Photocatalytic Activity Across Solar Spectrum

Photocatalytic activity across the solar spectrum encompasses the conversion of solar photons into chemical or electrical energy via semiconductor or hybrid materials capable of harvesting ultraviolet, visible and near-infrared (NIR) light. Traditional photocatalysts, such as titanium dioxide, efficiently absorb ultraviolet radiation but are limited by the small proportion of UV in sunlight. Contemporary research focuses on widening the absorption window into the visible and NIR regions, which together constitute over 90 % of the solar irradiance reaching Earth’s surface. Strategies include bandgap engineering to narrow energy thresholds, constructing heterojunctions to promote charge separation, incorporating plasmonic nanostructures to amplify local electromagnetic fields and adopting bio-inspired architectures to boost long-wavelength harvesting. The global significance of full-spectrum photocatalysis spans water splitting for hydrogen production, carbon dioxide reduction to fuels and environmental remediation through pollutant degradation. Achieving robust, stable and scalable photocatalytic systems that operate under full-sunlight conditions remains a central challenge, driven by the need for sustainable energy solutions and green chemistry applications.

Research from Nature Portfolio

Recent studies have demonstrated innovative approaches to extend photocatalytic response into the NIR. One foundational work employed bio-inspired plasmonic nanoarchitectures, mimicking butterfly-wing micro- and nano-structures, to assemble light-harvesting antennas on a semiconductor substrate. Finite-difference time-domain simulations and experimental studies revealed up to 25 % enhancement in far-red to NIR absorption and a over threefold increase in local electric-field amplitude, thereby boosting electron–hole formation rates. Another investigation developed P25/(NH₄)xWO₃ nanocomposites synthesised via a one-step hydrothermal route. Mixed valence states of tungsten impart broad optical absorption from UV to NIR and synergistic interfacial effects that drive efficient degradation of organic dyes under full-spectrum illumination. More recently, lattice-matched morphological heterojunctions comprising ternary alloy BiSeTe nanotubes integrated with ultrathin nanosheets achieved an incident photon-to-current conversion efficiency of 36 % at 800 nm. The hierarchical heterojunction simultaneously broadens light-harvesting range and facilitates rapid charge separation, marking a significant advance in near-infrared-active photoelectrochemical systems.

Photocatalytic Activity Across Solar Spectrum publication trend

The graph below shows the total number of articles in photocatalytic activity across solar spectrum across all publications each year (not limited to Nature Index journals).

Technical terms

Photocatalysis: A process in which a material absorbs photons and catalyses chemical transformations, typically by generating reactive charge carriers.

Bandgap: The energy difference between the valence band and conduction band of a semiconductor that determines the threshold photon energy for electronic excitation.

Heterojunction: An interface between two different semiconductors that facilitates spatial separation of photogenerated electrons and holes, reducing recombination.

Plasmonic nanostructure: A metal nanostructure that supports collective oscillations of conduction electrons (surface plasmons), enhancing local electromagnetic fields and light absorption.

Photon up-conversion: A nonlinear optical process whereby two or more low-energy photons are absorbed and re-emitted as a single higher-energy photon, extending photocatalytic action to longer wavelengths.

References

1. Bio-inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red-to-Near Infrared Solar Photocatalysis. Scientific Reports (2016).
2. A P25/(NH4)xWO3 hybrid photocatalyst with broad spectrum photocatalytic properties under UV, visible, and near-infrared irradiation. Scientific Reports (2017).
3. Boosting photoelectrochemical efficiency by near-infrared-active lattice-matched morphological heterojunctions. Nature Communications (2021).
4. Recent Developments in Heterogeneous Photocatalysts with Near-Infrared Response. Symmetry (2022).
5. NaBiS2 as a Novel Indirect Bandgap Full Spectrum Photocatalyst: Synthesis and Application. Catalysts (2020).
6. Enhanced Photocatalytic Performance under Visible and Near-Infrared Irradiation of Cu1.8Se/Cu3Se2 Composite via a Phase Junction. Nanomaterials (2017).