Enhanced visible-light-driven heterogeneous photocatalytic CO2 methanation using a Cu2O@Cu-MOF-74 thin film
Hao Wu,
Wahyu Prasetyo Utomo,
Yuanmeng Tian,
Chun Hong Mak,
Hoi Ying Chung,
Hsien-Yi Hsu,
Jin Shang,
Yun Hau Ng
Affiliations
Hao Wu
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China; Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China
Wahyu Prasetyo Utomo
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China
Yuanmeng Tian
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China; Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China
Chun Hong Mak
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China
Hoi Ying Chung
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China
Hsien-Yi Hsu
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China
Jin Shang
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China; Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China
Yun Hau Ng
School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, China; Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China; Corresponding author.
Cuprous oxide is a potential photocatalyst for the reduction of CO2. However, its high rate of charge recombination and low ability to adsorb CO2 limit its activity, particularly when gaseous CO2 was used. Herein, a Cu-based metal-organic framework (Cu-MOF-74) with high CO2 adsorption is coated onto Cu2O nanowires by a topotactic transformation method. The optimized Cu2O@Cu-MOF-74 composite thin film showed a CH4 evolution rate 4.5 times higher than that of bare Cu2O under visible light illumination (>420 nm), with water vapor as the electron donor. Analysis results of electrochemical impedance spectroscopy, transient photocurrent measurements, and fluorescence spectroscopy collectively suggest that the decoration of Cu2O with Cu-MOF-74 facilitates electron extraction from excited Cu2O, thereby inducing long-lived photocharges for the reduction of CO2. This study provides insights into the modification of transition metal oxides for application in photocatalysis by coating the surface with metal-organic frameworks.
