@article{Zhang2021, 
author = {Zeyi Zhang and Yangyang Tan and Tang Zeng and Liyue Yu and Runzhe Chen and Niancai Cheng and Shichun Mu and Xueliang Sun},
title = {Tuning the dual-active sites of ZIF-67 derived porous nanomaterials for boosting oxygen catalysis and rechargeable Zn-air batteries},
year = {2021},
journal = {Nano Research},
volume = {14},
number = {7},
pages = {2353-2362},
keywords = {metal-organic frameworks, density functional theory (DFT), Zn-air batteries, dual-active sites, bifunctional oxygen electrocatalysts},
url = {https://www.sciopen.com/article/10.1007/s12274-020-3234-6},
doi = {10.1007/s12274-020-3234-6},
abstract = {The rational control of the active site of metal-organic frameworks (MOFs) derived nanomaterials is essential to build efficient bifunctional oxygen reduction/evolution reaction (ORR/OER) catalysts. Accordingly, through designing and constructing a Co3O4-Co heterostructure embedded in Co, N co-doped carbon polyhedra derived (Co3O4-Co@NC) from the in-situ compositions of ZIF-67 and cobalt nanocrystals synthesized by the strategy of in-situ NaBH4 reduction, the dual-active site (Co3O4-Co and Co-Nx) is synchronously realized in a MOFs derived nanomaterials. The formed Co3O4-Co@NC shows excellent bifunctional electrocatalytic activity with ultra-small potential gap (ΔE = Ej=10 (OER) - E1/2 (ORR)) of 0.72 V, which surpasses the commercial Pt/C and RuO2 catalysts. The theory calculation results reveal that the excellent bifunctional electrocatalytic activity can be attributed to the charge redistribution of Co of Co-Nx induced by the synergistic effects of well-tuned active sites of Co3O4-Co nanoparticle and Co-Nx, thus optimizing the rate-determining step of the desorption of O2* intermediate in ORR and OH* intermediate in OER. The rechargeable Zn-air batteries with our bifunctional catalysts exhibit superior performance as well as high cycling stability. This simple-effective optimization strategy offers prospects for tuning the active site of MOF derived bifunctional catalyst in electrochemical energy devices.}
}