1. Cooperative catalysis of Zn3(VO4)2/Ni(OH)2/rGO nanosheet arrays advancing highly active O2 reduction and water-splitting.
- Author
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Li, Xue, Gao, Xinglong, Guo, Enyan, Wei, Mingzhi, Si, Conghui, Lu, Qifang, and Pang, Yingping
- Subjects
OXYGEN evolution reactions ,ORBITAL hybridization ,HYDROGEN evolution reactions ,ELECTRON transport ,ELECTROCATALYSIS ,CHARGE exchange ,ELECTROCATALYSTS ,OXYGEN reduction - Abstract
Electrocatalytic O
2 conversion and water-splitting hold great promise to enable the chemicals–electricity inter-transition in many renewable-energy initiatives. Enhancing the kinetics of the oxygen reduction reaction (ORR) is challenging. Here, we present that Zn3 (VO4 )2 /Ni(OH)2 /rGO (reduced graphene oxide) nanosheet arrays-a Zn3 (VO4 )2 /Ni(OH)2 composite in the form of nanometre-thick nanosheets on an rGO substrate-serve as an efficient and stable electrocatalyst for the ORR in alkaline electrolytes. The thin-sheet structure and smaller free energy of Zn3 (VO4 )2 /Ni(OH)2 , as well as the excellent conductivity of the rGO substrate, enable a large electrochemically-active surface area and a high electron transport, contributing to the superior electrocatalytic oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). Furthermore, Zn3 (VO4 )2 /Ni(OH)2 /rGO and Zn3 (VO4 )2 /Ni(OH)2 samples exhibit remarkable long-term water-splitting stability of 48 h. Density functional theory (DFT) calculations reveal the optimized intermediate affinity ability at the Ni(OH)2 side, due to electrons transferring from Ni(OH)2 to Zn3 (VO4 )2 . Additionally, the higher hybridization degree of density of states (DOS) boosts electron transfer in the electrocatalytic process. More broadly, this work provides new inspiration for the construction of a novel noble metal-free electrocatalyst that could show great promise in energy electrocatalysis. [ABSTRACT FROM AUTHOR]- Published
- 2023
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