The oxygen evolution reaction(OER)is a half-reaction of water electrolysis,and the OER performance of an electrocatalyst is significantly related to its energy conversion efficiency.Due to their high OER activity,tran...The oxygen evolution reaction(OER)is a half-reaction of water electrolysis,and the OER performance of an electrocatalyst is significantly related to its energy conversion efficiency.Due to their high OER activity,transition metal-based nanomaterials have become potential low-cost substitutes for Ir/Ru-based OER electrocatalysts in an alkaline environment.Herein,holey Fe3O4-coupled Ni(OH)2 sheets(Ni(OH)2-Fe H-STs)were easily achieved by a simple mixed-cyanogel hydrolysis strategy.The two-dimensional(2D)Ni(OH)2-Fe H-STs with ca.1 nm thickness have a high specific surface area,abundant unsaturated coordination atoms,and numerous pores,which are highly favorable for electrocatalytic reactions.Meanwhile,the introduction of Fe improves the conductivity and regulates the electronic structure of Ni.Due to their special structural features and synergistic effect between the Fe and Ni atoms,Ni(OH)2-Fe H-STs with an optimal Ni/Fe ratio show excellent OER activity in a 1 M KOH solution,which significantly exceeds that of the commercial RuO2 nanoparticle electrocatalyst.Furthermore,Ni(OH)2-Fe H-STs can be grown on nickel foam(NF),and the resulting material exhibits enhanced OER activity,such as a small overpotential of 200 mV and a small Tafel slope of 56 mV dec−1,than that of Ni(OH)2-Fe H-STs without NF.展开更多
Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and...Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 catalysts.The pore size impacted the spatial distribution of CdS nanoparticles(NPs):CdS tended to deposit on the external surface of mesoporous UiO-66,but spontaneously penetrated into the large cavity of macroporous UiO-66 nanocage.Normalized to unit amount of CdS,the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was~3 folds of that of mesoporous counterpart,and outperformed many other reported state-of-art CdS-based catalysts.A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity,which could shorten the electron-transport distance of NPs-MOFs-reactant,and protect the active CdS NPs from photocorrosion.The finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/MOFs for diverse applications.展开更多
文摘The oxygen evolution reaction(OER)is a half-reaction of water electrolysis,and the OER performance of an electrocatalyst is significantly related to its energy conversion efficiency.Due to their high OER activity,transition metal-based nanomaterials have become potential low-cost substitutes for Ir/Ru-based OER electrocatalysts in an alkaline environment.Herein,holey Fe3O4-coupled Ni(OH)2 sheets(Ni(OH)2-Fe H-STs)were easily achieved by a simple mixed-cyanogel hydrolysis strategy.The two-dimensional(2D)Ni(OH)2-Fe H-STs with ca.1 nm thickness have a high specific surface area,abundant unsaturated coordination atoms,and numerous pores,which are highly favorable for electrocatalytic reactions.Meanwhile,the introduction of Fe improves the conductivity and regulates the electronic structure of Ni.Due to their special structural features and synergistic effect between the Fe and Ni atoms,Ni(OH)2-Fe H-STs with an optimal Ni/Fe ratio show excellent OER activity in a 1 M KOH solution,which significantly exceeds that of the commercial RuO2 nanoparticle electrocatalyst.Furthermore,Ni(OH)2-Fe H-STs can be grown on nickel foam(NF),and the resulting material exhibits enhanced OER activity,such as a small overpotential of 200 mV and a small Tafel slope of 56 mV dec−1,than that of Ni(OH)2-Fe H-STs without NF.
文摘Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 catalysts.The pore size impacted the spatial distribution of CdS nanoparticles(NPs):CdS tended to deposit on the external surface of mesoporous UiO-66,but spontaneously penetrated into the large cavity of macroporous UiO-66 nanocage.Normalized to unit amount of CdS,the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was~3 folds of that of mesoporous counterpart,and outperformed many other reported state-of-art CdS-based catalysts.A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity,which could shorten the electron-transport distance of NPs-MOFs-reactant,and protect the active CdS NPs from photocorrosion.The finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/MOFs for diverse applications.
