Thermally reduced rGO-wrapped CoP/Co2P hybrid microflower as an electrocatalyst for hydrogen evolution reaction

Taek Seung Kim; Hee Jo Song; Mushtaq Ahmad Dar; Hyun Woo Shim; Dong Wan Kim

doi:10.1111/jace.15581

Thermally reduced rGO-wrapped CoP/Co₂P hybrid microflower as an electrocatalyst for hydrogen evolution reaction

Taek Seung Kim, Hee Jo Song, Mushtaq Ahmad Dar, Hyun Woo Shim, Dong Wan Kim

School of Civil, Environmental and Architectural Engineering

Research output: Contribution to journal › Article › peer-review

23 Citations (Scopus)

Abstract

Cobalt phosphides (CoP_x) are potential candidates for use as high-efficiency hydrogen evolution reaction electrocatalysts that can replace noble metals, such as Pt. Typically, CoP_x can be synthesized by phosphidation with Co-based precursors such as oxides or hydroxides. In this study, we propose a new strategy for synthesizing CoP_x through the thermal reduction in cobalt phosphate (Co₃(PO₄)₂). A reduced graphene oxide-wrapped CoP/Co₂P hybrid microflower was successfully synthesized by a facile coprecipitation method in a Co₃(PO₄)₂ matrix, followed by a thermal reduction process. Co₃(PO₄)₂ can be transformed to CoP/Co₂P by treatment at 700°C for 1 hour, maintaining the original particle morphology with the assistance of reduced graphene oxide (rGO). In a 0.5 mol/L H₂SO₄ solution, the rGO-CoP/Co₂P microflower catalyzes the hydrogen evolution reaction with an overpotential of 156 mV at a current density of 10 mA cm⁻², a Tafel slope of 53.8 mV dec⁻¹, and good stability as observed through long-term CV and chronoamperometry tests.

Original language	English
Pages (from-to)	3749-3754
Number of pages	6
Journal	Journal of the American Ceramic Society
Volume	101
Issue number	9
DOIs	https://doi.org/10.1111/jace.15581
Publication status	Published - 2018 Sep

Keywords

catalysts/catalysis
cobalt/cobalt compounds
graphene oxide
hydrogen evolution reaction
phosphates

ASJC Scopus subject areas

Ceramics and Composites
Materials Chemistry

Access to Document

10.1111/jace.15581

Cite this

@article{d06aa5b722164fc2951057f3fd5663e9,

title = "Thermally reduced rGO-wrapped CoP/Co2P hybrid microflower as an electrocatalyst for hydrogen evolution reaction",

abstract = "Cobalt phosphides (CoPx) are potential candidates for use as high-efficiency hydrogen evolution reaction electrocatalysts that can replace noble metals, such as Pt. Typically, CoPx can be synthesized by phosphidation with Co-based precursors such as oxides or hydroxides. In this study, we propose a new strategy for synthesizing CoPx through the thermal reduction in cobalt phosphate (Co3(PO4)2). A reduced graphene oxide-wrapped CoP/Co2P hybrid microflower was successfully synthesized by a facile coprecipitation method in a Co3(PO4)2 matrix, followed by a thermal reduction process. Co3(PO4)2 can be transformed to CoP/Co2P by treatment at 700°C for 1 hour, maintaining the original particle morphology with the assistance of reduced graphene oxide (rGO). In a 0.5 mol/L H2SO4 solution, the rGO-CoP/Co2P microflower catalyzes the hydrogen evolution reaction with an overpotential of 156 mV at a current density of 10 mA cm−2, a Tafel slope of 53.8 mV dec−1, and good stability as observed through long-term CV and chronoamperometry tests.",

keywords = "catalysts/catalysis, cobalt/cobalt compounds, graphene oxide, hydrogen evolution reaction, phosphates",

author = "Kim, {Taek Seung} and Song, {Hee Jo} and Dar, {Mushtaq Ahmad} and Shim, {Hyun Woo} and Kim, {Dong Wan}",

note = "Funding Information: National Research Foundation of Korea (NRF), Grant/Award Number: NRF- 2016M3A7B4909318; Ministry of Science, ICT, and Future Planning, South Korea; Korea Institute of Science and Technology, South Korea, Grant/Award Number: 2E26081-16-054; the Ministry of Environment, South Korea, Grant/Award Number: R2-17_2016002250005; ISPP at King Saud University, Grant/Award Number: ISPP# 0076 Funding Information: This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Ministry of Science, ICT, and Future Planning, South Korea (NRF-2016M3A7B4909318), by the institutional research program of the Korea Institute of Science and Technology, South Korea (2E26081-16-054), and by the R&D Center for Valuable Recycling(Global-Top R&BD Program) of the Ministry of Environment, South Korea (Project No.: R2-17_2016002250005). The authors extend their appreciation to the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP# 0076). Publisher Copyright: {\textcopyright} 2018 The American Ceramic Society",

year = "2018",

month = sep,

doi = "10.1111/jace.15581",

language = "English",

volume = "101",

pages = "3749--3754",

journal = "Journal of the American Ceramic Society",

issn = "0002-7820",

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T1 - Thermally reduced rGO-wrapped CoP/Co2P hybrid microflower as an electrocatalyst for hydrogen evolution reaction

AU - Kim, Taek Seung

AU - Song, Hee Jo

AU - Dar, Mushtaq Ahmad

AU - Shim, Hyun Woo

AU - Kim, Dong Wan

N1 - Funding Information: National Research Foundation of Korea (NRF), Grant/Award Number: NRF- 2016M3A7B4909318; Ministry of Science, ICT, and Future Planning, South Korea; Korea Institute of Science and Technology, South Korea, Grant/Award Number: 2E26081-16-054; the Ministry of Environment, South Korea, Grant/Award Number: R2-17_2016002250005; ISPP at King Saud University, Grant/Award Number: ISPP# 0076 Funding Information: This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Ministry of Science, ICT, and Future Planning, South Korea (NRF-2016M3A7B4909318), by the institutional research program of the Korea Institute of Science and Technology, South Korea (2E26081-16-054), and by the R&D Center for Valuable Recycling(Global-Top R&BD Program) of the Ministry of Environment, South Korea (Project No.: R2-17_2016002250005). The authors extend their appreciation to the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP# 0076). Publisher Copyright: © 2018 The American Ceramic Society

PY - 2018/9

Y1 - 2018/9

N2 - Cobalt phosphides (CoPx) are potential candidates for use as high-efficiency hydrogen evolution reaction electrocatalysts that can replace noble metals, such as Pt. Typically, CoPx can be synthesized by phosphidation with Co-based precursors such as oxides or hydroxides. In this study, we propose a new strategy for synthesizing CoPx through the thermal reduction in cobalt phosphate (Co3(PO4)2). A reduced graphene oxide-wrapped CoP/Co2P hybrid microflower was successfully synthesized by a facile coprecipitation method in a Co3(PO4)2 matrix, followed by a thermal reduction process. Co3(PO4)2 can be transformed to CoP/Co2P by treatment at 700°C for 1 hour, maintaining the original particle morphology with the assistance of reduced graphene oxide (rGO). In a 0.5 mol/L H2SO4 solution, the rGO-CoP/Co2P microflower catalyzes the hydrogen evolution reaction with an overpotential of 156 mV at a current density of 10 mA cm−2, a Tafel slope of 53.8 mV dec−1, and good stability as observed through long-term CV and chronoamperometry tests.

AB - Cobalt phosphides (CoPx) are potential candidates for use as high-efficiency hydrogen evolution reaction electrocatalysts that can replace noble metals, such as Pt. Typically, CoPx can be synthesized by phosphidation with Co-based precursors such as oxides or hydroxides. In this study, we propose a new strategy for synthesizing CoPx through the thermal reduction in cobalt phosphate (Co3(PO4)2). A reduced graphene oxide-wrapped CoP/Co2P hybrid microflower was successfully synthesized by a facile coprecipitation method in a Co3(PO4)2 matrix, followed by a thermal reduction process. Co3(PO4)2 can be transformed to CoP/Co2P by treatment at 700°C for 1 hour, maintaining the original particle morphology with the assistance of reduced graphene oxide (rGO). In a 0.5 mol/L H2SO4 solution, the rGO-CoP/Co2P microflower catalyzes the hydrogen evolution reaction with an overpotential of 156 mV at a current density of 10 mA cm−2, a Tafel slope of 53.8 mV dec−1, and good stability as observed through long-term CV and chronoamperometry tests.

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