Photocatalytic Mechanisms in Bismuth-Based Photocatalysts

Photocatalysis using bismuth-based semiconductors has emerged as a robust route to address environmental and energy challenges. Materials such as bismuth oxyhalides, Aurivillius-phase oxides and bismuth molybdates exhibit unique layered structures and adjustable band gaps that facilitate visible-light harvesting. Upon irradiation, photogenerated electrons and holes migrate to the surface, where they react with adsorbed species to produce reactive oxygen species or effect redox conversions. Key strategies to enhance performance include heterojunction formation to promote charge separation, defect engineering to introduce oxygen vacancies that extend light absorption and internal electric fields at interfaces to direct carrier migration. Surface functionalisation with noble metals or carbon-based semiconductors further accelerates electron transfer and suppresses recombination. These mechanistic insights underpin diverse applications from organic pollutant degradation and antibiotic removal to CO₂ reduction and fine chemical synthesis, illustrating the global importance of optimised bismuth-based photocatalysts.

Research from Nature Portfolio

Recent studies have harnessed heterostructure and defect engineering to advance photocatalytic efficiency. One investigation demonstrated the in-situ creation of surface oxygen vacancies on exposed facets of bismuth oxybromide nanosheets via chelation, which deepens visible-light absorption and boosts charge-carrier separation through vacancy-induced states. Another work reported Pt-decorated g-C₃N₄/Bi₂MoO₆ composites in which Pt nanoparticles anchor on a layered heterojunction, markedly expanding surface area and facilitating rapid electron transfer, leading to enhanced dye degradation under visible irradiation. More recently, a zero-dimensional/two-dimensional heterojunction of Bi₂WO₆ and BiOCl was constructed, whereby an internal electric field at the interface drives efficient electron migration, resulting in significant improvements in antibiotic photodegradation and long-term stability.

Photocatalytic Mechanisms in Bismuth-Based Photocatalysts publication trend

The graph below shows the total number of articles in photocatalytic mechanisms in bismuth-based photocatalysts across all publications each year (not limited to Nature Index journals).

Technical terms

Photocatalysis: Acceleration of a chemical reaction by a catalyst activated by light.

Band gap: Energy difference between the valence band and conduction band in a semiconductor.

Heterojunction: Interface between two semiconductors that facilitates charge separation.

Z-scheme: Photocatalytic system mimicking natural photosynthesis, maximising redox potential by selective charge recombination.

Oxygen vacancy: Missing oxygen atom in a lattice that can introduce states to trap charges and extend light absorption.

Reactive oxygen species: Highly reactive molecules such as superoxide and hydroxyl radicals generated during photocatalysis.

References

1. A Chelation Strategy for In-situ Constructing Surface Oxygen Vacancy on {001} Facets Exposed BiOBr Nanosheets. Scientific Reports (2016).
2. Pt nanoparticles decorated heterostructured g-C3N4/Bi2MoO6 microplates with highly enhanced photocatalytic activities under visible light. Scientific Reports (2019).
3. Bi2WO6–BiOCl heterostructure with enhanced photocatalytic activity for efficient degradation of oxytetracycline. Scientific Reports (2020).
4. In situ synthesis of three-dimensional core–shell structure Bi2WO6/BiOCl and photocatalytic degradation of trinitrotoluene wastewater. Advanced Composites and Hybrid Materials (2025).
5. Electrodeposition of nanostructured Bi2MoO6@Bi2MoO6–x homojunction films for the enhanced visible-light-driven photocatalytic degradation of antibiotics. Applied Catalysis B Environment and Energy (2022).