Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Internal quantum efficiency higher than 100% achieved by combining doping and quantum effects for photocatalytic overall water splitting


Multiple exciton generation (MEG), where two or more electron–hole pairs are produced from the absorption of one high-energy photon, could increase the efficiency of light absorbing devices. However, demonstrations of the effect are still scarce in photocatalytic hydrogen production. Moreover, many photocatalytic systems for overall water splitting suffer from poor charge carrier separation. Here we show that a CdTe quantum dot/vanadium-doped indium sulphide (CdTe/V-In2S3) photocatalyst has a built-in electric field and cascade energy band structure sufficient to effectively extract excitons and separate carriers, allowing MEG to be exploited for hydrogen production. We achieve a tunable energy band structure through quantum effects in CdTe and doping engineering of V-In2S3, which induces a 14-fold enhancement in the CdTe/V-In2S3 interfacial built-in electric field intensity relative to pristine CdTe/V-In2S3. We report an internal quantum efficiency of 114% at 350 nm for photocatalytic hydrogen production, demonstrating the utilization of MEG effects. The solar-to-hydrogen efficiency is 1.31%.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Fig. 1: The energy band structures of the CdTe quantum dots and V-In2S3.
Fig. 2: The morphology and structure of the CdTe/V-In2S3 photocatalysts.
Fig. 3: The interfacial built-in electric field of the CdTe/V-In2S3 photocatalysts.
Fig. 4: The kinetics of interfacial carrier transport and the MEG effect of the CdTe/V-In2S3 photocatalysts.
Fig. 5: The photocatalytic performance of the CdTe/V-In2S3 photocatalysts.

Data availability

All data generated in this study are provided in the article, its Supplementary Information and the Source data provided with this paper.


  1. Liu, J. et al. Metal-free efficient photocatalyst for stable visible water splitting via a two-electron pathway. Science 347, 970–974 (2015).

    Article  Google Scholar 

  2. Wang, Q. et al. Scalable water splitting on particulate photocatalyst sheets with a solar-to-hydrogen energy conversion efficiency exceeding 1%. Nat. Mater. 15, 611–615 (2016).

    Article  Google Scholar 

  3. Zhao, D. et al. Boron-doped nitrogen-deficient carbon nitride-based Z-scheme heterostructures for photocatalytic overall water splitting. Nat. Energy 6, 388–397 (2021).

    Article  Google Scholar 

  4. Chen, X., Wang, J., Chai, Y., Zhang, Z. & Zhu, Y. Efficient photocatalytic overall water splitting induced by the giant internal electric field of a g-C3N4/rGO/PDIP Z-scheme heterojunction. Adv. Mater. 33, 2007479 (2021).

  5. Pan, Z., Zhang, G. & Wang, X. Polymeric carbon nitride/reduced graphene oxide/Fe2O3: all-solid-state Z-scheme system for photocatalytic overall water splitting. Angew. Chem. Int. Ed. 58, 7102–7106 (2019).

    Article  Google Scholar 

  6. Wang, Y. et al. Sulfur-deficient ZnIn2S4/oxygen-deficient WO3 hybrids with carbon layer bridges as a novel photothermal/photocatalytic integrated system for Z-scheme overall water splitting. Adv. Energy Mater. 11, 2102452 (2021).

    Article  Google Scholar 

  7. Chao, Y. et al. Ultrathin visible-light-driven Mo incorporating In2O3–ZnIn2Se4 Z-scheme nanosheet photocatalysts. Adv. Mater. 31, 1807226 (2019).

    Article  Google Scholar 

  8. Qi, Y. et al. Redox-based visible-light-driven Z-scheme overall water splitting with apparent quantum efficiency exceeding 10%. Joule 2, 2393–2402 (2018).

    Article  Google Scholar 

  9. Hirai, H. et al. Doping-mediated energy-level engineering of M@Au12 superatoms (M = Pd, Pt, Rh, Ir) for efficient photoluminescence and photocatalysis. Angew. Chem. Int. Ed. 61, e202207290 (2022).

    Google Scholar 

  10. Zhang, W. et al. High-performance photocatalytic nonoxidative conversion of methane to ethane and hydrogen by heteroatoms-engineered TiO2. Nat. Commun. 13, 2806 (2022).

    Article  Google Scholar 

  11. Takata, T. et al. Photocatalytic water splitting with a quantum efficiency of almost unity. Nature 581, 411–414 (2020).

    Article  Google Scholar 

  12. Song, X. et al. Overall photocatalytic water splitting by an organolead iodide crystalline material. Nat. Catal. 3, 1027–1033 (2020).

    Article  Google Scholar 

  13. Li, B. et al. In situ monitoring charge transfer on topotactic epitaxial heterointerface for tetracycline degradation at the single-particle level. ACS Catal. 12, 9114–9124 (2022).

    Article  Google Scholar 

  14. Jiang, W. et al. Tuning the anisotropic facet of lead chromate photocatalysts to promote spatial charge separation. Angew. Chem. Int. Ed. 61, e202207161 (2022).

    Article  Google Scholar 

  15. Shi, X. et al. Highly selective photocatalytic CO2 methanation with water vapor on single-atom platinum-decorated defective carbon nitride. Angew. Chem. Int. Ed. 61, e202203063 (2022).

    Google Scholar 

  16. Luo, L. et al. Synergy of Pd atoms and oxygen vacancies on In2O3 for methane conversion under visible light. Nat. Commun. 13, 2930 (2022).

    Article  Google Scholar 

  17. Wang, Z. et al. Overall water splitting by Ta3N5 nanorod single crystals grown on the edges of KTaO3 particles. Nat. Catal. 1, 756–763 (2018).

    Article  Google Scholar 

  18. Liu, F. et al. Direct Z-scheme hetero-phase junction of black/red phosphorus for photocatalytic water splitting. Angew. Chem. Int. Ed. 58, 11791–11795 (2019).

    Article  Google Scholar 

  19. Jiang, Z. et al. A hierarchical Z‑scheme α-Fe2O3/g-C3N4 hybrid for enhanced photocatalytic CO2 reduction. Adv. Mater. 30, 1706108 (2018).

    Article  Google Scholar 

  20. Maeda, K. Z-scheme water splitting using two different semiconductor photocatalysts. ACS Catal. 3, 1486–1503 (2013).

    Article  Google Scholar 

  21. Wang, J. et al. Porphyrin conjugated polymer grafted onto BiVO4 nanosheets for efficient Z-scheme overall water splitting via cascade charge transfer and single-atom catalytic sites. Adv. Energy Mater. 11, 2003575 (2021).

    Article  Google Scholar 

  22. Li, H. et al. New reaction pathway induced by plasmon for selective benzyl alcohol oxidation on BiOCl possessing oxygen vacancies. J. Am. Chem. Soc. 139, 3513–3521 (2017).

    Article  Google Scholar 

  23. Low, J., Dai, B., Tong, T., Jiang, C. & Yu, J. In situ irradiated X-ray photoelectron spectroscopy investigation on a direct Z-scheme TiO2/CdS composite film photocatalyst. Adv. Mater. 31, 1802981 (2019).

  24. Chen, X. et al. Three-dimensional porous g-C3N4 for highly efficient photocatalytic overall water splitting. Nano Energy 59, 644–650 (2019).

    Article  Google Scholar 

  25. Oshima, T. et al. An artificial Z-scheme constructed from dye-sensitized metal oxide nanosheets for visible light-driven overall water splitting. J. Am. Chem. Soc. 142, 8412–8420 (2020).

    Article  Google Scholar 

  26. Wang, L., Zheng, X., Chen, L., Xiong, Y. & Xu, H. van der Waals heterostructures comprised of ultrathin polymer nanosheets for efficient Z-scheme overall water splitting. Angew. Chem. Int. Ed. 57, 3454–3458 (2018).

  27. Sun, S. et al. Efficient redox-mediator-free Z-scheme water splitting employing oxysulfide photocatalysts under visible light. ACS Catal. 8, 1690–1696 (2018).

    Article  Google Scholar 

  28. Chen, Y. et al. Multiple exciton generation in tin–lead halide perovskite nanocrystals for photocurrent quantum efficiency enhancement. Nat. Photon. 16, 485–490 (2022).

  29. Sambur, J. B., Novet, T. & Parkinson, B. A. Multiple exciton collection in a sensitized photovoltaic system. Science 330, 63–66 (2010).

  30. Sukhovatkin, V., Hinds, S., Brzozowski, L. & Sargent, E. H. Colloidal quantum-dot photodetectors exploiting multiexciton generation. Science 324, 1542–1544 (2009).

  31. Semonin, O. E. et al. Peak external photocurrent quantum efficiency exceeding 100% via MEG in a quantum dot solar Cell. Science 334, 1530–1533 (2011).

    Article  Google Scholar 

  32. Yan, Y. et al. Multiple exciton generation for photoelectrochemical hydrogen evolution reactions with quantum yields exceeding 100%. Nat. Energy 2, 17052 (2017).

  33. Liu, X. et al. Activating the electrocatalysis of MoS2 basal plane for hydrogen evolution via atomic defect configurations. Small 18, e2200601 (2022).

  34. Ye, Z., Li, T., Ma, G., Dong, Y. & Zhou, X. Metal-ion (Fe, V, Co, and Ni)-doped MnO2 ultrathin nanosheets supported on carbon fiber paper for the oxygen evolution reaction. Adv. Funct. Mater. 27, 1704083 (2017).

  35. He, P. et al. Layered VS2 nanosheet-based aqueous Zn ion battery cathode. Adv. Energy Mater. 7, 1601920 (2017).

  36. Lei, F. et al. Atomic-layer-confined doping for atomic-level insights into visible-light water splitting. Angew. Chem. Int. Ed. 54, 9266–9270 (2015).

    Article  Google Scholar 

  37. Mak, J. S. W., Farah, A. A., Chen, F. & Helmy, A. S. Photonic crystal fiber for efficient raman scattering of CdTe quantum dots in aqueous solution. ACS Nano 5, 3823–3830 (2011).

  38. Bajorowicz, B., Nadolna, J., Lisowski, W., Klimczuk, T. & Zaleska-Medynska, A. The effects of bifunctional linker and reflux time on the surface properties and photocatalytic activity of CdTe quantum dots decorated KTaO3 composite photocatalysts. Appl. Catal. B 203, 452–464 (2017).

  39. Wang, B. et al. Heat diffusion-induced gradient energy level in multishell bisulfides for highly efficient photocatalytic hydrogen production. Adv. Energy Mater. 10, 2001575 (2020).

    Article  Google Scholar 

  40. Ling, C. et al. Atomic-layered Cu5 nanoclusters on FeS2 with dual catalytic sites for efficient and selective H2O2 activation. Angew. Chem. Int. Ed. 61, e202200670 (2022).

    Article  Google Scholar 

  41. Zhang, P. et al. Photogenerated electron transfer process in heterojunctions: in situ irradiation XPS. Small Methods 4, 2000214 (2020).

  42. Zhang, Z., Nagashima, H. & Tachikawa, T. Ultra-narrow depletion layers in a hematite mesocrystal-based photoanode for boosting multihole water oxidation. Angew. Chem. Int. Ed. 59, 9047–9054 (2020).

  43. Li, C. et al. Surviving high-temperature calcination: ZrO2-induced hematite nanotubes for photoelectrochemical water oxidation. Angew. Chem. Int. Ed. 56, 4150–4155 (2017).

    Article  Google Scholar 

  44. Han, T. et al. Anion-exchange-mediated internal electric field for boosting photogenerated carrier separation and utilization. Nat. Commun. 12, 4952 (2021).

    Article  Google Scholar 

  45. Li, J., Cai, L., Shang, J., Yu, Y. & Zhang, L. Giant enhancement of internal electric field boosting bulk charge separation for photocatalysis. Adv. Mater. 28, 4059–4064 (2016).

  46. Kroupa, D. M. et al. Enhanced multiple exciton generation in PbS|CdS Janus-like heterostructured nanocrystals. ACS Nano 12, 10084–10094 (2018).

    Article  Google Scholar 

  47. He, Y. et al. 3D hierarchical ZnIn2S4 nanosheets with rich Zn vacancies boosting photocatalytic CO2 reduction. Adv. Funct. Mater. 29, 1905153 (2019).

    Article  Google Scholar 

  48. Sun, S. et al. Engineering interfacial band bending over bismuth vanadate/carbon nitride by work function regulation for efficient solar-driven water splitting. Sci. Bull. 67, 389–397 (2022).

    Article  Google Scholar 

  49. Sun, X. et al. Enhanced superoxide generation on defective surfaces for selective photooxidation. J. Am. Chem. Soc. 141, 3797 (2019).

    Article  Google Scholar 

  50. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).

  51. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

  52. Grimme, S., Ehrlich, S. & Goerigk, L. Effect of the damping function in dispersion corrected density functional theory. J. Comput. Chem. 32, 1456–1465 (2011).

  53. Neugebauer, J. & Scheffler, M. Adsorbate–substrate and adsorbate–adsorbate interactions of Na and K adlayers on Al(111). Phys. Rev. B 46, 16067–16080 (1992).

Download references


This research is supported by the National Natural Science Foundation of China (22261142666, 52172237), the Shaanxi Science Fund for Distinguished Young Scholars (2022JC-21), the Research Fund of the State Key Laboratory of Solidification Processing (NPU), China (grant no. 2021-QZ-02) and the Fundamental Research Funds for the Central Universities (3102019JC005, D5000220033). All funds were awarded to X.L. We thank the members of the Analytical and Testing Center of Northwestern Polytechnical University for help with X-ray diffraction, XPS and SEM characterization.

Author information

Authors and Affiliations



X.L. and Y.Z. proposed the experimental concepts, designed the experiments and prepared the paper. X.L. supervised the project. Y.Z., X.X., Y.W., P.G., R.W. and B.W. carried out the experiments and conducted the materials characterization. W.H. and A.J.S. revised the paper. Y.L. finished the computation. All authors discussed the results and approved the final version of the paper.

Corresponding author

Correspondence to Xuanhua Li.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Energy thanks the anonymous reviewers for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–49, Discussion, Tables 1–8 and Notes 1 and 2.

Source data

Source Data Fig. 3

Source data for Fig. 3e,f.

Source Data Fig. 4

Source data for averages and error bars in Fig. 4b,c.

Source Data Fig. 5

Source data for averages and error bars in Fig. 5d.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhang, Y., Li, Y., Xin, X. et al. Internal quantum efficiency higher than 100% achieved by combining doping and quantum effects for photocatalytic overall water splitting. Nat Energy 8, 504–514 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing