Journal of Ultrafine Grained and Nanostructured Materials

Journal of Ultrafine Grained and Nanostructured Materials

Effect of Boron Doping on the Structure and Band Gap of ZnO Nanowires Grown by Anodizing: Toward Water Splitting Applications

Document Type : Research Paper

Authors
Samaneh Bordbar
shahin Khameneh asl
shahab khameneh Asl
Hakimeh ghazaie
Mobin Dehkharghani
Department of Materials Engineering, Faculty of Mechanical Engineering, University of Tabriz, Tabriz 51666–16471, Iran
10.22059/jufgnsm.2025.02.09
Abstract
Zinc oxide (ZnO) nanowires are promising for solar-driven hydrogen production, but their wide band gap (≈3.3 eV) limits absorption to the ultraviolet (UV) region. This study investigates the effect of boron (B) doping on the structural and optical properties of ZnO nanowires to enhance their photocatalytic potential. ZnO nanowires were synthesized by anodizing high-purity zinc foil in a sodium bicarbonate/ethylene glycol electrolyte at 5 V and 29 °C for 40 min under ambient pressure, followed by annealing at 200 °C. Boron doping was performed by immersion in boric acid (0.025–0.1 M) for 1–10 h, followed by annealing at 250 °C. Characterization using field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and diffuse reflectance spectroscopy (DRS) revealed that boron content increased from 0 at.% to 23.02 at.% with immersion time and varied from 8.22 at.% to 14.87 at.% with boric acid concentration. Doping increased nanowire diameter from 65.3 nm to 113.8 nm (≈74.4%) and length from 4.63 µm to 4.85 µm (≈4.7%), while reducing the surface-to-volume ratio by ≈36.6%. The optical band gap decreased up to ≈24.2%, enhancing visible-light absorption. These results demonstrate that boron-doped ZnO nanowires exhibit improved light harvesting and structural properties, making them efficient candidates for photocatalytic and photoelectrochemical hydrogen generation under solar illumination.
Keywords
Zinc oxide
Anodization
Photocatalysis
Hydrogen production
Nanooxide coating, Boron-doped
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Journal of Ultrafine Grained and Nanostructured Materials
Volume 58, Issue 2
December 2025
Pages 242-254

  • Receive Date 01 August 2025
  • Revise Date 03 October 2025
  • Accept Date 08 October 2025