Photocatalytic degradation of methylene blue and rhodamine B using one-pot synthesized nickel oxide grafted glycine (NiO @GLY) nanostructured: Oxygen vacancies effect

Abstract

A venerable challenge in environmental and materials science is the degradationof organic contaminants from wastewater using visible-light irradiation. The nickel oxide nanocomposite was synthesized using the facile one-pot combustion method at 550 °C. XRD, TEM, and N2 Sorption analysis confirmed the existence of mesoporous textured surfaces. Both spherical and hexagonal nanocrystals were produced with particle sizes ranging from 30 to 56 nm. The hexagonal nanocrystals appeared by increasing the glycine loading. The particle size of as-synthesized NiO @GLY was about 5–16 nm, with spherical morphology. The as-prepared hybrid composites were used to degrade harmful dyes. These produced systems seem to be governed by the interaction involving negatively charged nickel oxide nanoparticles and the amino group of glycine, as evidenced by zeta potential management. The degradation mechanism was found to follow the pseudo-first-order kinetics. S4 shows a promising result with degradation efficiency of 99 % methylene blue, 96 % rhodamine B, and 93 % for the mixed dye. The enhancement is related to oxygen vacancies, which support the photocatalyst's activity and stability.