Conductivity controlling of Cu2O film photoelectrode for water splitting by a novel electrochemical approach - Differential potentiostatic deposition. (11th January 2021)

• Record Type: Journal Article
• Authors: Qi, Gaowang; Liu, Meng; Tang, Changwei; Chang, Jing; Yang, Chongrong; Liu, Fujia; Ning, Xiaohui; Yang, Ying
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 3(2021)
• Page Start: 2878
• Page End: 2889
• Publication Date: 2021-01-11
• Subjects: Cuprous oxide (Cu2O) -- Electrochemical deposition -- Semiconductor films -- Photoelectrode -- Photoelectrochemical cell -- Water splitting; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.04.176
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Cuprous oxide (Cu2 O) is a kind of low-cost and promising material for water splitting to produce hydrogen ( p -type Cu2 O) and oxygen ( n -type Cu2 O). However, the reason of conductivity transforming from p -type to n -type for Cu2 O films during potentiostatic deposition is waiting to be revealed. In this work, a novel electrochemical technology, differential potentiostatic deposition (DPD), is developed by coupling a 3-electrode setup with a resistor connected in series with the counter electrode circuit through a potentiostat. By this approach, deposition current density is adjusted in a short period to simulate different stages in a traditional potentiostatic deposition (TPD). The result shows that semiconducting conductivity of Cu2 O film changes from p -type to n -type with time during a long-term TPD in basic CuSO4 solution. Employing the DPD method, conductivity of Cu2 O film transforms from p -type to n -type with current density decreasing. Through characterizing thickness, composition and photoelectrochemical performance of Cu2 O films, the mechanism of semiconducting conductivity transformation for Cu2 O films is proposed. Besides, the results indicate that the DPD is an effective method to tune the conductivity of metal oxide photoelectrodes for water splitting. Graphical abstract: Image 1 Highlights: Differential potentiostatic deposition (DPD) was developed. Mechanism of tuning Cu2 O conductivity was shed light on. DPD divided and reproduced traditional potentiostatic deposition (TPD) process. Cu2 O photoelectrode with carrier gradient was made by long-term TPD.