Solar-driven reforming of lignocellulose to H2 with a CdS/CdOx photocatalyst


Lignocellulose is Earth’s most abundant form of biomass and its valorization to H2 is a key objective for the generation of renewable fuels. Solar-driven photocatalytic reforming of lignocellulose to H2 at ambient temperature offers a sustainable route towards this goal, but this reaction is currently limited to noble-metal-containing systems that operate with low activity under ultraviolet light. Here, we report the light-driven photoreforming of cellulose, hemicellulose and lignin to H2 using semiconducting cadmium sulfide quantum dots in alkaline aqueous solution. We show that basic conditions cause these dots to become coated with oxide/hydroxide in situ, presenting a strategy to improve their photocatalytic performance. The system operates under visible light, is stable beyond six days and is even able to reform unprocessed lignocellulose, such as wood and paper, under solar irradiation at room temperature, presenting an inexpensive route to drive aqueous proton reduction to H2 through waste biomass oxidation.

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Figure 1: Photoreforming of lignocellulose to H2 on CdS/CdOx.
Figure 2: Characterization of CdS/CdOx.
Figure 3: Photoreforming of cellulose to H2 using CdS/CdOx.
Figure 4: The rate of H2 generation through photoreforming lignocellulose on CdS/CdOx.


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This work was supported by the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and the National Foundation for Research, Technology and Development), the OMV Group (to E.R.), the EPSRC (DTA studentships for D.W.W. and T.E.R), the Isaac Newton Trust, the German Research Foundation (to M.F.K.), the World Premier Institute Research Center Initiative (WPI), MEXT, Japan (to K.L.O.) and a Marie Curie Research fellowship (to K.H.L., GAN 701192 - VSHER). We would like to thank Mr Adam Brown (Cambridge, UK) for performing XPS measurements, Prof. Peter Hildebrandt (TU Berlin, Germany) for providing access to his laboratory to record Raman spectra and Dr Benjamin Martindale for proofreading this manuscript.

Author information




D.W.W., M.F.K. and E.R. conceived the research. D.W.W. and M.F.K. performed photocatalysis and NMR experiments. D.W.W. and K.L.O. synthesized and characterized the QDs. K.L.O. executed TEM, XRD and the zeta potential analysis. K.H.L. carried out the Raman experiments. D.W.W. and T.E.R. carried out the fluorescence measurements. All authors analysed the data. D.W.W. wrote the manuscript. M.F.K., K.H.L. and E.R. added to the discussion and contributed to the preparation of the manuscript. E.R. supervised the work.

Corresponding author

Correspondence to Erwin Reisner.

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Competing interests

Patent applications covering this work have been filed by Cambridge Enterprise (UK patent application numbers GB1619953.1 and GB1701130.5) that name D.W.W., M.F.K., K.L.O. and E.R. as inventors.

Supplementary information

Supplementary Information

Supplementary Tables 1–10, Supplementary Figures 1–14. (PDF 1688 kb)

Supplementary Video 1

Video of the reported system evolving H2 in the presence of a cutting from a wooden branch or paper. 3.6 nmol of ligand-free CdS QDs in DMF are injected onto each substrate and dried. The substrate was then added to 2 ml of 10 M KOH, forming CdS/CdOx. Samples were purged with N2 and irradiated using simulated solar light (AM 1.5G, 100 mW cm−2) for 1 h before filming. Filming was undertaken while irradiating with light from a nearby Kodak carousel 2020 projector. (MP4 116522 kb)

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Wakerley, D., Kuehnel, M., Orchard, K. et al. Solar-driven reforming of lignocellulose to H2 with a CdS/CdOx photocatalyst. Nat Energy 2, 17021 (2017).

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