Interfacial charge kinetics of ZnO/ZnTe heterostructured nanorod arrays for CO2 photoreduction. (10th May 2018)

• Record Type: Journal Article
• Authors: Iqbal, Muzaffar; Wang, Yanjie; Hu, Haifeng; He, Meng; Shah, Aamir Hassan; Li, Pan; Lin, Lin; Woldu, Abebe Reda; He, Tao
• Is Part Of: Electrochimica acta. Volume 272(2018)
• Page Start: 203
• Page End: 211
• Publication Date: 2018-05-10
• Subjects: ZnO/ZnTe -- Kinetics of photoinduced charge carriers -- Mott-Schottky analysis -- Photoelectrochemical performance -- CO2 reduction; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.03.171
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Constructing p-n heterojunction system is promising in achieving high performance materials for photocatalysis application. Studying the charge dynamics across the interface is instructive in interpreting the performance and providing approaches for further improvement. ZnO/ZnTe heterostructured nanorod arrays for CO2 photoreduction are prepared via a simple electrochemical deposition approach. X-ray diffraction and transmission electron microscopy confirm successful construction of the ZnO/ZnTe heterojunction. The charge dynamics are studied by various photoelectrochemical (PEC) characterizations, the results of which indicate that the deposition of ZnTe is in favor of the charge kinetics like generation and transfer, and the PEC performance increases with the raise of the ZnTe amount. Mott-Schottky plots are employed to probe the mechanism of the PEC performance, based on which the interfacial space charge region is thoroughly discussed too. An electronic band structure model of the ZnO/ZnTe heterostructure electrode in the aqueous solution is thus put forward, which may promote the understanding of the relevant charge transfer. Finally, the ZnO/ZnTe heterostructure is applied for photocatalytic reduction of CO2, and the 8 h-CH4 yield can reach 0.04 μmol/cm 2 for ZnO/ZnTe prepared with deposition time of 3 min for ZnTe. Graphical abstract: Highlights: ZnO nanorod/ZnTe heterostructure was prepared by electrochemical deposition. Charge generation, separation and transfer are thoroughly studied electrochemically. ZnO/ZnTe heterostructure displays superior photoelectrochemical property to ZnO. Mott-Schottky analysis can reveal the electronic band structure of obtained ZnO/ZnTe. ZnO/ZnTe-3min can photoreduce CO2 into CH4 with 8-h yield of 0.04 μmol/cm 2 .