Evaluation of a multi-dimensional hybrid photocatalyst for enrichment of H2 evolution and elimination of dye/non-dye pollutants

Abstract

A unique ZnTiO₃/g-C₃N₄ (ZNTCN) heterogeneous photocatalyst was fabricated using an electrospinning method combined with a sonication process. Initially, 1-dimensional (1D) nanofibers of ZnTiO₃ (ca. 160 nm in diameter) were obtained by electrospinning and then combined with 2-dimensional (2D) nanosheets of g-C₃N₄via a facile sonication approach. The hybrid ZNTCN exhibited a considerable enhancement of the photocatalytic H₂ evolution and degradation of methylene blue under visible-light irradiation. The rate of H₂ evolution with the ZNTCN sample (295.88 μmol g⁻¹) was six-fold and three-fold higher than those of pure ZnTiO₃ (56.72 μmol g⁻¹) and g-C₃N₄ (106.22 μmol g⁻¹), respectively. In addition, the optimal ZNT : CN ratio (40 : 60 w/w) had shown excellent photodegradation performance towards removal of methylene blue, phenol, 4-chlorophenol, and 4-nitrophenol contaminants compared to those of bare ZnTiO₃ nanofibers and g-C₃N₄ sheets. Clearly, the g-C₃N₄ nanosheets interacted synergistically with the ZnTiO₃ nanofibers. The improvement in photocatalytic activity was mainly attributed to rapid charge transportation, increased optical absorbance and efficient separation of photoelectrons from the barrier potential produced at the interface. Moreover, dramatic suppression of recombination losses of the hybrid photocatalyst was confirmed through room-temperature photoluminescence, photocurrent response, and electrochemical impedance spectroscopy. These novel heterogeneous photocatalysts were shown to be very promising in green technology as well as for degradation of phenolic/non-phenolic pollutants.