Search

Photocatalytic conversion of CO₂ typically uses concentrated feeds, hindering the direct conversion of ambient CO₂ to value-added products. Kar et al. report a flow reactor that produces syngas (a mixture of CO and H₂) through on-site utilization of air-captured CO₂ using light.

When coupled to electrodes, the photosystem II complex can participate in a photo-induced oxygen reduction mechanism via chlorophyll a pigments that competes against the desired water-oxidation charge transfer pathway.

Tracking immobilized molecular complexes under in situ conditions is vital for the development of next-generation catalysts, although the poor surface sensitivity of many techniques makes this challenging. Now, the role of the anchoring group in a nickel bis(terpyridine) complex has been elucidated by in situ gap-plasmon-assisted SERS coupled with DFT calculations.

Photoelectrochemical CO₂ reduction to multi-carbon alcohols in standalone devices driven only by sunlight is challenging. Now Rahaman et al. integrate a copper–palladium catalyst in a perovskite–BiVO₄ tandem device for solar-driven multi-carbon alcohol production.

A versatile solar-driven hybrid photoelectrochemical platform has been developed for the simultaneous conversion of greenhouse gas CO₂ and waste plastics into value-added fuels and chemicals with high efficiency and selectivity.

A water splitting system capable of operating stably using contaminated water sources for decentralized H₂ production would be a more practical approach towards solar H₂ production. A floating hybrid photocatalyst sheet device can simultaneously perform photocatalytic gas-phase water splitting and clean water production using contaminated water sources such as seawater and other waste waters.

Hydrocarbon selectivity in photoelectrochemical CO₂ reduction has been limited due to a lack of low-overpotential catalysts and high-photovoltage semiconductors. Here Cu nanoflowers are interfaced with perovskite light absorbers for bias-free conversion of CO₂ to ethane and ethylene coupled to water or glycerol oxidation.

Conversion of CO₂ to fuels or chemicals via artificial photosynthesis usually requires the assistance of organic additives or electricity. Now, a biohybrid system is reported consisting of a photocatalyst sheet and bacteria producing acetate and O₂ from CO₂ and H₂O using sunlight as the sole energy input.

Photoelectrochemical production of syngas from water and CO₂ is technologically attractive but overpotentials, low selectivity and catalyst cost remain challenging. Tunable syngas production integrating cobalt porphyrin catalysts with perovskite and BiVO₄ photoabsorbers is now shown.

Semi-artificial photosynthetic systems combine natural and synthetic features to overcome limitations of each approach to produce solar fuels. Sokol et al. integrate a dye-sensitized TiO₂ photoanode with the natural machineries, photosystem II and hydrogenase, to split water without additional applied bias.

Lead-halide perovskites are sensitive to humidity, which limits their use in water splitting applications. Here, the authors protect the perovskite layer with Field’s metal, driving photoelectrocatalytic hydrogen evolution in an aqueous solution for approximately one hour under constant illumination.

Carbonic anhydrase enzymatically catalyses CO₂ hydration, and its effect on enzymatic and heterogeneous CO₂ reduction has now been studied. Through the co-immobilization of carbonic anhydrase, it has been shown that faster CO₂ hydration kinetics are beneficial for enzymatic catalysis (using formate dehydrogenase) but detrimental for heterogeneous catalysts, such as gold.

This work introduces lightweight, leaf-like photoelectrochemical devices for unassisted water splitting and syngas production, which could be used in the fabrication of floating systems for solar fuel production.

In photoelectrochemical (PEC) cells, water oxidation to O₂, when coupled to CO₂ reduction, typically requires a pair of light absorbers or an applied bias voltage. Now, a bias-free PEC cell with a single sunlight absorber drives simultaneous CO₂ reduction to give formate, and the oxidation of an organic substrate in aqueous conditions.

Selective photocatalytic conversion of CO₂ into fuels without using sacrificial reagents and external bias has proved difficult. Addressing these challenges, Wang and colleagues fabricate wireless photocatalyst sheets comprising a molecular cobalt catalyst and metal oxide semiconductors that convert CO₂ and H₂O into formate and O₂.

A study introduces a novel method to grow single-crystal Cu₂O thin films with selected crystal orientations, highlighting enhanced bulk carrier mobility and carrier diffusion length along the [111] direction that yields Cu₂O photocathodes with improved performance.

Photoreforming can produce H₂ through the simultaneous reduction of water and the oxidation of organic molecules, such as those derived from biomass, but cheaper and more active photocatalysts are required. This study shows that CdS/CdO_x produces H₂ from unprocessed lignocellulose suspensions at high rates under solar illumination.

Although surface-bound molecular catalysts offer well-defined active sites on heterogeneous supports, it is challenging to identify key radical intermediates in the reaction mechanism. Now, a characterization method has been developed that combines film electrochemistry and EPR spectroscopy to track radical intermediates in real time, exemplified by alcohol oxidation with a surface-immobilized nitroxide.

Immobilized molecular catalysts can be efficient for the electroreduction of CO₂, but their practical applicability is hampered by the continued use of rare metals. Here, a photoelectrode based on an earth-abundant molecular catalyst with high CO₂ reduction performance is introduced.

By using in vivo ultrafast TA spectroscopy, extraction of electrons directly from photoexcited PSI and PSII in cyanobacterial cells using exogenous electron mediators is demonstrated.

The oxidation of water remains the kinetic bottleneck of solar-to-fuel synthesis. Now, spectroelectrochemical evidence together with density functional theory calculations show that charge accumulation determines the reaction mechanism on metal–oxide photoanodes. These insights reveal features that are common to the mechanisms of water oxidation carried out by other inorganic and biological systems.

Fuels synthesized using sunlight offer a sustainable solution for chemical energy storage, but inefficient utilization of the solar spectrum has limited their broader viability. This Review looks at how approaches that are complementary to one another can be employed to better exploit solar energy for sunlight-to-fuel conversion.

Photoelectrochemical devices are used for direct solar fuel production, but the stability of light absorbers can hamper their commercial prospects. Integrating a BiOI light absorber into a robust oxide-based architecture with a graphite paste conductive encapsulant results in photocathodes with long-term H₂ evolution activity.

This Review introduces solar reforming as an emerging technology to produce sustainable fuels and chemicals from diverse waste feedstocks using sunlight. The chemistry and concept of solar reforming, suggestions of key metrics and proposed directions to realize solar-powered refineries for a future circular economy are discussed.

Photoreforming is a sunlight-driven technology that can simultaneously reclaim the value in waste and contribute to renewable hydrogen production. This Review examines the advantages and challenges and identifies ways forward.

The electro- and photo-catalytic reduction of carbon dioxide are important processes in the context of developing a sustainable carbon-neutral economy. In this Review Article, the authors discuss how the local chemical environment in the proximity of the catalytic active site can influence the reactivity and selectivity of the processes and detail different approaches to achieve their modulation.

Progress in the field of photocatalytic CO₂ reduction has been constrained by a lack of comparability between studies. This Perspective provides recommendations for best practices in the undertaking and reporting of experimental data in this promising research area.

This Review summarizes recent progress on enzymatic and microbial hybrid systems for solar-to-fuel conversion, as well as the challenges the field is facing.

A light-driven enzyme that oxidizes H₂O, photosystem II has inspired a wealth of solar fuels research and is used directly in semi-artificial photosynthesis. This Review describes the photosystem–electrode interface, as well as state-of-the-art electrode and biohybrid cell designs, and their importance in bio-photoelectrochemistry and semi-artificial photosynthesis.

Light can be used to power CO₂ conversion into value-added chemicals and fuels. In this Primer, Fang et al. provide a guide for the experimentation of photocatalytic CO₂ reduction, including catalyst synthesis and characterization, reactor construction, photocatalytic testing and exploration of mechanism.