Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their po...Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their potential in promoting CO_(2)reduction reaction(CO_(2)RR),however,their low phase stability has limited their application perspective.Herein,we present a reduced graphene oxide(rGO)wrapped CsPbI_3 perovskite nanocrystal(NC)CO_(2)RR catalyst(CsPbI_3/rGO),demonstrating enhanced stability in the aqueous electrolyte.The CsPbI_3/rGO catalyst exhibited>92%Faradaic efficiency toward formate production at a CO_(2)RR current density of~12.7 mA cm^(-2).Comprehensive characterizations revealed the superior performance of the CsPbI_3/rGO catalyst originated from the synergistic effects between the CsPbI_3 NCs and rGO,i.e.,rGO stabilized theα-CsPbI_3 phase and tuned the charge distribution,thus lowered the energy barrier for the protonation process and the formation of~*HCOO intermediate,which resulted in high CO_(2)RR selectivity toward formate.This work shows a promising strategy to rationally design robust metal halide perovskites for achieving efficient CO_(2)RR toward valuable fuels.展开更多
Deposition of platinum(Pt)monolayers(PtML)on Au substrate represents a robust strategy to maximally utilize the Pt atoms and meanwhile achieve high catalytic activity towards methanol oxidation reaction for direct met...Deposition of platinum(Pt)monolayers(PtML)on Au substrate represents a robust strategy to maximally utilize the Pt atoms and meanwhile achieve high catalytic activity towards methanol oxidation reaction for direct methanol fuel cells owing to a substrate-induced tensile strain effect.However,recent studies showed that Pt(ML)on Au substrate are far from perfect smooth monoatomic layer,but actually exhibited three-dimensional nanoclusters.Moreover,the Pt(ML)suffered from severe structural instability and thus activity degradation during long-term electrocatalysis.To regulate the growth of Pt(ML)Au surface and also to improve its structural stability,we exploit dealloyed AuCu core-shell nanoparticles as a new substrate for depositing Pt(ML).By using high-resolution scanning transmission electron microscopy and energy dispersive X-ray elemental mapping combined with electrochemical characte rizations,we reveal that the dealloyed AuCu core-shell nanoparticles can effectively promote the deposition of Pt(ML)closer to a smooth monolayer structure,thus leading to a higher utilization efficiency of Pt and higher intrinsic activity towards methanol oxidation compared to those on pure Au nanoparticles.Moreover,the Pt(ML)deposited on the AuCu core-shell NPs showed substa ntially enhanced stability compared to those on pure Au NPs during long-term electrocatalysis over several hours,during which segregation of Cu to the Au/Pt interface was revealed and suggested to play an important role in stabilizing the Pt(ML)catalysts.展开更多
基金financial support by Australian Research Council(ARC)supported by the generous funding from Science and Engineering faculty,QUT。
文摘Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their potential in promoting CO_(2)reduction reaction(CO_(2)RR),however,their low phase stability has limited their application perspective.Herein,we present a reduced graphene oxide(rGO)wrapped CsPbI_3 perovskite nanocrystal(NC)CO_(2)RR catalyst(CsPbI_3/rGO),demonstrating enhanced stability in the aqueous electrolyte.The CsPbI_3/rGO catalyst exhibited>92%Faradaic efficiency toward formate production at a CO_(2)RR current density of~12.7 mA cm^(-2).Comprehensive characterizations revealed the superior performance of the CsPbI_3/rGO catalyst originated from the synergistic effects between the CsPbI_3 NCs and rGO,i.e.,rGO stabilized theα-CsPbI_3 phase and tuned the charge distribution,thus lowered the energy barrier for the protonation process and the formation of~*HCOO intermediate,which resulted in high CO_(2)RR selectivity toward formate.This work shows a promising strategy to rationally design robust metal halide perovskites for achieving efficient CO_(2)RR toward valuable fuels.
基金financial supports by National Natural Science Foundation of China(NSFC,Nos.21573123,51622103)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01N111)+1 种基金Guangdong Natural Science Foundation for Distinguished Young Scholars(No.2016A030306035)Basic Research Program of Shenzhen(No.JCYJ20160531194754308)in China。
文摘Deposition of platinum(Pt)monolayers(PtML)on Au substrate represents a robust strategy to maximally utilize the Pt atoms and meanwhile achieve high catalytic activity towards methanol oxidation reaction for direct methanol fuel cells owing to a substrate-induced tensile strain effect.However,recent studies showed that Pt(ML)on Au substrate are far from perfect smooth monoatomic layer,but actually exhibited three-dimensional nanoclusters.Moreover,the Pt(ML)suffered from severe structural instability and thus activity degradation during long-term electrocatalysis.To regulate the growth of Pt(ML)Au surface and also to improve its structural stability,we exploit dealloyed AuCu core-shell nanoparticles as a new substrate for depositing Pt(ML).By using high-resolution scanning transmission electron microscopy and energy dispersive X-ray elemental mapping combined with electrochemical characte rizations,we reveal that the dealloyed AuCu core-shell nanoparticles can effectively promote the deposition of Pt(ML)closer to a smooth monolayer structure,thus leading to a higher utilization efficiency of Pt and higher intrinsic activity towards methanol oxidation compared to those on pure Au nanoparticles.Moreover,the Pt(ML)deposited on the AuCu core-shell NPs showed substa ntially enhanced stability compared to those on pure Au NPs during long-term electrocatalysis over several hours,during which segregation of Cu to the Au/Pt interface was revealed and suggested to play an important role in stabilizing the Pt(ML)catalysts.