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%.
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Liu, J. et al. Metal-free efficient photocatalyst for stable visible water splitting via a two-electron pathway. Science 347, 970–974 (2015).
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).
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).
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).
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).
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).
Chao, Y. et al. Ultrathin visible-light-driven Mo incorporating In2O3–ZnIn2Se4 Z-scheme nanosheet photocatalysts. Adv. Mater. 31, 1807226 (2019).
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).
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).
Zhang, W. et al. High-performance photocatalytic nonoxidative conversion of methane to ethane and hydrogen by heteroatoms-engineered TiO2. Nat. Commun. 13, 2806 (2022).
Takata, T. et al. Photocatalytic water splitting with a quantum efficiency of almost unity. Nature 581, 411–414 (2020).
Song, X. et al. Overall photocatalytic water splitting by an organolead iodide crystalline material. Nat. Catal. 3, 1027–1033 (2020).
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).
Jiang, W. et al. Tuning the anisotropic facet of lead chromate photocatalysts to promote spatial charge separation. Angew. Chem. Int. Ed. 61, e202207161 (2022).
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).
Luo, L. et al. Synergy of Pd atoms and oxygen vacancies on In2O3 for methane conversion under visible light. Nat. Commun. 13, 2930 (2022).
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).
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).
Jiang, Z. et al. A hierarchical Z‑scheme α-Fe2O3/g-C3N4 hybrid for enhanced photocatalytic CO2 reduction. Adv. Mater. 30, 1706108 (2018).
Maeda, K. Z-scheme water splitting using two different semiconductor photocatalysts. ACS Catal. 3, 1486–1503 (2013).
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).
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).
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).
Chen, X. et al. Three-dimensional porous g-C3N4 for highly efficient photocatalytic overall water splitting. Nano Energy 59, 644–650 (2019).
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).
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).
Sun, S. et al. Efficient redox-mediator-free Z-scheme water splitting employing oxysulfide photocatalysts under visible light. ACS Catal. 8, 1690–1696 (2018).
Chen, Y. et al. Multiple exciton generation in tin–lead halide perovskite nanocrystals for photocurrent quantum efficiency enhancement. Nat. Photon. 16, 485–490 (2022).
Sambur, J. B., Novet, T. & Parkinson, B. A. Multiple exciton collection in a sensitized photovoltaic system. Science 330, 63–66 (2010).
Sukhovatkin, V., Hinds, S., Brzozowski, L. & Sargent, E. H. Colloidal quantum-dot photodetectors exploiting multiexciton generation. Science 324, 1542–1544 (2009).
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).
Yan, Y. et al. Multiple exciton generation for photoelectrochemical hydrogen evolution reactions with quantum yields exceeding 100%. Nat. Energy 2, 17052 (2017).
Liu, X. et al. Activating the electrocatalysis of MoS2 basal plane for hydrogen evolution via atomic defect configurations. Small 18, e2200601 (2022).
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).
He, P. et al. Layered VS2 nanosheet-based aqueous Zn ion battery cathode. Adv. Energy Mater. 7, 1601920 (2017).
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).
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).
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).
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).
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).
Zhang, P. et al. Photogenerated electron transfer process in heterojunctions: in situ irradiation XPS. Small Methods 4, 2000214 (2020).
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).
Li, C. et al. Surviving high-temperature calcination: ZrO2-induced hematite nanotubes for photoelectrochemical water oxidation. Angew. Chem. Int. Ed. 56, 4150–4155 (2017).
Han, T. et al. Anion-exchange-mediated internal electric field for boosting photogenerated carrier separation and utilization. Nat. Commun. 12, 4952 (2021).
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).
Kroupa, D. M. et al. Enhanced multiple exciton generation in PbS|CdS Janus-like heterostructured nanocrystals. ACS Nano 12, 10084–10094 (2018).
He, Y. et al. 3D hierarchical ZnIn2S4 nanosheets with rich Zn vacancies boosting photocatalytic CO2 reduction. Adv. Funct. Mater. 29, 1905153 (2019).
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).
Sun, X. et al. Enhanced superoxide generation on defective surfaces for selective photooxidation. J. Am. Chem. Soc. 141, 3797 (2019).
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).
Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).
Grimme, S., Ehrlich, S. & Goerigk, L. Effect of the damping function in dispersion corrected density functional theory. J. Comput. Chem. 32, 1456–1465 (2011).
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).
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.
The authors declare no competing interests.
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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.
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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). https://doi.org/10.1038/s41560-023-01242-7
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