Significant carrier recombination has severely limited the development of the most potential photoelectrocatalytic CO 2 reduction reaction (PEC-CO 2 RR). Herein, coral-like CuBi 2 O 4 -Bi 2 O 3 photocathodes are prepared using the strategy of the construction of heterojunction to improve the efficiency of carrier separation. As expected, its faradic efficiency of CO (FE CO ) at the lower potential (0.1 V vs. RHE) is 86.03 %, which is about 1.49 times higher than that of the original CuBi 2 O 4 film. The increased catalytic activity of CuBi 2 O 4 -Bi 2 O 3 can be attributed to the high surface area of the distinctive coral-like structure of Bi 2 O 3 , which enhances light absorption efficiency. Additionally, the higher degree of band bending in CuBi 2 O 4 -Bi 2 O 3 and the built-in electric field can speed up the transport rate of electrons, slow down the recombination of photogenerated electrons with holes and extend the lifetime of photogenerated electrons, allowing electrons to continuously participate in the reaction. This study proposes a novel strategy to optimize the efficiency of photoelectrocatalytic CO 2 reduction by CuBi 2 O 4 -based photocathodes.
Wenxiao Zhang,Zize Zhao,Ziyang Zhu,Li Zhang,Xiaohui Xu,Xuemei Chen,Xinyan Wang,Min Lu
The rapid development of high-performance electrode materials for asymmetric supercapacitors (ASCs) needs to solve the bottleneck problem of low energy density. Compared with the positive electrode material, the development of the negative electrode material is relatively lagging and has become one of the key "short board" to limit the energy density of the supercapacitor device. In this study, the oxygen vacancy-rich CuBi 2 O 4 nanoparticles are triumphantly anchored on the interface of rod-like Bi 2 O 3 after calcination to prepare the heterostructure CuBi 2 O 4 /Bi 2 O 3 (CBO/BO) composites by the combination of simple hydrothermal process and calcination. Due to the unique anchoring mode, heterogeneous structure, and oxygen vacancy introduction, the CBO/BO as the cathode processes the capacitance of 294.7 mAh g −1 at 1 A g −1 . In addition, bimetallic NiCo layered double hydroxides (NCL) with the 3D flower-like structure prepared by a one-pot process is used as the positive electrode and the specific capacitance of 186.7 mAh g −1 at 1 A g −1 . The assembled water-based NCL//CBO/BO ASC triumphantly amplifies the potential window to 1.7 V, achieves the ultrahigh energy density between 91.8 and 52.9 Wh kg −1 at 850–8500 W kg −1 , and maintains the remarkable cycle consistency. Density functional theory calculation fully proves that oxygen vacancy and copper doping can significantly improve the electrochemical performance of electrode materials. Therefore, the research results in this paper afforded a feasible way to further develop asymmetric supercapacitors with ultrahigh energy density.
危险品化学品经营许可证（带存储）