• A direct-Z-scheme g-C3N4/Ti3C2/TiO2 heterojunction was synthesized via one-step aqueous sonication, achieving 99.2% degradation of Rhodamine B under optimal conditions.
• Ti3C2 acts as an electron bridge, facilitating efficient charge separation and transfer in the Z-scheme system.
• The composite exhibits enhanced photocatalytic stability and performance compared to pristine g-C3N4, attributed to the synergistic effects of the components.
• This work offers a simple, scalable method for designing high-performance photocatalysts for dye wastewater treatment.