Solar panels are well known to produce electricity, but they are also in early-stage development for the production of sustainable fuels and chemicals. These panels mimic plant leaves in shape and function as demonstrated for overall solar water splitting to produce green hydrogen.^1,2 This presentation will give an overview of our progress to construct prototype solar panel devices for the direct conversion of carbon dioxide and solid waste streams into fuels and higher-value chemicals through molecular surface-engineering of solar panels with catalysts. Specifically, a standalone ‘photoelectrochemical leaf’ based on an integrated lead halide perovskite-BiVO₄ tandem light absorber architecture has been constructed for the solar CO₂ reduction to produce syngas (CO and H₂).³ Further manufacturing advances have enabled the reduction of material requirements to fabricate such devices and make the leaves sufficiently light weight to float on water, thereby enabling application on open water sources.⁴ The tandem design also allows for the integration of biocatalysts and the selective and bias-free conversion of CO₂-to-formate has been demonstrated using enzymes.⁵ Recent progress in catalyst-development has allowed us to demonstrate carbon-carbon bond formation and the direct production of liquid multicarbon alcohol fuels directly from CO₂.⁶ The versatility of the integrated leaf architecture has been shown by replacing the perovskite light absorber by BiOI for solar water and CO₂ splitting with week-long stability.⁷

An alternative solar carbon capture and utilisation technology is based on co-deposited semiconductor powders on a conducting substrate.² Modification of these immobilized powders with a molecular catalyst provides us with a photocatalyst sheet that can cleanly produce formic acid from aqueous CO₂.⁸ CO₂-fixing bacteria grown on such photocatalyst sheets enable the production of multicarbon products through clean CO₂-to-acetate conversion.⁹ The deposition of a single semiconductor material on glass gives panels for the sunlight-powered conversion plastic and biomass waste into hydrogen and organic products, thereby allowing for simultaneous waste remediation and fuel production.^10,11 The concept and prospect behind these integrated systems for solar energy conversion,¹² related approaches,¹³ and their relevance to secure and harness sustainable energy supplies in a fossil-fuel free economy will be discussed.

References

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[2] Wang et al., Nat. Mater., 2016, 15, 611–615

[3] Andrei et al., Nat. Mater., 2020, 19, 189–194

[4] Andrei et al., Nature, 2022, 608, 518–522

[5] Moore et al., Angew. Chem. Int. Ed., 2021, 60, 26303–26307

[6] Rahaman et al., Nat. Energy, 2023, 8, 629–638

[7] Andrei et al., Nat. Mater., 2022, 21, 864–868

[8] Wang et al., Nat. Energy, 2020, 5, 703–710

[9] Wang et al., Nat. Catal., 2022, 5, 633–641

[10] Uekert et al., Nat. Sustain., 2021, 4, 383–391

[11] Bhattacharjee et al., Nat. Synth., 2023, 2, 182–192

[12] Andrei et al., Acc. Chem. Res., 2022, 55, 3376–3386

[13] Wang et al., Nat. Energy, 2022, 7, 13–24