Charge separation is critical for achieving efficient solar-to-hydrogen conversion,whereas piezoelectric-enhanced photoelectrochemical(PEC)systems can effectively modulate band bending and charge migration.Herein,we d...Charge separation is critical for achieving efficient solar-to-hydrogen conversion,whereas piezoelectric-enhanced photoelectrochemical(PEC)systems can effectively modulate band bending and charge migration.Herein,we design an n-TiO_(2)/Ba TiO_(3)/p-TiO_(2)(TBTm)heterojunction in which the piezoelectric Ba TiO_(3) layer is sandwiched between n-TiO_(2)and p-TiO_(2).The built-in electric field of TBTm can provide a strong driving force to accelerate carrier separation and prolong carrier lifetime.Consequently,the TBT3 achieves a prominent photocurrent density,as high as 2.13 m A cm^(-2)at 1.23 V versus reversible hydrogen electrode(RHE),which is 2.4-and 1.5-times higher than TiO_(2) and TiO_(2)–Ba TiO_(3) heterojunction,respectively.Driven by mechanical deformation,the induced dipole polarization can further regulate built-in electric fields,and the piezoelectric photocurrent density of TBT3-800 is 2.84 times higher than TiO_(2) at 1.23 V vs.RHE due to the construction of piezoelectric-heterostructures.This work provides a piezoelectric polarization strategy for modulating the built-in electric field of heterojunction for PEC system.展开更多
基金the support from the National Natural Science Foundation of China(22222808,21978200,22161142002)the Joint Research Programs of National Natural Science Foundation of China and Pakistan Science Foundation(PSF-NSFC-IV/Phy/P-PU(31))the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘Charge separation is critical for achieving efficient solar-to-hydrogen conversion,whereas piezoelectric-enhanced photoelectrochemical(PEC)systems can effectively modulate band bending and charge migration.Herein,we design an n-TiO_(2)/Ba TiO_(3)/p-TiO_(2)(TBTm)heterojunction in which the piezoelectric Ba TiO_(3) layer is sandwiched between n-TiO_(2)and p-TiO_(2).The built-in electric field of TBTm can provide a strong driving force to accelerate carrier separation and prolong carrier lifetime.Consequently,the TBT3 achieves a prominent photocurrent density,as high as 2.13 m A cm^(-2)at 1.23 V versus reversible hydrogen electrode(RHE),which is 2.4-and 1.5-times higher than TiO_(2) and TiO_(2)–Ba TiO_(3) heterojunction,respectively.Driven by mechanical deformation,the induced dipole polarization can further regulate built-in electric fields,and the piezoelectric photocurrent density of TBT3-800 is 2.84 times higher than TiO_(2) at 1.23 V vs.RHE due to the construction of piezoelectric-heterostructures.This work provides a piezoelectric polarization strategy for modulating the built-in electric field of heterojunction for PEC system.
