New highly efficient 2D/1D HAp/g‒C3N4 photocatalyst thin film insight into crystal orientation and C‒vacancy effects. (September 2022)

• Record Type: Journal Article
• Authors: Zargazi, Mahboobeh; Chahkandi, Mohammad; Baghayeri, Mahdi
• Is Part Of: Chemosphere. Volume 303:Part 2(2022)
• Publication Date: 2022-09
• Subjects: Crystal facets of HAp nanoplates -- Urchin‒like g‒C3N4 nanotubes -- O‒vacancy of phosphate group -- Wrapped thin film -- Photocatalytic degradation of 4‒nitrophenol; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135079
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The novel synthetic Sol‒EPD process of a thin film including of well decorated g‒C3 N4 nanotubes on plate‒like hydroxyapatite (HAp) were applied. Using Sol‒EPD designable method anisotropic growth of HAp nanocrystals on the substrate were achieved. It has provided the orientation of the different crystal facets resulted in the photogenerated O‒vacancy from phosphate groups. Based on the studied XRD pattern, EPD deposited film of HAp was oriented along c ‒plane that can improve the photocatalytic activity of the designed composited film. Systematic designing was applied for decoration of g‒C3 N4 nanotubes on the HAp under thermal condensation of melamine coincide with calcination of HAp. This new designed HAp/g‒C3 N4 nanofilm was shown high photocatalytic efficiency and completely degradation of persistent pollutant of 4‒nitrophenol in the aqueous solution. According to the electrochemical impedance spectroscopy and current density studies, the higher charge separation/low charge recombination results were obtained for composited g‒C3 N4 /HAp nano‒film comparing with the single films of HAp and urchin like g‒C3 N4 . This high separation of charge pairs should be also assigned to the special designed morphology. In addition, wrapped like structure of g‒C3 N4 nanotubes with C ‒vacancy around HAp nanoplates play key role in separation of photo‒induced charge pairs, light diffusion, and high light harvesting within hollow nanotube. It can be highlighted that the composite degraded more than 95% of 4‒nitrophenol during 90 min that after 5 runs the photocatalytic activity was not significantly changed. Graphical abstract: Depicted proposed mechanism of photocatalytic degradation of 4-NP on the 3D g‒C3 N4 nanotubes/2D HAp nanoflakes thin film. Super oxide radicals play main role in photocatalytic degradation. Image 1 Highlights: New HAp nanoflakes synthesization without any template by novel method Sol-EPD. New Sol-EPD synthesized of g‒C3 N4 nanotubes/HAp nanoflakes composited thin film. Efficient photocatalytic degradation of aqueous 4‒NP by new and high stable HAp/g-C3 N4 . High separated photogenerated h‒e/low recombination by photoelectrochemical study.