The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still challenging.Herei...The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still challenging.Herein,a novel strategy was developed to synthesize non-noble metal co-catalyst/solid solution heterojunctions using metal-organic frameworks(MOFs)as a precursor template.By adjusting the content of MOFs,a series of Cu1.8S/ZnxCd1-xS heterojunctions were obtained,and the Cu1.8S(3.7%)/Zn0.35Cd0.65S sample exhibits a maximum hydrogen evolution rate of 14.27 mmol h^(-1) g^(-1) with an apparent quantum yield of 3.7%at 420 nm under visible-light irradiation.Subsequently,the relationship between the heterojunction and photocatalytic activity were investigated by detailed characterizations and density functional theory(DFT)calculations,which reveal that loading Cu1.8S can efficiently extend the light absorption,meanwhile,the electrons can efficiently transfer from Zn0.35Cd0.65S to Cu1.8S,thus resulting more photogenerated electrons participating in surface reactions.This result can be valuable inspirations for the exploitation of advanced materials using rationally designed nanostructures for solar energy conversion.展开更多
Digenite(Cu_(1.8)S)as a potential p-type thermoelectric(TE)material has attracted extensive attention due to its environmental benign,abundant resources and low cost of component elements.In this study,the TE properti...Digenite(Cu_(1.8)S)as a potential p-type thermoelectric(TE)material has attracted extensive attention due to its environmental benign,abundant resources and low cost of component elements.In this study,the TE properties of MnxCu_(1.8)S bulk samples prepared by mechanical alloying(MA)combined with spark plasma sintering(SPS)were investigated.Doping Mn would initially substitute Cu and tune the band structure of Cu1.8S with an enlarged band gap Eg.However,if Mn content is beyond the solubility limit of x=0.01 in Cu1.8S will cause the formation of MnS,which contributes to the formation of Cu-rich phases at 0.02 ≤x≤ 0.08.Benefiting from the synergetic scattering effect of point defects(Mn Cu,V_(S))and MnS,Cu1.96S,Cu1.97S,Cu2S phases,the lowest thermal conductivity k value of 0.75 W m^(-1) K^(-1) was obtained at 773 K for Mn0.08Cu1.8S.Along with the decreased k,the highest figure of merit ZT value of 0.92 at 773 K achieved in Mn0.08Cu1.8S bulk sample.A maximum engineering ZTeng of 0.3 and its efficiency hmax of about 6%were obtained at 323e773 K,which is almost 3 times than that of the pristine Cu1.8S(ηmax=2.2%).Introducing Mn in Cu1.8S is an effective and convenient strategy to improve TE performance.展开更多
基金the financially support by the National Natural Science Foundation of China as general projects(Nos.21722702 and 21874099)the Tianjin Commission of Science and Technology as key technologies R&D projects(Nos.18YFZCSF00730,18YFZCSF00770 and 18ZXSZSF00230)+1 种基金National Key Basic Research Program of China(No.2017YFA0403402)Science and Technology Research Projects of Colleges and Universities in Hebei province(No.ZD2020149)。
文摘The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still challenging.Herein,a novel strategy was developed to synthesize non-noble metal co-catalyst/solid solution heterojunctions using metal-organic frameworks(MOFs)as a precursor template.By adjusting the content of MOFs,a series of Cu1.8S/ZnxCd1-xS heterojunctions were obtained,and the Cu1.8S(3.7%)/Zn0.35Cd0.65S sample exhibits a maximum hydrogen evolution rate of 14.27 mmol h^(-1) g^(-1) with an apparent quantum yield of 3.7%at 420 nm under visible-light irradiation.Subsequently,the relationship between the heterojunction and photocatalytic activity were investigated by detailed characterizations and density functional theory(DFT)calculations,which reveal that loading Cu1.8S can efficiently extend the light absorption,meanwhile,the electrons can efficiently transfer from Zn0.35Cd0.65S to Cu1.8S,thus resulting more photogenerated electrons participating in surface reactions.This result can be valuable inspirations for the exploitation of advanced materials using rationally designed nanostructures for solar energy conversion.
基金supported by National Key R&D Program of China(Grant No.2018YFB0703600)the National Natural Science Foundation of China(Grant No.11474176)。
文摘Digenite(Cu_(1.8)S)as a potential p-type thermoelectric(TE)material has attracted extensive attention due to its environmental benign,abundant resources and low cost of component elements.In this study,the TE properties of MnxCu_(1.8)S bulk samples prepared by mechanical alloying(MA)combined with spark plasma sintering(SPS)were investigated.Doping Mn would initially substitute Cu and tune the band structure of Cu1.8S with an enlarged band gap Eg.However,if Mn content is beyond the solubility limit of x=0.01 in Cu1.8S will cause the formation of MnS,which contributes to the formation of Cu-rich phases at 0.02 ≤x≤ 0.08.Benefiting from the synergetic scattering effect of point defects(Mn Cu,V_(S))and MnS,Cu1.96S,Cu1.97S,Cu2S phases,the lowest thermal conductivity k value of 0.75 W m^(-1) K^(-1) was obtained at 773 K for Mn0.08Cu1.8S.Along with the decreased k,the highest figure of merit ZT value of 0.92 at 773 K achieved in Mn0.08Cu1.8S bulk sample.A maximum engineering ZTeng of 0.3 and its efficiency hmax of about 6%were obtained at 323e773 K,which is almost 3 times than that of the pristine Cu1.8S(ηmax=2.2%).Introducing Mn in Cu1.8S is an effective and convenient strategy to improve TE performance.
