1D/2D CeO_(2)/ZnIn_(2)S_(4)Z-scheme异质结光催化剂实现高效可见光分解水制氢

1D/2D CeO_(2)/ZnIn_(2)S_(4)Z-scheme heterojunction photocatalysts for efficient H2 evolution under visible light

开发具有高效电荷转移效率的光催化剂已成为太阳能-氢能转换的关键科学方法.本研究通过在CeO_(2)纳米棒表面原位生长ZnIn_(2)S_(4)纳米片,成功制备了具有Z-scheme异质结的1D/2D CeO_(2)/ZnIn_(2)S_(4)光催化剂.在无助催化剂的情况下,15 wt%CeO_(2)/85 wt%ZnIn_(2)S_(4)样品在可见光下实现了3.29 mmol g^(-1)h-1的最佳H2产量,该值分别比原始ZnIn_(2)S_(4)和CeO_(2)分别高2.7倍和92.6倍.优异的光催化活性可能是由于光生载流子的有效分离和Z-scheme异质结的形成保留了ZnIn_(2)S_(4)中用于产氢的强还原电子.密度泛函理论计算和开尔文探针力显微镜证明了CeO_(2)和ZnIn_(2)S_(4)之间存在内部电场.此外,电子顺磁共振光谱以及原位辐照X射线光电子能谱证实了CeO_(2)O2/ZnIn_(2)S_(4)异质结中的光生载流子按照Zscheme路径转移.这项工作可为开发用于太阳能水分解制氢的高效Zscheme光催化剂提供一些见解.

The development of a high-efficiency photocatalyst having favorable charge transfer has become an important scientific approach for solar-to-fuel conversion.In this study,the one-dimensional(1D)/2D CeO_(2)/ZnIn_(2)S_(4)(ZIS)photocatalyst having a Z-scheme heterojunction has been successfully fabricated using the in situ growth of ZIS nanosheets on the CeO_(2)nanorod surfaces.The optimal H2production rate of 3.29 mmol g^(-1)h-1was achieved with the 15%CeO_(2)/ZIS sample under visible light without any cocatalyst;furthermore,this value was 2.7 and 92.6 times higher than those of pristine ZIS and CeO_(2),respectively.The remarkable photocatalytic activity can be attributed to the efficient separation of photogenerated carriers as well as the formation of the Z-scheme heterojunction,which maintained the strong reduction of electrons in ZIS for H2production.The presence of an internal electric field between CeO_(2)and ZIS has been demonstrated by both density functional theory calculations and Kelvin probe force microscopy.The Z-scheme transfer of photogenerated carriers in the CeO_(2)/ZIS heterojunction has been confirmed by electron paramagnetic resonance spectroscopy and in situ irradiated X-ray photoelectron spectroscopy.This study presents certain insights into the development of efficient Z-scheme photocatalysts for H2evolution from solar water splitting.