.Although,the utilization of robots in catalyst discovery is still in its infancy,in this review we summarize current sway of artificial intelligence in catalyst discovery,briefly describe the application of databases,machine learning models and robots in this field,with emphasis on the consolidation of these monomeric units into a tripartite flow process.We point out current trends of machine learning and hybrid models of first principle calculations(DFT)for generating dataset,which is integrable into autonomous flow process of catalyst discovery.Also,we discuss catalyst discovery for renewable energy related reactions using this tripartite flow process with predetermined descriptors.展开更多
A series of compounds, La 2/3- x Li 3 x MoO 4, were first prepared. Their structures are tetragonal scheelites with the cationic defects. The cell parameters a, c and values of c/a decrease with...A series of compounds, La 2/3- x Li 3 x MoO 4, were first prepared. Their structures are tetragonal scheelites with the cationic defects. The cell parameters a, c and values of c/a decrease with the increasing of the substitution amount (3 x ) of lithium ion. Cationic vacancies are getting more as Li + concentration is lower. The diffusion of lithium ion is predominant. The concentration of charge carriers increases with increasing the substitution amount (3 x ) of lithium ion, meanwhile, the concentration of cationic vacancies decreases. The conductivity approaches the best when the substitution amount (3 x ) of lithium ion is about 0.3. The conductivity of La 0.567 Li 0.3 MoO 4 is 6.5×10 -6 S·cm -1 at room temperature.展开更多
Effects of small amount of Ca doping in La site in LaCoO 3-based oxide on th e synthesis and electrical conductivity were investigated by using X-ray diffra ction (XRD), differential scanning calorimetry and thermogr...Effects of small amount of Ca doping in La site in LaCoO 3-based oxide on th e synthesis and electrical conductivity were investigated by using X-ray diffra ction (XRD), differential scanning calorimetry and thermogravimetry (DSC/TG), or dinary four-probe dc measurement methods. La 0.8Sr 0.2-xCa x Co 0.9Fe 0.1O 3-δ (LSCCF, 0≤x≤0.1) prepared by solid r eact ion synthesis is all of a single phase and the calcined process may be divided i nt o three stages: (1) decomposition of reactants; (2) formation of LaCoO 3-based oxides; and (3) formation of LSCCF solid solution. The maximum of electrical co nductivity of the LSCCF composites is above 100 S·cm -1 and the co nduction me chanism is attributed to the adiabatic-hopping of p-type small polarons.展开更多
La_(0.68)Pb_(0.32)FeO_3 samples annealed at different temperature were prepared using citrate sol-gel method. With increasing of annealing temperature from 200 to 1000 ℃, the samples crystallize to have single-phase ...La_(0.68)Pb_(0.32)FeO_3 samples annealed at different temperature were prepared using citrate sol-gel method. With increasing of annealing temperature from 200 to 1000 ℃, the samples crystallize to have single-phase perovskite structure. However, the sensitivity increases at first due to the improvement of crystallization of the perovskite phase, and finally drops attributed to the larger grain size. The optimal sensitivities for La_(0.68)Pb_(0.32)FeO_3 samples annealed at 400, 600, 800, and 1000 ℃ are 12.14, 14.77, 51.07, and 34.55, respectively.展开更多
Dynamic covalent chemistry has emerged recently to be a powerful tool to construct functional materials.This article reviews the progress in the research and development of dynamic covalent chemistry in gels assembled...Dynamic covalent chemistry has emerged recently to be a powerful tool to construct functional materials.This article reviews the progress in the research and development of dynamic covalent chemistry in gels assembled from small molecules.First dynamic covalent reactions used in gels are reviewed to understand the dynamic covalent bonding.Afterwards the catalogues of dynamic covalent gels are reviewed according to the nature of gelators and the interactions between gelators.Dynamic covalent bonding can be involved to form low molecular weight gelators.Low molecular weight molecules with multiple functional groups react to form dynamic covalent cross-linked polymers and act as gelators.Two catalogues of gels show different properties arising from their different structures.This review aims to illustrate the structure-property relationships of these dynamic covalent gels.展开更多
基金the financial support for the Australian Research Council(FT110100341 and DP140102624)
文摘The high electrical conductivity and high specific surface area of graphene are traditionally regarded as the most intriguing features for its promise as the electrode material for supercapacitors. In this perspective, we highlight that from the engineering point of view, the unique colloidal chemistry of chemically functionalized graphene is the key property that has made graphene stand out as a promising nanoscale building block for constructing unique nanoporous electrodes for capacitive energy storage, We present several examples to demonstrate bow the non-covalent colloidal forces between graphene sheets can be harnessed to engineer the nanostructure of graphene-based bulk electrodes for supercapacitors based on both the electrical double layer storage and the redox reaction or pseudo-capacitance mechanisms. The colloidal engineering strategy can be extended to enable other nanomaterials to achieve high energy storage performance.
文摘Homogeneous (ZrO_2)_(0.92)(Sc_2O_3)_(0.08) solid solution in fluorite cubic structure was prepared from the gels with altered molar ratios of citric acid (CA) to metal ions (M) and ethylene glycol (EG) via a polymerization route (Pechini method). Due to the enhanced chemical homogeneity (high level of mixing of metal ions and ligands) in the polymeric gels, Sc-doped zirconia can be crystallized at temperatures as low as 400 ℃. During the evolution from amorphous gel to the crystallized (ZrO_2)_(0.92)(Sc_2O_3)_(0.08) fine powder, the bonding nature between carboxylate groups and Zr/Sc cations changed: unidentate→bridging→ionic upon calcination. The molar ratios of CA/M (1～4) and CA/EG (0.2～4) were demonstrated to affect the thermal behavior of the gels and thus the particle properties of the derived nanoparticulate oxide powders (including particle size and surface area). The as-sintered sample compacted from the nanosized powders prepared by calcining the gel with the highest content of organics (CA/M=4 and CA/EG=0.2) exhibited the best sinterability and the highest oxide ion conductivity.
文摘Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm,35 μm and 26 μm,respectively. The surface morphology,porosity,and hydrogen sorption properties of Ti-Mo getters formed by MIM using paraffin wax as a principal binder constituent were examined. It has been proven that the powder injection molding is a viable forming technique for porous Ti-Mo getters. The particle size of Ti powders and the powder loading influence...
文摘Development of the doped lanthanum gallate solid electrolytes in the recent years was reviewed. The structure and oxygen ion transference mechanism were discussed. Effects of alkali earths, transition metals, and impurities on electrical conductivity of the doped lanthanum gallates were also discussed. The applications of doped lanthanum gallate were described. The current problems and corresponding strategies were explored.
基金Shenzhen-Hong Kong-Macao Technology Research Programme(Type C,202011033000145)Shenzhen Excellent Science and Technology Innovation Talent Training Project-Outstanding Youth Project(RCJC20200714114435061)Functional Materials Interfaces Genome(FIG)project.
文摘Technological advancements in recent decades have greatly transformed the field of material chemistry.Juxtaposing the accentuating energy demand with the pollution associated,urgent measures are required to ensure energy maximization,while reducing the extended experimental time cycle involved in energy production.In lieu of this,the prominence of catalysts in chemical reactions,particularly energy related reactions cannot be undermined,and thus it is critical to discover and design catalyst,towards the optimization of chemical processes and generation of sustainable energy.Most recently,artificial intelligence(AI)has been incorporated into several fields,particularly in advancing catalytic processes.The integration of intensive data set,machine learning models and robotics,provides a very powerful tool in modifying material synthesis and optimization by generating multifarious dataset amenable with machine learning techniques.The employment of robots automates the process of dataset and machine learning models integration in screening intermetallic surfaces of catalyst,with extreme accuracy and swiftness comparable to a number of human researchers.Although,the utilization of robots in catalyst discovery is still in its infancy,in this review we summarize current sway of artificial intelligence in catalyst discovery,briefly describe the application of databases,machine learning models and robots in this field,with emphasis on the consolidation of these monomeric units into a tripartite flow process.We point out current trends of machine learning and hybrid models of first principle calculations(DFT)for generating dataset,which is integrable into autonomous flow process of catalyst discovery.Also,we discuss catalyst discovery for renewable energy related reactions using this tripartite flow process with predetermined descriptors.
文摘A series of compounds, La 2/3- x Li 3 x MoO 4, were first prepared. Their structures are tetragonal scheelites with the cationic defects. The cell parameters a, c and values of c/a decrease with the increasing of the substitution amount (3 x ) of lithium ion. Cationic vacancies are getting more as Li + concentration is lower. The diffusion of lithium ion is predominant. The concentration of charge carriers increases with increasing the substitution amount (3 x ) of lithium ion, meanwhile, the concentration of cationic vacancies decreases. The conductivity approaches the best when the substitution amount (3 x ) of lithium ion is about 0.3. The conductivity of La 0.567 Li 0.3 MoO 4 is 6.5×10 -6 S·cm -1 at room temperature.
文摘Effects of small amount of Ca doping in La site in LaCoO 3-based oxide on th e synthesis and electrical conductivity were investigated by using X-ray diffra ction (XRD), differential scanning calorimetry and thermogravimetry (DSC/TG), or dinary four-probe dc measurement methods. La 0.8Sr 0.2-xCa x Co 0.9Fe 0.1O 3-δ (LSCCF, 0≤x≤0.1) prepared by solid r eact ion synthesis is all of a single phase and the calcined process may be divided i nt o three stages: (1) decomposition of reactants; (2) formation of LaCoO 3-based oxides; and (3) formation of LSCCF solid solution. The maximum of electrical co nductivity of the LSCCF composites is above 100 S·cm -1 and the co nduction me chanism is attributed to the adiabatic-hopping of p-type small polarons.
基金Project supported by the National Natural Science Foundation of China (59772040)
文摘La_(0.68)Pb_(0.32)FeO_3 samples annealed at different temperature were prepared using citrate sol-gel method. With increasing of annealing temperature from 200 to 1000 ℃, the samples crystallize to have single-phase perovskite structure. However, the sensitivity increases at first due to the improvement of crystallization of the perovskite phase, and finally drops attributed to the larger grain size. The optimal sensitivities for La_(0.68)Pb_(0.32)FeO_3 samples annealed at 400, 600, 800, and 1000 ℃ are 12.14, 14.77, 51.07, and 34.55, respectively.
基金the NSFC(Nos.51573216 and 21273007)the Program for New Century Excellent Talents in University(No.NCET-13-0615)the FRF for the Central Universities(No.16lgjc66)for support
文摘Dynamic covalent chemistry has emerged recently to be a powerful tool to construct functional materials.This article reviews the progress in the research and development of dynamic covalent chemistry in gels assembled from small molecules.First dynamic covalent reactions used in gels are reviewed to understand the dynamic covalent bonding.Afterwards the catalogues of dynamic covalent gels are reviewed according to the nature of gelators and the interactions between gelators.Dynamic covalent bonding can be involved to form low molecular weight gelators.Low molecular weight molecules with multiple functional groups react to form dynamic covalent cross-linked polymers and act as gelators.Two catalogues of gels show different properties arising from their different structures.This review aims to illustrate the structure-property relationships of these dynamic covalent gels.
