Passivation of ZnSe nanoparticles in sandwiched CdSe/ZnSe/ZnO nanotube array photoanode to substantially enhance solar photoelectrochemical water splitting for hydrogen evolution

By integrating ZnSe passivation nanoparticles into a binary heterostructure via a facile consecutive ion-replacement reaction method, we demonstrate a solar-light-driven CdSe/ZnSe/ZnO sandwich nanotube array photoanode for hydrogen evolution via a photoelectrochemical cell. The constructed CdSe/ZnSe/ZnO sandwich nanotube array photoanode displays drastically boosted photoelectrochemical ability to generate hydrogen. The hydrogen production rate of the CdSe/ZnSe/ZnO sandwich nanotube array photoanode reaches up to 54.4 mu mol h(-1), which is around 5 and 6 times that of the ZnSe/ZnO and ZnO nanotube array photoanodes, respectively. Moreover, the photoconversion efficiency of the CdSe/ZnSe/ZnO sandwich nanotube array photoanode reaches up to 1.7 % at 0.5 V versus RHE, which is 34 and 24 times that of the ZnO and ZnSe/ZnO nanotube array photoanodes, respectively. The measurements of the electrochemical properties demonstrate that the drastically enhanced PEC water splitting for hydrogen evolution of the sandwiched CdSe/ZnSe/ZnO nanotube arrays is attributed to the efficient separation of the photogenerated charge carriers.

Automated summary

The integration of ZnSe passivation nanoparticles into a binary heterostructure resulted in a CdSe/ZnSe/ZnO sandwich nanotube array photoanode, which exhibited significantly enhanced photoelectrochemical ability for hydrogen generation. The efficient separation of photogenerated charge carriers contributed to the drastically improved PEC water splitting performance of the sandwiched CdSe/ZnSe/ZnO nanotube arrays.