One-Step Multi-Doping Process for Producing Effective Zinc Oxide Nanofibers to Remove Industrial Pollutants Using Sunlight

Abstract

Doping processes for optical materials are one of the driving forces for developing efficient and clean technologies for decontamination of aquatic effluents through lowering their band gap energy to become effective in sunlight. The current study has used a non-conventional technique for doping zinc oxide by multi metals, non-metals and organic dyes through a one-step process. In this trend, Zn-Al nanolayered structures have been used as hosts for building host–guest interactions. Organic dyes that have inorganic species of iron, nitrogen and sulfur have been used as guests in the intercalation reactions of Zn-Al layered double hydroxides. By intercalating green dyes, organic–inorganic nanohybrids were formed as nanolayered structures with expanding interlayered spacing to 2.1 nm. By changing the concentration of green dyes and thermal treatment, series of nanofibers and nanoplates of zinc oxides were formed and doped by aluminum, iron and sulfur in addition to colored species. The optical properties of the multi-doped zinc oxide indicated that it became suitable for solar applications because its band gap energy decreased from 3.30 eV to 2.80 eV. The experimental and kinetic results of the multi-doped zinc oxide concluded that the colored pollutants were effectively removed during 50 min of sunlight irradiation.

New Approach for Designing Zinc Oxide Nanohybrids to Be Effective Photocatalysts for Water Purification in Sunlight

“…The first one depends on the amount of energy which was absorbed by the photocatalyst as seen in the Reaction (2). The second reaction is the movement and separation of light-induced electrons-holes, as shown in the Reactions (3) and ( 4).…”

“…These results were confirmed by calculating their optical band gap energies. The band gap energy was determined through plotting the relation (αhν) 2 against energy (hν), as seen in Figure 10d-f. The band gap energy Eg of ZOA was calculated by drawing the tangent to the axis of energy to determine the optical band gap energy at (αhν) 2 of 0.…”

“…Therefore, they belong to the colored hazardous pollutants. Photocatalytic degradation seems as one of the benign solutions for purifying water from organic dyes using photocatalysts and sunlight [1][2][3]. For solving these environmental problems, semiconductor photocatalysts are very familiar in this trend [4][5][6][7].…”

Designing Novel Strategy to Produce Active Nanohybrids in Sunlight for Purification of Water Based on Inorganic Nanolayers, Magnetic Nanocomposites and Organic Species

“…Therefore, they belong to the colored hazardous pollutants. Photocatalytic degradation seems as one of the benign solutions for purifying water from organic dyes using photocatalysts and sunlight [6][7][8]. For solving these environmental problems, semiconductors photo-catalysts are very familiar in this trend [9][10][11][12].…”

Designing inorganic–magnetic–organic nanohybrids for producing effective photocatalysts for the purification of water

“…Photocatalytic degradation is a benign solution for purifying water from organic dyes using photocatalysts and light. [3][4][5] Semiconductor photocatalysts are very familiar in this area to solve environmental problems and purify wastewater. [6][7][8][9] According to the basic principle of heterogeneous photocatalysis, the electronic structure of a semiconductor has a strong effect on the performance of photocatalytic degradation of pollutants.…”