Acceptor-Doping Accelerated Charge Separation in Cu2 O Photocathode for Photoelectrochemical Water Splitting: Theoretical and Experimental Studies

Mengmeng Zhang; Jiajun Wang; Hui Xue; Jinfeng Zhang; Shengjie Peng; Xiaopeng Han; Yida Deng; Wenbin Hu

doi:10.1002/anie.202007680

Acceptor-Doping Accelerated Charge Separation in Cu₂ O Photocathode for Photoelectrochemical Water Splitting: Theoretical and Experimental Studies

Angew Chem Int Ed Engl. 2020 Oct 12;59(42):18463-18467. doi: 10.1002/anie.202007680. Epub 2020 Jul 13.

Authors

Mengmeng Zhang¹, Jiajun Wang¹, Hui Xue², Jinfeng Zhang¹, Shengjie Peng³, Xiaopeng Han¹, Yida Deng¹, Wenbin Hu^{1

4}

Affiliations

¹ School of Materials Science and Engineering, Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin, 300072, P. R. China.
² State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing, 100083, China.
³ Jiangsu Key Laboratory of Electrochemical Energy-Storage Technologies, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
⁴ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, P. R. China.

PMID: 32533640
DOI: 10.1002/anie.202007680

Abstract

Cu₂ O is a typical photoelectrocatalyst for sustainable hydrogen production, while the fast charge recombination hinders its further development. Herein, Ni²⁺ cations have been doped into a Cu₂ O lattice (named as Ni-Cu₂ O) by a simple hydrothermal method and act as electron traps. Theoretical results predict that the Ni dopants produce an acceptor impurity level and lower the energy barrier of hydrogen evolution. Photoelectrochemical (PEC) measurements demonstrate that Ni-Cu₂ O exhibits a photocurrent density of 0.83 mA cm^-2 , which is 1.34 times higher than that of Cu₂ O. And the photostability has been enhanced by 7.81 times. Moreover, characterizations confirm the enhanced light-harvesting, facilitated charge separation and transfer, prolonged charge lifetime, and increased carrier concentration of Ni-Cu₂ O. This work provides deep insight into how acceptor-doping modifies the electronic structure and optimizes the PEC process.

Keywords: charge transfer; copper; doping; kinetics; water splitting.

Abstract

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