Investigation of Synergistically Developed p-Co3O4/n-ZnHoCuO based Junction for Enhanced Photocatalytic, Electrocatalytic, and Energy Storage Applications

Muhammad Shahid Nadeem; Baoji Miao; Aqsa Naz; Muhammad Salman; Jinbo Bai; Mohammed A Al-Tahan; Ahmed Althobaiti; Alsharef Mohammad; Muhammad Yasir; Farooq Ahmad; Tauseef Munawar; Abdul Shakoor; Faisal Iqbal

doi:10.1016/j.jcis.2025.138045

Investigation of Synergistically Developed p-Co₃O₄/n-ZnHoCuO based Junction for Enhanced Photocatalytic, Electrocatalytic, and Energy Storage Applications

J Colloid Interface Sci. 2025 Jun 10;699(Pt 1):138045. doi: 10.1016/j.jcis.2025.138045. Online ahead of print.

Authors

Affiliations

¹ Henan International Joint Laboratory of Nano-Photoelectric Magnetic Material, Zhengzhou 450001, Henan, PR China. Electronic address: shahidnadeem2016@gmail.com.
² Henan International Joint Laboratory of Nano-Photoelectric Magnetic Material, Zhengzhou 450001, Henan, PR China. Electronic address: mbjhaut@163.com.
³ Institute of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan. Electronic address: aqsanaz9442@gmail.com.
⁴ Henan International Joint Laboratory of Nano-Photoelectric Magnetic Material, Zhengzhou 450001, Henan, PR China.
⁵ Univ Paris Saclay, Centrale Supelec, ENS Paris Saclay, LMPS, F-91190 Gif Sur Yvette, France.
⁶ Chemistry Department, Faculty of Science, Al-Azhar University, Assiut 71524, Egypt.
⁷ Electrical Engineering Department, Taif University, Saudia Arabia.
⁸ Department of Materials Science & Engineering, Institute of Space Technology, Islamabad, Pakistan.
⁹ Centre of Excellence in Solid State Physics University of the Punjab Lahore, Pakistan.
¹⁰ Guangzhou Institute of Energy Conversion, Chinese Academic of Sciences, No. 2 Nengyuan Road, Wushan, Tianhe District, Guangzhou 510640, China.
¹¹ Institute of Physics, The Islamia University of Bahawalpur, 63100, Pakistan. Electronic address: faisal.iqbal@iub.edu.pk.

PMID: 40527140
DOI: 10.1016/j.jcis.2025.138045

Abstract

In this work, we have reported p-Co₃O₄/n-ZnHoCuO junction growth via a cost-effective and straightforward co-precipitation synthesis route for the first time. The structural study was investigated by employing XRD and FTIR spectroscopy. An optical study was carried out by UV-visible spectroscopy. Whereas the surface morphology and elemental analysis were analyzed using SEM and EDX. TEM analysis was included to explore the internal texture of the p-n junction. In the meantime, the XPS demonstrated that Cu, Ho-doping in ZnO and coupling with Co₃O₄ resulted in the production of lattice defects and oxygen vacancies in ZnO, along with different oxidation states of Ho, Cu, Zn, Co, and O. In this context, the photocatalytic activity was investigated with the help of two different dyes, such as MB and MO dyes, under sunlight irradiation. As-synthesized material, when employed to fabricate the electrode material and assess its potential for supercapacitor applications, demonstrated an outstanding specific capacity of 1812.90 C/g at 7.5 A/g, as measured via GCD testing, highlighting its potential for supercapacitor applications. Additionally, it demonstrated a satisfactory electrochemical and electrocatalytic properties for the as-fabricated junction, OER activity and energy storage capabilities of such materials have been confirmed by coupling contact. The calculated Tafel slope was 43.14 mV dec^-1 shown by the p-n junction catalyst's redox activity. At a current density of 10 mA cm^-2, the developed electrocatalyst had a low overpotential of 115 mV. The effects of Cu, Ho-doping on ZnO and the coupling of Co₃O₄ support emphasize the exceptional benefits of electrochemical performance and enhance its potential for use in effective photocatalysis, electrolysis, and energy storage technologies.

Keywords: Energy storage; OER; P-n junction; Photocatalysis; TEM; UV–vis; XPS; XRD.