Insight into the photocatalytic properties of diatomite@Ni/NiO composite for effective photo-degradation of malachite green dye and photo-reduction of Cr (VI) under visible light

Liu, Guohong; Abukhadra, Mostafa R.; El-Sherbeeny, Ahmed M.; Mostafa, Almetwally M.; Awwad, Emad Mahrous

doi:10.1016/j.jenvman.2019.109799

Cited by 57 publications

(40 citation statements)

References 52 publications

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“…This is related to the endothermic behaviors of these reactions, which make the high temperature values favorable to enhance the kinetic energy and prompt the transformation rates. 14 , 26 Moreover, such conditions are valuable in reducing the viscosity, immiscibility, and mass transfer resistance, which enhance the homogeneity of the mixture and the interaction chances between the reacted components. 27 , 28 Based on the previous findings, a reaction temperature of 80 °C and a reaction interval of 100 min are the best conditions for the transesterification of WCO over NiO, NiO@D, and Ni/NiO@D.…”

Section: Results and Discussionmentioning

confidence: 99%

“… 11 , 13 The doping process of NiO with Ni in its metallic form was recommended as an effective method to enhance the chemical and physical properties of the structure as well as its catalytic performance. 14 …”

Section: Introductionmentioning

confidence: 99%

“…Additionally, as a heterogeneous catalyst in biodiesel production, it is of limited efficiency and it achieved low biodiesel yields . Thus, researchers have directed their attention to tackling these drawbacks and inducing its reactivity by doping its structure with other metals, integrating it in composites, and by supporting it in a significant carrier or substrate that provides promising properties as an effective catalyst of thermo-chemical stability. , The doping process of NiO with Ni in its metallic form was recommended as an effective method to enhance the chemical and physical properties of the structure as well as its catalytic performance …”

Section: Introductionmentioning

confidence: 99%

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Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni⁰ Metal: Response Surface Studies

et al. 2021

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Two types of NiO-based composites (NiO@diatomite and Ni/NiO@diatomite) were synthesized as modified products of enhanced catalytic performances during the transesterification reactions of waste cooking oil. The influence of the diatomite substrate and the integration of metallic Ni 0 in inducing the catalytic activity were evaluated in a series of transesterification reactions. The experimental conditions were adjusted according to the response surface methodology and the central composite statistical design. Experimentally, the diatomite substrate and the Ni 0 metal induced the efficiency of the reaction to achieve a yield of 73.4% (NiO@diatomite) and 91% (Ni/NiO@diatomite), respectively, as compared to 66% for the pure phase (NiO). This was obtained under experimental conditions of 80 °C temperature, 100 min time, 12:1 methanol/oil molar ratio, and 3.75 wt % loading. The theoretical optimization functions of the designs suggested enhancement to the experimental conditions to achieve a yield of 76.3% by NiO@diatomite and 93.2% by Ni/NiO@diatomite. This reflected the role of the diatomite substrate in enhancing the surface area, the adsorption of fatty acids, and the exposure of the catalytic sites in addition to the effect of the Ni 0 metal in enhancing the catalytic reactivity of the final product. Finally, the biodiesel produced over Ni/NiO@diatomite as the best product was of acceptable properties according to the international standards.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni⁰ Metal: Response Surface Studies

et al. 2021

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“…Transition metals and metal oxides have been receiving significant attention because of their diverse applications in the field of catalysis (1,2) , batteries (3) , electromagnetism (4) , gas sensors (5,6) , and photocatalysis (7,8) . These metal/metal oxide-based nanomaterials possess a large surface-to-volume ratio, unique adsorptive properties, surface defects, https://www.indjst.org/ and fast diffusivities (9,10) . These materials are of much interest because of their unique shape and size-dependent properties (11,12) as compared to bulk crystals with the same chemical composition.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous removal of lead and cadmium ions by nickel oxide nanoparticles

Sardar¹

2021

IJST

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Objectives: To study the simultaneous removal of metal ions to understand the dynamics of the adsorption process for the assessment of the actual potential of an adsorbent in real-life applications. Methods: A one-step hydrothermal method was employed for the synthesis of nanomaterial. The hydrothermal treatment was performed at 110 o C for 3 hours and calcined at 300 o C for 2 hr to complete the nickel oxide nanoparticle synthesis. A systematic study of metal ion adsorption onto the nickel oxide nanoparticle was conducted to evaluate the maximum adsorption capacity and to understand the adsorption behaviour of the metal ions in presence of the others. The estimation of metal ion adsorption was done by measuring the residual concentrations using an atomic absorption spectrophotometer. Findings: The microscopic and spectroscopic characterizations confirmed the formation of nickel oxide nanostructures. The experimental results suggested that the adsorption process follows the Langmuir isotherm and the pseudo-secondorder model for metal ion adsorption in single and mixed solutions. A synergistic effect was observed for Pb (II) adsorption and an antagonistic effect for Cd (II) adsorption. The maximum adsorption capacity of ~650 mg/g of Pb (II) and ~475 mg/g of Cd (II) were noticed for simultaneous adsorption by the NiO nanoparticle. Novelty/improvement: The presence of more than one heavy metal ion in the wastewater is obvious, and one kind of metal ion may interface with the adsorption behaviour of the others. Further, limited studies on simultaneous adsorption of metal ions using metal-oxide nanoparticles are available in the literature. Hence, this work will provide an idea about the applicability of the NiO nanoparticle for real-life applications.

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“…[45][46][47] Therefore, an S-scheme heterojunction is needed to couple BiOBr with another semiconductor. [48] NiO is a standard p-type semiconductor with strong reductive ability, which is widely applied in heavy metal reduction, [49] photocatalytic hydrogen production, [50][51][52] CO 2 photoreduction, [53] and photocatalytic overall water splitting. [54,55] An intrinsic NiO semiconductor possesses a wide bandgap of about 4 eV in theory.…”

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BiOBr/NiO S‐Scheme Heterojunction Photocatalyst for CO₂ Photoreduction

et al. 2021

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The artificial photosynthesis of hydrocarbon fuels by photocatalysts is a green and sustainable energy regeneration process, which is essential for environmental protection. [1,2] However, so far, the efficiency of CO 2 photoreduction is relatively low compared with that of photocatalytic H 2 production and contaminants removal degradation. [3][4][5][6] On one hand, the recombination of photogenerated charges inside the semiconductor and on the surface is serious, leading to the severe loss of photogenerated carriers. [7][8][9][10][11][12][13] On the other hand, CO 2 molecules are thermodynamically stable. [14,15] Therefore, a high energy barrier needs to be overcome to activate and hydrogenate CO 2 molecules, which requires robust reductive ability of the photocatalyst. [16] Meanwhile, the protons come from water oxidation; a robust oxidative ability is demanded. [17] S-scheme heterojunction photocatalyst promotes charge separation and maintains enough redox ability. [18][19][20][21][22][23][24][25] In this backdrop, it is feasible to fabricate S-scheme photocatalysts to improve the efficiency of CO 2 photoreduction. [15,26,27] Nevertheless, up to now, most of the S-scheme photocatalysts were achieved by two n-type semiconductors. [10,[28][29][30][31][32][33][34][35][36][37] Therefore, to fully understand the advantages of the S-scheme heterojunction and further improve CO 2 photoreduction activity, this gap needs to be filled.BiOBr, a p-type semiconductor, possesses appropriate conduction band (CB) and valence band (VB) positions, which becomes a promising candidate in our study. [38][39][40] Meanwhile, intense inherent polarization is derived from its layered structure with alternate Br and Bi-O layers. Therefore, a spontaneous internal electrical field (IEF) is formed and favorable for charge separation. [41][42][43][44] Therefore, BiOBr exhibits excellent CO 2 photoreduction performance by the cooperative effect of appropriate band structure and innate IEF. [42] However, low specific surface area, poor CO 2 adsorption ability, and weak reductive capability of BiOBr result in sluggish kinetics of CO 2 photoreduction. [45][46][47] Therefore, an S-scheme heterojunction is needed to couple BiOBr with another semiconductor. [48] NiO is a standard p-type semiconductor with strong reductive ability, which is widely applied in heavy metal reduction, [49] photocatalytic hydrogen production, [50][51][52] CO 2 photoreduction, [53] and photocatalytic overall water splitting. [54,55] An intrinsic NiO semiconductor possesses a wide bandgap of about 4 eV in theory. [56] In practice, synthesized NiO is a p-type semiconductor because of massive Ni vacancies, especially when heated at high temperatures. [51] These Ni vacancies not only narrow the bandgap but also improve the visible light absorption of NiO. [57] Yazdani et al. found that the bandgap of NiO varied from 3.35 to 1.55 eV with the change in annealing temperature. [58] On the contrary, flake morphologies are typical structures for nickel oxides or hydroxides, which...

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Insight into the photocatalytic properties of diatomite@Ni/NiO composite for effective photo-degradation of malachite green dye and photo-reduction of Cr (VI) under visible light

Cited by 57 publications

References 52 publications

Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni⁰ Metal: Response Surface Studies

Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni⁰ Metal: Response Surface Studies

Simultaneous removal of lead and cadmium ions by nickel oxide nanoparticles

BiOBr/NiO S‐Scheme Heterojunction Photocatalyst for CO₂ Photoreduction

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Insight into the photocatalytic properties of diatomite@Ni/NiO composite for effective photo-degradation of malachite green dye and photo-reduction of Cr (VI) under visible light

Cited by 57 publications

References 52 publications

Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni0 Metal: Response Surface Studies

Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni0 Metal: Response Surface Studies

Simultaneous removal of lead and cadmium ions by nickel oxide nanoparticles

BiOBr/NiO S‐Scheme Heterojunction Photocatalyst for CO2 Photoreduction

Contact Info

Product

Resources

About

Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni⁰ Metal: Response Surface Studies

Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni⁰ Metal: Response Surface Studies

BiOBr/NiO S‐Scheme Heterojunction Photocatalyst for CO₂ Photoreduction