OICC Press Journal of Nanostructure in Chemistry 2193-8865 16 6 2026 08 25 Interfacial Engineering of Z-Scheme WC-WO3/BiOCl Heterojunction: A Dual-Function for Energy Storage and Environmental Applications 10.57647/jnsc.2026.1606.28 EN Maria Murtaza Department of Physics, International Islamic University, H-10 Islamabad, Pakistan Shamaila Sajjad Center for Interdisciplinary Research of Basic Science, International Islamic University, H-10 Islamabad, Pakistan https://orcid.org/0000-0002-8739-3788 Rehana Riaz Department of Physics, International Islamic University, H-10 Islamabad, Pakistan Tayyaba Taufiq Center for Interdisciplinary Research of Basic Science, International Islamic University, H-10 Islamabad, Pakistan Tahira Bano Department of Physics, International Islamic University, H-10 Islamabad, Pakistan Meer Dawood Khan Leghari Swinburne University of Technology, Australia Nilem Khaliq Department of Physics, University of Lakki Marwat, 28420, KPK, Pakistan Journal Article 2026 08 25 The WC–WO₃/BiOCl heterojunction was rationally engineered to enhance photocatalytic and electrochemical performance for environmental and energy-related applications. Although BiOCl possesses strong oxidative capability, its practical use is limited by poor conductivity and rapid charge recombination. To overcome these limitations, WC–WO₃/BiOCl system was constructed via a scalable route where partial carburization of WO₃ generated a conductive WC–WO₃ hybrid subsequently integrated with BiOCl nanosheets. The introduction of metallic WC establishes an electron-mediated Z-scheme pathway enabling efficient charge separation while preserving strong redox potentials. Structural and spectroscopic analyses confirmed successful formation of a tightly coupled heterojunction with modulated electronic structure. The reduced bandgap (3.40–2.53 eV) extends visible-light absorption while suppressed photoluminescence indicates enhanced carrier separation. The optimized 4.0 wt.% WC–WO₃/BiOCl sample achieved 95% degradation of Rhodamine B under visible light following pseudo-first-order kinetics. In addition, electrochemical measurements revealed a high specific capacity of 704 C g⁻¹ at 0.5 A g⁻¹ and an energy density of 70 Wh kg⁻¹ attributed to synergistic interactions and improved charge transport. This work provides a scalable and mechanism-oriented strategy for designing multifunctional heterostructures for photocatalysis and energy storage.