Cu_2O/ZnO异质结构纳米线阵列的光电化学性能

Photoelectrochemical Performance of Cu_2O/ZnO Hetero-nanowire Arrays

通过水热法和热还原法合成了Cu2O/ZnO异质结构纳米线阵列,研究了Cu2O/ZnO异质结构纳米线阵列的光电化学性能。与纯的ZnO纳米线阵列光阳极相比,这种Cu2O/ZnO异质结构光阳极在日光辐照时,展现出了更优异的光电化学性能。在1 V vs.Ag/Ag Cl偏压时,异质结构光阳极的光电流密度达到1.5 m A/cm2,是纯ZnO纳米线阵列的2倍多。这种光电化学性能的提高,一方面是由于Cu2O的加入,提高了光阳极对于可见光的吸收效率,增强了光生载流子的密度。另一方面,Cu2O和ZnO之间形成的空间电场加速了光生电子-空穴对的分离,从而提高了复合结构光阳极的光电化学性能。结果表明,用地球上储量丰富的元素合成的金属氧化物异质结,也可以实现利用太阳光分解水制备氢气。

Cu2O/ZnO hetero-nanowire arrays were synthesized by hydrothermal method followed by a thermal reduction process. In contrast to the pure ZnO nanowire array （NWA） photoanodes, the Cu20/ ZnO NWA photoanodes demonstrated superior photoelectrochemical （PEC） performance upon solar illumination. The optical current density of the different structured light anode reaches 1.5 mA/cm2 as 1 V vs. Ag/AgC1, is 2 times more than pure ZnO nanowire arrays. The enhancement was because the introduction of Cu2O enhanced the absorption efficiency of visible light and increased the photogenerated charge carrier concentration. In addition, the space electric field between Cu20 and ZnO accelerated the separation of the photogenerated electron-hole pairs and improved the PEC performance of the heterostructured photoanodes. The results indicate that metallic oxide heterojunction made up of earth-abundant elements can also realize hydrogen generation by solar water splitting.