Honeycomb-like ZnO Mesoporous Nanowall Arrays Modified with Ag Nanoparticles for Highly Efficient Photocatalytic Activity

Abstract

A new structure of honeycomb-like ZnO mesoporous nanowall arrays (MNWAs) with highly efficient photocatalytic activity was designed and successfully synthesized on Al foil by hydrothermal method. The nanowalls of ZnO-MNWAs have mesopores, which possess a large surface area. The visible light absorption of ZnO-MNWAs was efficiently stronger than ZnO nanowire, resulting in that the photocatalytic activity of ZnO-MNWAs, whose bandgap energy was 3.12 eV, was 5.97 times than that of ZnO nanowires in the degradation of methyl orange. Besides, Al foil acted as a good electron conductor which was beneficial to the separation of photo-induced electron-hole pairs. After modifying ZnO-MNWAs with a proper amount of Ag nanoparticles (NPs), photocatalytic activity could be further enhanced. The photocatalytic activity of ZnO-MNWAs with the optimal amount of Ag NPs was 9.08 times than that of ZnO nanowires and 1.52 times than that of pure ZnO-MNWAs.

ZnO Microflowers Grown by Chemical Bath Deposition: A Low-Cost Approach for Massive Production of Functional Nanostructures

“…Al(OH) 4 − promote the lateral growth of Zn-based nanostructure by binding the Zn 2+ terminated planes and obstructing the growth along the (0001) direction. This is also confirmed by the fact that the growth rate and the quality of ZnO NWLs are affected by the generation rate of Al(OH) 4 − [8,37,38]. Post-annealing processes were demonstrated to convert the as-grown nanowalls in pure ZnO [30].…”

“…The layered basic zinc salts (LBZS), for example, are species characterized by a lamellar structure, with high surface area, that, under particular conditions of synthesis [36], represent an intermediate phase of the formation of ZnO in solution. A particular ZnO sheets-like nanostructure is represented by nanowalls [8,30,37,38] that is commonly generated in a zinc salt-based aqueous solution using an Al-covered substrate. It was observed that the Al has a significant role in generating the morphological shape of the nanowalls through the Al(OH) 4…”

Solar-Light-Driven Efficient ZnO–Single-Walled Carbon Nanotube Photocatalyst for the Degradation of a Persistent Water Pollutant Organic Dye

“…Photocatalysis is becoming an increasingly popular choice for the degradation of pollutants, particularly for wastewater with relatively low concentrations of recalcitrant organic constituents. Photocatalysis offers numerous advantages over alternative techniques; these advantages include total mineralization, which avoids subsequent waste disposal problems; low operating costs; easy accessibility; high performance; and efficient action under ambient environmental conditions [5,6].…”

Facile Template In-Situ Fabrication of ZnCo2O4 Nanoparticles with Highly Photocatalytic Activities under Visible-Light Irradiation

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