Stable core/shell CdTe/Mn-CdS quantum dots sensitized three-dimensional, macroporous ZnO nanosheet photoelectrode and their photoelectrochemical properties.

A novel photoelectrode based on ZnS/CdTe/Mn-CdS/ZnS-sensitized three-dimensional macroporous ZnO nanosheet (NS) has been prepared by electrodeposition and successive ion layer adsorption and reaction (SILAR) method. The photoelectrode performances were significantly improved through the coupling of the core/shell CdTe/Mn-CdS quantum dots (QDs) with ZnO NS, and the introduction of the ZnS layer as a potential barrier. The photocurrent density systematically increases from ZnO NS (0.45 mA/cm2), CdTe/Mn-CdS/ZnO NS (4.98 mA/cm2), to ZnS/CdTe/Mn-CdS/ZnS/ZnO (6.23 mA/cm2) under the irradiation of AM 1.5G simulated sunlight. More important, the ZnS/CdTe/Mn-CdS/ZnS-sensitized ZnO NS photoelectrode provides a remarkable photoelectrochemical cell efficiency of 4.20% at −0.39 V vs Ag/AgCl.