Engineering Ti₃C₂T_x MXene enhanced P/N-rich Zr coordination polymers for synergistic photocatalytic hydrogen production

The growing global energy crisis and rising environmental concerns urgently call for sustainable and clean energy solutions. Photocatalytic hydrogen production using sunlight and water is a highly promising method to address these issues. Despite notable progress, the lack of stable, visible-light-responsive, and high-surface-area photocatalysts is a key limitation. To tackle these limitations, current research focuses on designing and creating new Zr-based coordination polymer/MXene composites as advanced photocatalyst candidates. A six-armed hexatopic ligand enriched with phosphorus and nitrogen was synthesized to construct a Zr-based coordination polymer, which was grown directly onto varying amounts of Ti₃C₂Tₓ MXene layers, which function as a crucial co-catalyst via a solvothermal method. The characterizations of the produced composite materials were carried out using PXRD, FTIR, SEM, TEM, and XPS techniques, and their structural and morphological properties were thoroughly analyzed. Under simulated sunlight, the composite with 5 mg of MXene showed an exceptional hydrogen evolution rate of 10,149 μmol h⁻¹ g⁻¹, which is 3.3 times higher than that of the bare Zr coordination polymer and 7.5 times better than comparable studies reported in the literature. This notable boost in catalytic activity is attributed to the innovative combination of a phosphorus- and nitrogen-rich flexible zirconium coordination polymer with the MXene co-catalyst, which enhances the synergistic effect, electron migration, and transfer within the photocatalytic system. Based on the band structure and photoelectrochemical analysis, an S-scheme charge transfer mechanism was proposed for the photocatalytic process. This work offers a promising example for designing and improving coordination polymer/MXene photocatalysts and making a meaningful contribution toward satisfying the rising H₂ demand for a sustainable energy future.