rGO空间限域生长超薄In_(2)S_(3)纳米片用于构建高效准一维Sb_(2)Se_(3)基异质结光阴极

rGO spatially confined growth of ultrathin In_(2)S_(3)nanosheets for construction of efficient quasi-one-dimensional Sb_(2)Se_(3)-based heterojunction photocathodes

硒化锑(Sb_(2)Se_(3))属于窄带隙半导体材料,具有良好的光吸收特性,已逐渐应用于光电催化领域.独特的一维(Sb_(4)Se_(6))_(n)带状结构单元连接方式,使其载流子传输具有高度各向异性.本文通过气相输运沉积法和原位水热法成功构建了还原氧化石墨烯(rGO)修饰的准一维Sb_(2)Se_(3)@In_(2)S_(3)光陷阱异质结.研究结果表明,在rGO空间限域效应下,原位生长的非层状In_(2)S_(3)纳米片厚度从30 nm减小到10 nm,显著增加了光电极的电化学活性比表面积,进一步增强了光陷阱纳米结构对光的捕获能力.rGO和超薄In_(2)S_(3)纳米片共同修饰的准一维毛刷状Sb_(2)Se_(3)@In_(2)S_(3)-rGO纳米棒光电极在0 V(相对于可逆氢电极)的外加偏压下,光电流密度可达1.169 m A cm^(-2),约是Sb_(2)Se_(3)@In_(2)S_(3)和单体Sb_(2)Se_(3)的2倍和16倍,且稳定性良好,在中性条件下平均产氢速率为16.59μmol cm^(-2)h^(-1).实验结果和理论计算均表明,Ⅱ型异质结电荷传输方式是其光电化学增强的物理机制.以上工作为设计基于rGO修饰的复合光电极用于光电化学领域的研究提供了崭新的思路.

Antimony selenide(Sb_(2)Se_(3))is a narrow-bandgap semiconductor that has been increasingly used as an excellent light-harvesting material in photoelectrocatalysis.The unique connections of the one-dimensional(Sb_(4)Se_(6))_(n)ribbon structural units determine the high anisotropy of their carrier transport.In this study,a reduced graphene oxide(rGO)-modified quasi-one-dimensional Sb_(2)Se_(3)@In_(2)S_(3)light-trapping heterostructure was successfully constructed by vapor transport deposition followed by an in situ hydrothermal method.The results showed that the thickness of the in situ grown nonlayered In_(2)S_(3)nanosheets was significantly reduced from 30 to 10 nm under the space-confinement effect of rGO,facilitating the construction of light-trapping nanostructures and increasing the electrochemically active surface area of the photoelectrode.The quasi-one-dimensional Sb_(2)Se_(3)@In_(2)S_(3)-rGO nanorod photoelectrode achieved a higher photocurrent density(1.169 m A cm^(-2)),which was 2 and 16 times higher than that of Sb_(2)Se_(3)@In_(2)S_(3)and pristine Sb_(2)Se_(3),respectively.The ultrathin In_(2)S_(3)nanosheets were co-modified with rGO nanosheets to fabricate a brush-like composite photoelectrode that exhibited favourable stability with an average hydrogen production rate of 16.59μmol cm^(-2)h^(-1)under neutral conditions.The experimental results and theoretical calculations both showed that the significant improvement in photoelectrochemical performance can be perfectly explained by the type-Ⅱheterojunction mechanism.This study provides a new exploration to design rGO-modified composite photoelectrodes for photoelectrochemical applications.