Visible Light Photocatalysis in Bismuth Oxyiodide Systems

Visible light photocatalysis in bismuth oxyiodide (BiOI) systems leverages the intrinsic narrow bandgap and two-dimensional layered structure of BiOI to harness solar photons for chemical transformations. The matlockite-type lattice of BiOI comprises alternating [Bi2O2] layers and iodine sheets, which facilitate strong visible-light absorption (approx. 450–600 nm) and internal electric fields that support charge separation. However, rapid recombination of photogenerated electrons and holes and limited surface reaction sites have prompted the engineering of heterostructures, composites and nanostructured morphologies. Strategies include coupling BiOI with carbonaceous supports, metal oxides or conductive polymers to form heterojunctions that extend optical response, promote interfacial charge transfer and suppress recombination. Morphological control—from exfoliated nanosheets to hierarchical microspheres—enhances surface area and exposes reactive facets, optimising photocatalytic performance for water oxidation, pollutant degradation and solar fuel production. Recent advances demonstrate scalable synthesis routes, tunable surface chemistry and composite architectures that improve quantum efficiency and operational stability. These developments underscore the global significance of BiOI-based photocatalysts in environmental remediation and sustainable energy, while ongoing challenges focus on long-term durability, cost-effective fabrication and integration into device platforms.

Research from Nature Portfolio

Recent studies have demonstrated the fabrication of BiOI/activated carbon composites via a green one-step synthesis that produces hierarchical micro- and nanostructures. In this approach, BiOI nanosheets grow tightly on activated carbon, forming Bi–C bonds that serve as bridges for rapid electron transfer. The resultant heterojunction displays a red-shifted absorption edge, expanded visible-light harvesting and abundant interfacial contacts. These features collectively suppress charge recombination and shorten pollutant diffusion pathways. Under visible-light irradiation, the optimised composite achieves greater than 95 per cent degradation of Rhodamine B within 120 minutes—over three times the rate of pristine BiOI—highlighting the efficacy of carbon integration in boosting photocatalytic activity and suggesting a promising route for scalable environmental applications.

Visible Light Photocatalysis in Bismuth Oxyiodide Systems publication trend

The graph below shows the total number of articles in visible light photocatalysis in bismuth oxyiodide systems across all publications each year (not limited to Nature Index journals).

Technical terms

Photocatalysis: Acceleration of a chemical reaction by a substance that absorbs light and generates reactive electron–hole pairs.

Bandgap: Energy difference between the valence and conduction bands of a semiconductor, determining the threshold photon energy for electron excitation.

Heterojunction: Interface between two distinct semiconductors where band alignment promotes charge separation and transfer.

Charge carrier separation: Process by which photogenerated electrons and holes are spatially separated to prevent recombination and enable redox reactions.

Photoelectrochemical water oxidation: Light-driven process in which photogenerated holes oxidise water to evolve oxygen at the anode of a photoelectrochemical cell.

References

1. Bismuth oxyhalides: synthesis, structure and photoelectrochemical activity. Chemical Science (2016).
2. Electronic Structure and Optical Properties of BiOI as a Photocatalyst Driven by Visible Light. Catalysts (2016).
3. Micro and nano hierachical structures of BiOI/activated carbon for efficient visible-light-photocatalytic reactions. Scientific Reports (2017).
4. ZnO/BiOI heterojunction photoanodes with enhanced photoelectrochemical water oxidation activity. Applied Catalysis B Environment and Energy (2023).
5. Tuning Surface Chemistry in 2D Layered BiOI by Facile Liquid‐Phase Exfoliation for Enhanced Photoelectrocatalytic Oxygen Evolution. Small Structures (2024).