CuWO ₄ Anchored Zr ₂ CT x MXene Heterostructure for Catalytic Rhodamine B Degradation and Antibacterial Activity

This study describes the fluorine-free synthesis of Zr2CTx MXene, selectively etched from the Zr2SnC MAX phase using in situ generated HF, which acts as an electron mediator to engineer an interracially coupled 2D/metal oxide CuWO4 photocatalyst. The triclinic CuWO4 nanocrystals are synthesised through a base-free precipitation method followed by hydrothermal treatment and are uniformly anchored onto MXene sheets sonochemically (ZCCTx), forming a robust heterointerface. The structures of all three materials are confirmed by XRD, FTIR, XPS, FESEM–EDAX, HRTEM, and SAED analysis, complemented by UV-DRS, TGA-DTA, DLS, and ζ potential measurements. The heterostructured ZCCT6 exhibits an enhanced surface area of 99.9 m2 g–1, an optimised pore structure, and an effective surface charge of −39.9 mV, thereby facilitating superior charge separation. A reduced band gap of 1.6 eV, revealed by DRS and the Tauc plot analysis, promotes improved visible-light harvesting, leading to the degradation of 5 ppm RhB (99.8%) over 60 min, which is 27 times higher than the self-photolysis (19.3%), whereas kinetic modelling supports pseudo-first-order behaviours. Radical scavenging experiments show that holes and electrons are the most active oxidative species (e– > h+ > •O2– > •OH), demonstrating endurance toward coexisting anions and significant antibacterial activity against E. coli DH5α, with the largest inhibition zone resulting from synergistic ROS activity and MXene-mediated membrane disruption. To assess practical applicability, similar experiments were conducted in real water matrices, demonstrating promising potential for sunlight and visible-light-driven wastewater purification and antibacterial water treatment.