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Title: High-Performance Overall Water Splitting Electrocatalysts Derived from Cobalt-Based Metal–Organic Frameworks

Abstract

The design of active, robust, and nonprecious electrocatalysts with both H 2 and O 2 evolution reaction (HER and OER) activities for overall water splitting is highly desirable but remains a grand challenge. Here in this article, we report a facile two-step method to synthesize porous Co-P/NC nanopolyhedrons composed of CoP x (a mixture of CoP and Co 2P) nanoparticles embedded in N-doped carbon matrices as electrocatalysts for overall water splitting. The Co-P/NC catalysts were prepared by direct carbonization of Co-based zeolitic imidazolate framework (ZIF-67) followed by phosphidation. Benefiting from the large specific surface area, controllable pore texture, and high nitrogen content of ZIF (a subclass of metal–organic frameworks), the optimal Co-P/NC showed high specific surface area of 183 m 2 g -1 and large mesopores, and exhibited remarkable catalytic performance for both HER and OER in 1.0 M KOH, affording a current density of 10 mA cm -2 at low overpotentials of -154 mV for HER and 319 mV for OER, respectively. Furthermore, a Co-P/NC-based alkaline electrolyzer approached 165 mA cm -2 at 2.0 V, superior to that of Pt/IrO 2 couple, along with strong stability. Various characterization techniques including X-ray absorption spectroscopy (XAS) revealed that the superior activitymore » and strong stability of Co-P/NC originated from its 3D interconnected mesoporosity with high specific surface area, high conductivity, and synergistic effect of CoP x encapsulated within N-doped carbon matrices.« less

Authors:
 [1];  [1];  [1];  [2];  [2];  [1]
  1. Utah State Univ., Logan, UT (United States). Dept. of Chemistry and Biochemistry
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Biophysics and Integrated Bioimaging Division
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Institutes of Health (NIH)
OSTI Identifier:
1379134
DOE Contract Number:  
AC02-05CH11231; P41GM103393
Resource Type:
Journal Article
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Volume: 27; Journal Issue: 22; Journal ID: ISSN 0897-4756
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

You, Bo, Jiang, Nan, Sheng, Meili, Gul, Sheraz, Yano, Junko, and Sun, Yujie. High-Performance Overall Water Splitting Electrocatalysts Derived from Cobalt-Based Metal–Organic Frameworks. United States: N. p., 2015. Web. doi:10.1021/acs.chemmater.5b02877.
You, Bo, Jiang, Nan, Sheng, Meili, Gul, Sheraz, Yano, Junko, & Sun, Yujie. High-Performance Overall Water Splitting Electrocatalysts Derived from Cobalt-Based Metal–Organic Frameworks. United States. https://doi.org/10.1021/acs.chemmater.5b02877
You, Bo, Jiang, Nan, Sheng, Meili, Gul, Sheraz, Yano, Junko, and Sun, Yujie. Thu . "High-Performance Overall Water Splitting Electrocatalysts Derived from Cobalt-Based Metal–Organic Frameworks". United States. https://doi.org/10.1021/acs.chemmater.5b02877.
@article{osti_1379134,
title = {High-Performance Overall Water Splitting Electrocatalysts Derived from Cobalt-Based Metal–Organic Frameworks},
author = {You, Bo and Jiang, Nan and Sheng, Meili and Gul, Sheraz and Yano, Junko and Sun, Yujie},
abstractNote = {The design of active, robust, and nonprecious electrocatalysts with both H2 and O2 evolution reaction (HER and OER) activities for overall water splitting is highly desirable but remains a grand challenge. Here in this article, we report a facile two-step method to synthesize porous Co-P/NC nanopolyhedrons composed of CoPx (a mixture of CoP and Co2P) nanoparticles embedded in N-doped carbon matrices as electrocatalysts for overall water splitting. The Co-P/NC catalysts were prepared by direct carbonization of Co-based zeolitic imidazolate framework (ZIF-67) followed by phosphidation. Benefiting from the large specific surface area, controllable pore texture, and high nitrogen content of ZIF (a subclass of metal–organic frameworks), the optimal Co-P/NC showed high specific surface area of 183 m2 g-1 and large mesopores, and exhibited remarkable catalytic performance for both HER and OER in 1.0 M KOH, affording a current density of 10 mA cm-2 at low overpotentials of -154 mV for HER and 319 mV for OER, respectively. Furthermore, a Co-P/NC-based alkaline electrolyzer approached 165 mA cm-2 at 2.0 V, superior to that of Pt/IrO2 couple, along with strong stability. Various characterization techniques including X-ray absorption spectroscopy (XAS) revealed that the superior activity and strong stability of Co-P/NC originated from its 3D interconnected mesoporosity with high specific surface area, high conductivity, and synergistic effect of CoPx encapsulated within N-doped carbon matrices.},
doi = {10.1021/acs.chemmater.5b02877},
url = {https://www.osti.gov/biblio/1379134}, journal = {Chemistry of Materials},
issn = {0897-4756},
number = 22,
volume = 27,
place = {United States},
year = {2015},
month = {11}
}