Hierarchical microspheres of a graphene oxide（GO） coupled to N‐doped（BiO）2CO3 composite（N‐BOC‐GO） was synthesized by a simple hydrothermal approach. The N‐BOC‐GO composite gave enhancement in photocatalytic...Hierarchical microspheres of a graphene oxide（GO） coupled to N‐doped（BiO）2CO3 composite（N‐BOC‐GO） was synthesized by a simple hydrothermal approach. The N‐BOC‐GO composite gave enhancement in photocatalytic activity compared to the pure BOC and N‐BOC samples. With 1.0wt% GO, 62% NO removal was obtained with N‐BOC‐GO. The factors enhancing the photocatalytic performance were the high electron‐withdrawing ability and high conductivity of GO and improved visible light‐harvesting ability of N‐BOC‐GO with a 3D hierarchical architecture due to the surface scattering and reflecting（SSR） effect. An effective charge transfer from N‐BOC to GO was demonstrated by the much weakened photoluminescene intensity of the N‐BOC‐GO composite. This work highlights the potential application of GO‐based photocatalysts in air purification.展开更多
The design and synthesis of high‐performance and low‐cost electrocatalysts for the hydrogen evolution reaction(HER),a key half‐reaction in water electrolysis,are essential.Owing to their modest hydrogen adsorption ...The design and synthesis of high‐performance and low‐cost electrocatalysts for the hydrogen evolution reaction(HER),a key half‐reaction in water electrolysis,are essential.Owing to their modest hydrogen adsorption energy,ruthenium(Ru)‐based nanomaterials are considered outstanding candidates to replace the expensive platinum(Pt)‐based HER electrocatalysts.In this study,we developed an adsorption‐pyrolysis method to construct nitrogen(N)‐doped graphene aerogel(N‐GA)‐supported ultrafine Ru nanocrystal(Ru‐NC)nanocomposites(Ru‐NCs/N‐GA).The particle size of the Ru‐NCs and the conductivity of the N‐GA substrate can be controlled by varying the pyrolysis temperature.Optimal experiments reveal revealed that 10 wt%Ru‐NCs/N‐GA nanocomposites require overpotentials of only 52 and 36 mV to achieve a current density of 10 mA cm^(−2) in 1 mol/L HClO4 and 1 mol/L KOH electrolytes for HER,respectively,which is comparable to 20 wt%Pt/C electrocatalyst.Benefiting from the ultrafine size and uniform dispersion of the Ru‐NCs,the synergy between Ru and the highly conductive substrate,and the anchoring effect of the N atom,the Ru‐NCs/N‐GA nanocomposites exhibit excellent activity and durability in the pH‐universal HER,thereby opening a new avenue for the production of commercial HER electrocatalysts.展开更多
We report rational design and syntheses of ternary noble metal-metalloid-nonmetal alloy nanowires(NWs)as a novel electrocatalyst for electrochemical ethanol oxidation reaction(EOR).This novel electrocatalyst is formed...We report rational design and syntheses of ternary noble metal-metalloid-nonmetal alloy nanowires(NWs)as a novel electrocatalyst for electrochemical ethanol oxidation reaction(EOR).This novel electrocatalyst is formed in an aqueous solution via anisotropic nucleation and growth of ternary PdBP alloy NWs along assembled cylinder template of Plurolic F127 on a nitrogen-functionalized graphene support(denoted as PdBP NWs@N-G).We find that uniformly alloying B and P intrinsically modulates the electronic states of Pd catalyst and also introduces new functions into the catalyst,while NW structure supported on the N-G exposes more electrocatalytic active sites and accelerates electron/mass transfers.Such add-in synergies of PdBP NWs@N-G kinetically facilitate the removal and/or further oxidation of CO-based poisoning intermediates,thus remarkably enhancing the electrocatalytic EOR performance.They exhibit a high mass activity of 4.15 A mgPd^-1 and superior cycling and chronoamperometric stability for electrocatalytic EOR,much better than previously reported monometallic Pd-based nanocatalysts.More interestingly,this design strategy can be easily extended to develop more sophisticated NWs catalysts with more compositions(for example quaternary PdCuBP NWs@N-G)that further tunes the electronic and bifuntional effects for various desired catalysis and electrocatalysis.展开更多
基金supported by the National Natural Science Foundation of China(21277097)the Key Projects in the National Science&Technology Pillar Program during the 12th Five-Year Plan Period(2012BAJ21B01)~~
文摘Hierarchical microspheres of a graphene oxide（GO） coupled to N‐doped（BiO）2CO3 composite（N‐BOC‐GO） was synthesized by a simple hydrothermal approach. The N‐BOC‐GO composite gave enhancement in photocatalytic activity compared to the pure BOC and N‐BOC samples. With 1.0wt% GO, 62% NO removal was obtained with N‐BOC‐GO. The factors enhancing the photocatalytic performance were the high electron‐withdrawing ability and high conductivity of GO and improved visible light‐harvesting ability of N‐BOC‐GO with a 3D hierarchical architecture due to the surface scattering and reflecting（SSR） effect. An effective charge transfer from N‐BOC to GO was demonstrated by the much weakened photoluminescene intensity of the N‐BOC‐GO composite. This work highlights the potential application of GO‐based photocatalysts in air purification.
文摘The design and synthesis of high‐performance and low‐cost electrocatalysts for the hydrogen evolution reaction(HER),a key half‐reaction in water electrolysis,are essential.Owing to their modest hydrogen adsorption energy,ruthenium(Ru)‐based nanomaterials are considered outstanding candidates to replace the expensive platinum(Pt)‐based HER electrocatalysts.In this study,we developed an adsorption‐pyrolysis method to construct nitrogen(N)‐doped graphene aerogel(N‐GA)‐supported ultrafine Ru nanocrystal(Ru‐NC)nanocomposites(Ru‐NCs/N‐GA).The particle size of the Ru‐NCs and the conductivity of the N‐GA substrate can be controlled by varying the pyrolysis temperature.Optimal experiments reveal revealed that 10 wt%Ru‐NCs/N‐GA nanocomposites require overpotentials of only 52 and 36 mV to achieve a current density of 10 mA cm^(−2) in 1 mol/L HClO4 and 1 mol/L KOH electrolytes for HER,respectively,which is comparable to 20 wt%Pt/C electrocatalyst.Benefiting from the ultrafine size and uniform dispersion of the Ru‐NCs,the synergy between Ru and the highly conductive substrate,and the anchoring effect of the N atom,the Ru‐NCs/N‐GA nanocomposites exhibit excellent activity and durability in the pH‐universal HER,thereby opening a new avenue for the production of commercial HER electrocatalysts.
基金supported by Natural Science Foundation of Jiangsu Province(BK20180723,BK20191366)Jiangsu Specially Appointed Professor Plan+2 种基金the Program of Jiangsu Province Innovation TeamPriority Academic Program Development of Jiangsu Higher Education InstitutionsNational and Local Joint Engineering Research Center of Biomedical Functional Materials。
文摘We report rational design and syntheses of ternary noble metal-metalloid-nonmetal alloy nanowires(NWs)as a novel electrocatalyst for electrochemical ethanol oxidation reaction(EOR).This novel electrocatalyst is formed in an aqueous solution via anisotropic nucleation and growth of ternary PdBP alloy NWs along assembled cylinder template of Plurolic F127 on a nitrogen-functionalized graphene support(denoted as PdBP NWs@N-G).We find that uniformly alloying B and P intrinsically modulates the electronic states of Pd catalyst and also introduces new functions into the catalyst,while NW structure supported on the N-G exposes more electrocatalytic active sites and accelerates electron/mass transfers.Such add-in synergies of PdBP NWs@N-G kinetically facilitate the removal and/or further oxidation of CO-based poisoning intermediates,thus remarkably enhancing the electrocatalytic EOR performance.They exhibit a high mass activity of 4.15 A mgPd^-1 and superior cycling and chronoamperometric stability for electrocatalytic EOR,much better than previously reported monometallic Pd-based nanocatalysts.More interestingly,this design strategy can be easily extended to develop more sophisticated NWs catalysts with more compositions(for example quaternary PdCuBP NWs@N-G)that further tunes the electronic and bifuntional effects for various desired catalysis and electrocatalysis.
