Bilayer TiO₂/Mo-BiVO₄ Photoelectrocatalysts for Ibuprofen Degradation

Area of Science:

• Materials Science
• Photocatalysis
• Environmental Engineering

Background:

• Heterojunctions between BiVO₄ and other semiconductors improve charge transport for pollutant degradation.
• Recalcitrant pharmaceutical pollutants pose environmental challenges requiring advanced remediation techniques.
• Titanium dioxide (TiO₂) is a benchmark photocatalyst, while Mo-doped BiVO₄ absorbs visible light.

Purpose of the Study:

• To fabricate and evaluate a TiO₂/Mo-BiVO₄ bilayer photoanode for enhanced photoelectrocatalytic performance.
• To investigate the effect of the heterostructure on photocurrent generation and pharmaceutical pollutant degradation.
• To understand the role of light harvesting and charge transfer at the TiO₂/Mo-BiVO₄ interface.

Main Methods:

• Fabrication of a mesoporous TiO₂ overlayer (using P25 titania) on Mo-doped BiVO₄ inverse opal films.
• Post-thermal annealing to densify the bilayer structure.
• Evaluation of photoelectrochemical performance and photoelectrocatalytic degradation of ibuprofen under visible and UV-Vis light.

Main Results:

• The TiO₂/Mo-BiVO₄ bilayer photoanode exhibited significantly enhanced photocurrent density compared to individual layers.
• The heterostructure demonstrated improved photoelectrocatalytic degradation of ibuprofen.
• Enhanced performance is attributed to improved light harvesting via backscattering and efficient charge transfer at the interface.

Conclusions:

• The fabricated TiO₂/Mo-BiVO₄ bilayer photoanode is a promising material for efficient photoelectrocatalytic degradation of pharmaceutical pollutants.
• The heterostructure design effectively enhances light utilization and charge separation, leading to superior performance.
• This approach offers a viable strategy for developing advanced photocatalysts for environmental remediation.