Bi-metallic phosphate: Active and stable bifunctional electrocatalysts for alkaline overall water splitting

Rehan Ali Qureshi; Azmat Ali; Muhammad Yameen Solangi; Muhammad Ali Shar; Abdulaziz Alhaza; Imtiaz Ali Soomro; Mehran Ali Qureshi; Mukesh Kumar; Hamza Majeed Ansari; Abdul Hanan; Umair Aftab

doi:10.1016/j.ijhydene.2025.150288

Bi-metallic phosphate: Active and stable bifunctional electrocatalysts for alkaline overall water splitting

Rehan Ali Qureshi
, Azmat Ali
, Muhammad Yameen Solangi
, Muhammad Ali Shar
, Abdulaziz Alhaza
, Imtiaz Ali Soomro
, Mehran Ali Qureshi
, Mukesh Kumar
, Hamza Majeed Ansari
, Abdul Hanan^*
, Umair Aftab^*

^*Corresponding author for this work

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

3 Scopus citations

Abstract

Hydrogen (H₂) energy is considered as promising energy with no emission of greenhouse gases. This energy can be produced economically and efficiently via electrochemical water splitting (EWS) technique among various other techniques. Herein, this study comprises the synthesis of various bi-metallic phosphates, particularly cobalt phosphate, cobalt nickel phosphate, cobalt copper phosphate, and cobalt iron phosphate (CIP) through aqueous chemical growth method. As-synthesized bi-metallic phosphates have been explored for physical characterization through X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) to evaluate their crystallinity, morphology, composition, and surface functionality features. The electrochemical investigation is also carried out to determine bifunctional electrochemical performance of prepared electrocatalysts. Wherein, CIP was found as an optimized electrocatalyst for bi-functional activity towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Interestingly, the CIP catalyst exhibits the lowest overpotential of 325 mV for HER and 300 mV for OER at 10 mA cm⁻² current density in 1.0 M potassium hydroxide (KOH) media. The optimized catalyst offers a fast rate of reaction kinetics by revealing lower Tafel slope values i.e., 53.6 and 58.4 mV.dec⁻¹, respectively. In addition, it is stable and durable up to 40–45 h for HER and OER activity. The CIP has also enhanced intrinsic behavior validated from higher Turnover frequency (TOF) values and normalized data. Moreover, high theoretical H₂ and O₂ production rate obtained as 470.6 × 10⁻⁶ and 44.5 × 10⁻⁶ mol s⁻¹ cm⁻¹ due to large electrochemical active surface area (ECSA) of 342.5 cm². This novel bi-metallic (Co -Fe) phosphate-based electrocatalyst can be a replaceable materials for the PGM metal based electrocatalysts practically.

Original language	English
Article number	150288
Journal	International Journal of Hydrogen Energy
Volume	155
DOIs	https://doi.org/10.1016/j.ijhydene.2025.150288
State	Published - 6 Aug 2025
Externally published	Yes

Bibliographical note

Publisher Copyright:
© 2025 Hydrogen Energy Publications LLC

Keywords

Bi-metallic phosphates
Bifunctional catalyst
Electrochemical water splitting
Hydrogen evolution reaction
Oxygen evolution reaction

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment
Fuel Technology
Condensed Matter Physics
Energy Engineering and Power Technology

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.ijhydene.2025.150288

Cite this

Qureshi, R. A., Ali, A., Solangi, M. Y., Shar, M. A., Alhaza, A., Soomro, I. A., Qureshi, M. A., Kumar, M., Ansari, H. M., Hanan, A., & Aftab, U. (2025). Bi-metallic phosphate: Active and stable bifunctional electrocatalysts for alkaline overall water splitting. International Journal of Hydrogen Energy, 155, Article 150288. https://doi.org/10.1016/j.ijhydene.2025.150288

@article{d90c24533d0b459aafacf4282019455b,

title = "Bi-metallic phosphate: Active and stable bifunctional electrocatalysts for alkaline overall water splitting",

abstract = "Hydrogen (H2) energy is considered as promising energy with no emission of greenhouse gases. This energy can be produced economically and efficiently via electrochemical water splitting (EWS) technique among various other techniques. Herein, this study comprises the synthesis of various bi-metallic phosphates, particularly cobalt phosphate, cobalt nickel phosphate, cobalt copper phosphate, and cobalt iron phosphate (CIP) through aqueous chemical growth method. As-synthesized bi-metallic phosphates have been explored for physical characterization through X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) to evaluate their crystallinity, morphology, composition, and surface functionality features. The electrochemical investigation is also carried out to determine bifunctional electrochemical performance of prepared electrocatalysts. Wherein, CIP was found as an optimized electrocatalyst for bi-functional activity towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Interestingly, the CIP catalyst exhibits the lowest overpotential of 325 mV for HER and 300 mV for OER at 10 mA cm−2 current density in 1.0 M potassium hydroxide (KOH) media. The optimized catalyst offers a fast rate of reaction kinetics by revealing lower Tafel slope values i.e., 53.6 and 58.4 mV.dec−1, respectively. In addition, it is stable and durable up to 40–45 h for HER and OER activity. The CIP has also enhanced intrinsic behavior validated from higher Turnover frequency (TOF) values and normalized data. Moreover, high theoretical H2 and O2 production rate obtained as 470.6 × 10−6 and 44.5 × 10−6 mol s−1 cm−1 due to large electrochemical active surface area (ECSA) of 342.5 cm2. This novel bi-metallic (Co -Fe) phosphate-based electrocatalyst can be a replaceable materials for the PGM metal based electrocatalysts practically.",

keywords = "Bi-metallic phosphates, Bifunctional catalyst, Electrochemical water splitting, Hydrogen evolution reaction, Oxygen evolution reaction",

author = "Qureshi, \{Rehan Ali\} and Azmat Ali and Solangi, \{Muhammad Yameen\} and Shar, \{Muhammad Ali\} and Abdulaziz Alhaza and Soomro, \{Imtiaz Ali\} and Qureshi, \{Mehran Ali\} and Mukesh Kumar and Ansari, \{Hamza Majeed\} and Abdul Hanan and Umair Aftab",

note = "Publisher Copyright: {\textcopyright} 2025 Hydrogen Energy Publications LLC",

year = "2025",

month = aug,

day = "6",

doi = "10.1016/j.ijhydene.2025.150288",

language = "English",

volume = "155",

journal = "International Journal of Hydrogen Energy",

issn = "0360-3199",

publisher = "Elsevier Ltd.",

}

TY - JOUR

T1 - Bi-metallic phosphate

T2 - Active and stable bifunctional electrocatalysts for alkaline overall water splitting

AU - Qureshi, Rehan Ali

AU - Ali, Azmat

AU - Solangi, Muhammad Yameen

AU - Shar, Muhammad Ali

AU - Alhaza, Abdulaziz

AU - Soomro, Imtiaz Ali

AU - Qureshi, Mehran Ali

AU - Kumar, Mukesh

AU - Ansari, Hamza Majeed

AU - Hanan, Abdul

AU - Aftab, Umair

PY - 2025/8/6

Y1 - 2025/8/6

N2 - Hydrogen (H2) energy is considered as promising energy with no emission of greenhouse gases. This energy can be produced economically and efficiently via electrochemical water splitting (EWS) technique among various other techniques. Herein, this study comprises the synthesis of various bi-metallic phosphates, particularly cobalt phosphate, cobalt nickel phosphate, cobalt copper phosphate, and cobalt iron phosphate (CIP) through aqueous chemical growth method. As-synthesized bi-metallic phosphates have been explored for physical characterization through X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) to evaluate their crystallinity, morphology, composition, and surface functionality features. The electrochemical investigation is also carried out to determine bifunctional electrochemical performance of prepared electrocatalysts. Wherein, CIP was found as an optimized electrocatalyst for bi-functional activity towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Interestingly, the CIP catalyst exhibits the lowest overpotential of 325 mV for HER and 300 mV for OER at 10 mA cm−2 current density in 1.0 M potassium hydroxide (KOH) media. The optimized catalyst offers a fast rate of reaction kinetics by revealing lower Tafel slope values i.e., 53.6 and 58.4 mV.dec−1, respectively. In addition, it is stable and durable up to 40–45 h for HER and OER activity. The CIP has also enhanced intrinsic behavior validated from higher Turnover frequency (TOF) values and normalized data. Moreover, high theoretical H2 and O2 production rate obtained as 470.6 × 10−6 and 44.5 × 10−6 mol s−1 cm−1 due to large electrochemical active surface area (ECSA) of 342.5 cm2. This novel bi-metallic (Co -Fe) phosphate-based electrocatalyst can be a replaceable materials for the PGM metal based electrocatalysts practically.

AB - Hydrogen (H2) energy is considered as promising energy with no emission of greenhouse gases. This energy can be produced economically and efficiently via electrochemical water splitting (EWS) technique among various other techniques. Herein, this study comprises the synthesis of various bi-metallic phosphates, particularly cobalt phosphate, cobalt nickel phosphate, cobalt copper phosphate, and cobalt iron phosphate (CIP) through aqueous chemical growth method. As-synthesized bi-metallic phosphates have been explored for physical characterization through X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) to evaluate their crystallinity, morphology, composition, and surface functionality features. The electrochemical investigation is also carried out to determine bifunctional electrochemical performance of prepared electrocatalysts. Wherein, CIP was found as an optimized electrocatalyst for bi-functional activity towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Interestingly, the CIP catalyst exhibits the lowest overpotential of 325 mV for HER and 300 mV for OER at 10 mA cm−2 current density in 1.0 M potassium hydroxide (KOH) media. The optimized catalyst offers a fast rate of reaction kinetics by revealing lower Tafel slope values i.e., 53.6 and 58.4 mV.dec−1, respectively. In addition, it is stable and durable up to 40–45 h for HER and OER activity. The CIP has also enhanced intrinsic behavior validated from higher Turnover frequency (TOF) values and normalized data. Moreover, high theoretical H2 and O2 production rate obtained as 470.6 × 10−6 and 44.5 × 10−6 mol s−1 cm−1 due to large electrochemical active surface area (ECSA) of 342.5 cm2. This novel bi-metallic (Co -Fe) phosphate-based electrocatalyst can be a replaceable materials for the PGM metal based electrocatalysts practically.

KW - Bi-metallic phosphates

KW - Bifunctional catalyst

KW - Electrochemical water splitting

KW - Hydrogen evolution reaction

KW - Oxygen evolution reaction

UR - https://www.scopus.com/pages/publications/105010118365

U2 - 10.1016/j.ijhydene.2025.150288

DO - 10.1016/j.ijhydene.2025.150288

M3 - Article

AN - SCOPUS:105010118365

SN - 0360-3199

VL - 155

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

M1 - 150288

ER -

Bi-metallic phosphate: Active and stable bifunctional electrocatalysts for alkaline overall water splitting

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

UN SDGs

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