A photo rechargeable capacitor based on the p–n heterojunction of ZnO/ZIF-67 showing enhanced photovoltage
Yanlong Lv,
Xin Sun,
Changhua Mi,
Jianan Gu,
Yanhong Wang,
Meicheng Li
Affiliations
Yanlong Lv
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, 100096 Beijing, China
Xin Sun
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, 100096 Beijing, China
Changhua Mi
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, 100096 Beijing, China
Jianan Gu
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, 100096 Beijing, China
Yanhong Wang
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, 100096 Beijing, China
Meicheng Li
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, 100096 Beijing, China
The photo rechargeable device (PRD) has been continuously drawing attention because it combines energy conversion and storage in one device. As for the photoelectrode of PRD, the construction of heterojunction is of crucial importance to enhance the photo performance. In this work, a two-electrode photo rechargeable capacitor based on the p–n heterojunction of ZnO/ZIF-67 is fabricated. ZIF-67 not only serves as the energy storage material but also forms the p–n heterojunction together with ZnO. A fast volatilization method was adopted for the in situ growth of ZIF-67 on ZnO nanorods to ensure sufficient mass loading and fewer interface defects. The results show a photovoltage of 0.36 V (0.2 V higher than single ZnO), a specific capacitance of 759.0 mF/g, and an overall energy conversion efficiency of 0.49%. The enhanced photovoltage is attributed to the p–n heterojunction. Moreover, a practical button cell was also fabricated, with 91% Coulombic efficiency remaining after 3000 cycles in the dark.
