Pyro–photocatalytic synergy in BaTiO3/CuS composites for high-efficiency dye degradation

Abstract

BaTiO₃/CuS composites were synthesized via a hydrothermal route to exploit the synergistic coupling of pyroelectric polarization and photocatalysis for efficient dye degradation. The cubic BaTiO₃ nanoparticles, integrated with two-dimensional CuS nanosheets, form Schottky junctions that facilitate interfacial charge separation, as validated by density functional theory (DFT) calculations. Photocatalytic evaluation reveals that the optimal BaTiO₃/7.5%CuS composite achieves 93.9% RhB degradation within 60 min, outperforming pristine BaTiO₃ by 3.8-fold. Notably, introducing temperature fluctuation (25–60 °C, dT/dt = 7 °C min⁻¹) activates pyroelectric polarization in BaTiO₃, synergistically elevating the degradation rate constant to 0.120 min⁻¹—a 24.5-fold enhancement over conventional photocatalysis. This synergy stems from the pyroelectric field dynamically modulating the Schottky barrier height and simultaneously acting as directed electron transfer pathways to suppress the recombination of photogenerated charge carriers. Furthermore, the composite exhibits exceptional stability, maintaining 98.8% of its photocatalytic efficiency after nine cycles. By leveraging ambient thermal fluctuations and solar energy, this work introduces a dual-energy-driven strategy for environmental remediation, offering a sustainable and cost-effective solution for rapid organic pollutant removal.