Photoanode with Enhanced Performance Achieved by Coating BiVO₄ onto ZnO-Templated Sb-Doped SnO₂ Nanotube Scaffold

Abstract

The performance of BiVO photoanodes, especially under front-side illumination, is limited by the modest charge transport properties of BiVO. Core/shell nanostructures consisting of BiVO coated onto a conductive scaffold are a promising route to improving the performance of BiVO-based photoanodes. Here, we investigate photoanodes composed of thin and uniform layers of BiVO particles coated onto Sb-doped SnO (Sb:SnO) nanotube arrays that were synthesized using a sacrificial ZnO template with controllable length and packing density. We demonstrate a new record for the product of light absorption and charge separation efficiencies (η × η) of ∼57.3 and 58.5% under front- and back-side illumination, respectively, at 0.6 V. Moreover, both of these high η × η efficiencies are achieved without any extra treatment or intentional doping in BiVO These results indicate that integration of Sb:SnO nanotube cores with other successful strategies such as doping and hydrogen treatment can increase the performance of BiVO and related semiconductors closer to their theoretical potential.

Niobium Doping in BiVO4: Interplay Between Effective Mass, Stability, and Pressure

“…Clinobisvanite structure is a widely used BiVO 4 structure as opposed to its tetragonal counterpart for its enhanced photocatalytic property. [3,5,7,12,[14][15][16]18,34] It belongs to the monoclinic crystal system and has the space group of C2/c (space group no. 15).…”

“…Given the present state of global warming and the future availability of fossil fuels, it has been a frantic search in recent decades to find such ‘suitable’ materials. In recent years, BiVO 4 attracts attention as a potential photoanode for water oxidation as well as a photo‐catalyst for hydrogen evolution via water splitting and environmental remediation by degrading pollutants . Earth‐abundant for low‐cost fabrications, near ideal band gap (2.4–2.5 eV),, for efficient light absorption at visible range, the relative positions of its conduction and valence bands compared to the water reduction potentials,, its optoelectronic responses and nontoxicity are some of the main reasons for this.…”

“…In recent years, BiVO 4 attracts attention as a potential photoanode for water oxidation as well as a photo-catalyst for hydrogen evolution via water splitting and environmental remediation by degrading pollutants. [1][2][3][4][5][6] Earthabundant for low-cost fabrications, near ideal band gap (2.4-2.5 eV) [2,3,7] for efficient light absorption at visible range, the relative positions of its conduction and valence bands compared to the water reduction potentials, [8,9] its optoelectronic responses and nontoxicity are some of the main reasons for this. In fact, monoclinic BiVO 4 as a photo-catalyst has been said to achieve one of the highest hydrogen production efficiency among the oxide materials.…”

“…In fact, monoclinic BiVO 4 as a photo-catalyst has been said to achieve one of the highest hydrogen production efficiency among the oxide materials. [1][2][3]7,8,10,11] Despite these advantages as a potential photo-catalyst, BiVO 4 has some limitations, which attribute to its low efficiency. Poor transport of photo-induced carriers, electron-hole recombination and slow reaction kinetics at the interface are the crucial limitations of pristine BiVO 4 .…”

Preparation of nanoporous BiVO 4 /TiO 2 /Ti film through electrodeposition for photoelectrochemical water splitting

“…However, the conduction band (CB) level is low and it is unsuitable for O 2 formation. The high-energy electrons excited by light usually relax in the bottom of the CB quickly owing to its weak charge-carrier separation [7,8]. …”