Phytogenic Synthesis and Characterization of NiO-ZnO Nanocomposite for the Photodegradation of Brilliant Green and 4-Nitrophenol

Abstract

The NiO-ZnO nanocomposite (NiO-ZnO NC) was synthesized by ecofriendly process by using Diospyros kaki (D. kaki) extract of leaves as reducing and capping agents. X-ray diffraction (XRD) was used for examined crystallinity, cell dimensions, and crystallite size (7.6 nm). To determine the purity of sample and weight percentage, energy dispersive X-ray (EDX) is used. The surface morphology was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By using Fourier transform infrared spectroscopy (FTIR), functional groups in samples were determined. By using diffuse reflectance data (DRS), band gap energy calculated via Tauc plot was 3.23 eV. The photocatalytic activity was checked against brilliant green (BG) and 4-nitrophenol (4-NP) and 92.5% and 69.7% of brilliant green (BG) and 4-nitrophenol (4-NP) were degraded with rate of degradation which were 0.0281 and 0.011 min−1.

Green Synthesis of NiO-SnO2 Nanocomposite and Effect of Calcination Temperature on Its Physicochemical Properties: Impact on the Photocatalytic Degradation of Methyl Orange

“…The transformation holes occurred from the valence band of SnO 2 to the valence band of NiO. Consequently, excited electrons shifted from the conduction band of NiO to the conduction band of SnO 2 [ 22 ]. This transformation of charge carrier entity to either side results in the complete elimination of the possible recombination of positive and negative charges.…”

“…SnO 2 NPs have been fabricated using physical and chemical methods such as laser ablation, the sol–gel method, spray pyrolysis, microemulsion, microwaves, electrochemical deposition, co-precipitation, and hydrothermal, sonochemical, solvothermal, and non-aqueous routes [ 20 , 30 , 31 ]. Importantly, the paucity of reports on the photodegradation of dyes with NiO NPs and SnO 2 NPs compared to TiO 2 NPs and ZnO NPs [ 7 , 13 , 14 , 18 , 21 , 22 , 32 ] justifies the present study.…”

“…Different types of metal and metal oxide nanoparticles have been synthesized for various applications, such as catalysis, energy storage devices, dye-based solar cells, and biomedicines [ 2 , 7 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…Tin oxide nanoparticles (SnO 2 NPs) are n-type semiconductors with a wide band gap (3.6 eV) [ 28 ]. Due to their strong oxidizing power, different morphologies, non-toxic nature, and high photochemical stability, SnO 2 NPs are one of the best choices for photocatalysts [ 19 , 21 , 22 ]. Owing to their properties such as low cost, electro-catalytic activity, high conductivity, and high chemical stability, SnO 2 NPs have also been used extensively in the arena of electrochemical sensing [ 29 ].…”

Adsorptive Detoxification of Congo Red and Brilliant Green Dyes Using Chemically Processed Brassica Oleracea Biowaste from Waste Water

“…Various in-practice traditional methods that include photochemical, biological, and chemical treatments [9][10][11] are in practice for the removal of such effluents, such as ozonation [12], coagulation [13], fungal decolorization [14][15][16], adsorption, flocculation, and electrochemical technique [17,18]. All these techniques are efficient in one way or the other but are complicated and problematic towards various environmental aspects being expensive and produce several hazardous by-products [19,20].…”