Photodegradation of orange II dye using p-n junction NiO/TiO2 composite, and assessment of its biological activities
Tamanna Gul, Shujaat Ahmad, Idrees Khan, Ibrahim Khan, Mazen Almehmadi, Ahad Amer Alsaiari, Mamdouh Allahyani, Khalid Saeed
Abstract
The chemical reduction method was used to synthesize nickel oxide particles (NiO) and NiO supported on titanium dioxide (NiO/TiO2 nanocomposite). The composites were characterized through scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The morphological investigation showed that pseudocubic NiO are present in dispersed as well as agglomerated forms. Whereas NiO particles (<200 nm) are evenly deposited over the surface of TiO2 in NiO/TiO2 composite. The formation of NiO and NiO/TiO2 was also verified by XRD analysis. The synthesized NiO and NiO/TiO2 were used as photocatalysts for the degradation of Orange II (OII) dye. According to the degradation investigation, both NiO and NiO/TiO2 composite degraded OII dye more efficiently when exposed to UV light. The results indicated that NiO degraded 93% and NiO/TiO2 composites degraded approximately 96% of OII dye within 30 min. Both photocatalysts are highly sustainable and have significant OII dye degradation recyclability. Moreover, NiO and NiO/TiO2 exhibited promising bioactivities (antioxidant activity of 80%) against the pathogenic bacteria Citrobacter and Providencia, which is comparable with the standard ascorbic acid (88%).