Evaluation of a multi-dimensional hybrid photocatalyst for enrichment of H-2 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-C3N4 via a facile sonication approach. The hybrid ZNTCN exhibited a considerable enhancement of the photocatalytic H-2 evolution and degradation of methylene blue under visible-light irradiation. The rate of H2 evolution with the ZNTCN sample (295.88 mu mol g(-1)) was six-fold and three-fold higher than those of pure ZnTiO3 (56.72 mu mol g(-1)) and g-C3N4 (106.22 mu mol 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.