DFT and experimental investigations on the photocatalytic activities of NiO nanobelts for removal of organic pollutants

• Published in: Journal of alloys and compounds 2021-02, Vol.855, p.157337, Article 157337
• Main Authors: Kitchamsetti, Narasimharao, Ramteke, Mrunmay S., Rondiya, Sachin R., Mulani, Sameena R., Patil, Madhuri S., Cross, Russell W., Dzade, Nelson Y., Devan, Rupesh S.
• Format: Article
• Language: English
• Subjects: Density functional theory; DFT; Dye degradation; etc; First principles; Nickel oxides; NiO nanobelt; Organic pollutant; Photocatalysis; Photocatalyst; Photodegradation; Pollutants; Rate constants; Scavenging; Wastewater treatment; X ray photoelectron spectroscopy; Xenon lamps
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.157337

NiO nanobelts synthesized using the hydrothermal method are explored for photocatalytic degradation of organic pollutants like RhB, MO, MB, and CV. The XPS analysis confirmed the formation of the stoichiometric NiO nanobelts. Few micrometer long cubic crystalline NiO nanobelts of the average thickness of ∼75 nm delivered a bandgap of 4.07 eV. The FTIR studies revealed that the mesoporous NiO nanobelts delivered stable photocatalytic activities after controlled irradiation under a xenon lamp. The kinetic studies showed the 79.1, 82.7, 76.7, and 89% degradation of MO, MB, CV, and RhB after 140 min at the rate constants (k) of 0.007, 0.008, 0.009, and 0.012 min−1, respectively. Complementary first-principles Density Functional Theory (DFT) and scavenging studies revealed the chemical picture and influence of the O2−, and photogenerated H+ from NiO nanobelts in the photocatalytic degradation of organic dyes. These studies corroborate the use of the NiO nanobelts in the stable and eco-friendly photocatalytic degradation activities of a wide range of organic pollutants. The adsorption of O2 on energetically more favored side-on and end-on geometries of interacting surface Ni sites enhanced the formation of O2− and OH- radicals on NiO nanobelts (left panel) and delivered excellent photocatalytic degradation of RhB dye (right panel). [Display omitted] •The synthesis of mesoporous NiO nanobelts via a cost-efficient hydrothermal technique.•DFT analysis of the photocatalytic activity of NiO nanobelts.•NiO nanobelts as an excellent photocatalyst for the removal of organic dyes.•The 89 % degradation of RhB dye after 140 min under a xenon lamp.