Pt Sub-Nanoclusters on ZIF-Derived Ultrafine Cd_xZn_1−xS Solid Solution: High-Performance Photoreforming Lactic Acid to H₂ and Value-Added Chemicals

Abstract

Solar-driven H₂ production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals, yet its feasibility relies critically on effective bifunctional photocatalysts. Herein, we report the synthesis of ultrafine Cd_xZn_1−xS nanocrystals derived from a zeolitic imidazolate framework (ZIF), featuring high surface area, shortened charge diffusion path, and enhanced H₂ evolution activity. Anchoring amorphous Pt sub-nanoclusters onto these nanocrystals created a bifunctional catalyst (Pt-Cd_xZn_1−xS) for efficient lactic acid photoreforming, enabling co-production of H₂ with switchable selectivity toward pyruvic acid (PA) or 2,3-dihydroxy-2,3- dimethylsuccinic acid (DTA). The optimized 0.5Pt-Cd_0.3Zn_0.7S catalyst achieved an exceptional H₂ production rate of 270.6 mmol h⁻¹ g⁻¹, 73.1% PA selectivity, and 62.8% apparent quantum efficiency at 400 nm. Mechanistic studies revealed that lactic acid undergoes C-H cleavage to form carbon-centered radicals. Pt sub-nanoclusters served as electron sinks to facilitate O-H dissociation and PA formation, whereas pristine Cd_0.3Zn_0.67S promoted direct C-C coupling of radicals to predominantly yield DTA. This work offers critical insights for designing advanced bifunctional photocatalysts to integrate solar hydrogen and value-added chemical synthesis.

Keywords

bifunctional photocatalysts / hydrogen / nanocluster / photocatalysis / value-added chemical synthesis

References

[1] Q. Wang and K. Domen, “Particulate Photocatalysts for Light-Driven Water Splitting: Mechanisms, Challenges, and Design Strategies,” Chemical Reviews 120, no. 2 (2019): 919–985, https://doi.org/10.1021/acs.chemrev.9b00201.

[2] X. Chu, C. I. Sathish, J.-H. Yang, et al., “Sodium Chloride-Assisted Crystalline Graphitic Carbon Nitride for Efficient Photocatalytic Hydrogen Evolution,” Electron 3, no. 2 (2025): e70000, https://doi.org/10.1002/elt2.70000.

[3] P. Zhou, I. A. Navid, Y. Ma, et al., “Solar-To-Hydrogen Efficiency of More Than 9% in Photocatalytic Water Splitting,” Nature 613, no. 7942 (2023): 66–70, https://doi.org/10.1038/s41586-022-05399-1.

[4] X. Chen, S. Shen, L. Guo, and S. S. Mao, “Semiconductor-Based Photocatalytic Hydrogen Generation,” Chemical Reviews 110, no. 11 (2010): 6503–6570, https://doi.org/10.1021/cr1001645.

[5] M. Han, M. Han, J. Ma, M. Du, Q. Zhu, and B. Qiu, “Photocatalytic Upcycling of Plastic Waste Into Value-Added Chemicals,” Electron 3, no. 2 (2025): e70005, https://doi.org/10.1002/elt2.70005.

[6] N. Luo, T. Montini, J. Zhang, et al., “Visible-Light-Driven Coproduction of Diesel Precursors and Hydrogen From Lignocellulose-Derived Methylfurans,” Nature Energy 4, no. 7 (2019): 575–584, https://doi.org/10.1038/s41560-019-0403-5.

[7] M.-Y. Qi, Y.-H. Li, M. Anpo, Z.-R. Tang, and Y.-J. Xu, “Efficient Photoredox-Mediated C–C Coupling Organic Synthesis and Hydrogen Production Over Engineered Semiconductor Quantum Dots,” ACS Catalysis 10, no. 23 (2020): 14327–14335, https://doi.org/10.1021/acscatal.0c04237.

[8] M.-Y. Qi, M. Conte, M. Anpo, Z.-R. Tang, and Y.-J. Xu, “Cooperative Coupling of Oxidative Organic Synthesis and Hydrogen Production Over Semiconductor-Based Photocatalysts,” Chemical Reviews 121, no. 21 (2021): 13051–13085, https://doi.org/10.1021/acs.chemrev.1c00197.

[9] B. Liu, Z. Hu, Y. Li, X. Tan, J. Ye, and T. Yu, “Simultaneous Value-Added Utilization of Photogenerated Electrons and Holes on Pd/TiO₂,” Nature Communications 16, no. 1 (2025): 6014, https://doi.org/10.1038/s41467-025-61223-0.

[10] Q. Li, B. Guo, J. Yu, et al., “Highly Efficient Visible-Light- Driven Photocatalytic Hydrogen Production of CdS-Cluster-Decorated Graphene Nanosheets,” Journal of the American Chemical Society 133, no. 28 (2011): 10878–10884, https://doi.org/10.1021/ja2025454.

[11] X. Zong, H. Yan, G. Wu, et al., “Enhancement of Photocatalytic H₂ Evolution on CdS by Loading MoS₂ as Cocatalyst Under Visible Light Irradiation,” Journal of the American Chemical Society 130, no. 23 (2008): 7176–7177, https://doi.org/10.1021/ja8007825.

[12] Y. Guo, J. Sun, Z. Geng, et al., “Reinforced Interfacial Cd-Se Bond Coupling Photocatalytic Hydrogen Evolution With Pyruvic Acid Synthesis,” Advanced Energy Materials 14, no. 32 (2024): 2401285, https://doi.org/10.1002/aenm.202401285.

[13] C. Bie, B. Zhu, L. Wang, et al., “A Bifunctional CdS/MoO₂/MoS₂ Catalyst Enhances Photocatalytic H₂ Evolution and Pyruvic Acid Synthesis,” Angewandte Chemie International Edition 134, no. 44 (2022): e202212045, https://doi.org/10.1002/anie.202212045.

[14] Y. You, P. Han, S. Song, et al., “Distinct Selectivity Control in Solar-Driven Bio-Based α-Hydroxyl Acid Conversion: A Comparison of Pt Nanoparticles and Atomically Dispersed Pt on CdS,” Angewandte Chemie International Edition 62, no. 43 (2023): e202306452, https://doi.org/10.1002/anie.202306452.

[15] F. Liu, F. Xue, Y. Si, et al., “Functionalized Cd_0.5Zn_0.5S Chalcogenide Nanotwins Enabling Z-Scheme Photocatalytic Water Splitting,” ACS Applied Nano Materials 4, no. 1 (2021): 759–768, https://doi.org/10.1021/acsanm.0c03054.

[16] F. Liu, Y. Fu, K. Lu, et al., “Solar Reforming Lignocellulose Into H₂ Over PH-Triggered Hydroxyl-Functionalized Chalcogenide Nanotwins,” ACS Catalysis 13, no. 23 (2023): 15591–15602, https://doi.org/10.1021/acscatal.3c03786.

[17] X. Wu, S. Xie, H. Zhang, Q. Zhang, B. F. Sels, and Y. Wang, “Metal Sulfide Photocatalysts for Lignocellulose Valorization,” Advanced Materials 33, no. 50 (2021): 2007129, https://doi.org/10.1002/adma.202007129.

[18] L.-J. Gao, L. Chen, J.-T. Ren, C.-C. Weng, W.-W. Tian, and Z.-Y. Yuan, “Mesoporous Cd_xZn_1-xS With Abundant Surface Defects for Efficient Photocatalytic Hydrogen Production,” Journal of Colloid and Interface Science 589 (2021): 25–33, https://doi.org/10.1016/j.jcis.2020.12.112.

[19] S. Chen, Y. Qi, C. Li, K. Domen, and F. Zhang, “Surface Strategies for Particulate Photocatalysts Toward Artificial Photosynthesis,” Joule 2, no. 11 (2018): 2260–2288, https://doi.org/10.1016/j.joule.2018.07.030.

[20] M. A. Panhwar, B. Guene Lougou, M. Rafique, et al., “Synergistic Co-Catalyst Strategies for Photo-Thermal CO₂ Reduction Into Value-Added Fuels: A Critical Review on Mechanisms, Challenges, and Future Prospects,” Fuel 400 (2025): 135729, https://doi.org/10.1016/j.fuel.2025.135729.

[21] L. Gloag, S. V. Somerville, J. J. Gooding, and R. D. Tilley, “Co-Catalytic Metal–Support Interactions in Single-Atom Electrocatalysts,” Nature Review Materials 9, no. 3 (2024): 173–189, https://doi.org/10.1038/s41578-023-00633-2.

[22] D. V. Markovskaya, A. V. Zhurenok, S. V. Cherepanova, and E. A. Kozlova, “Solid Solutions of CdS and ZnS: Comparing Photocatalytic Activity and Photocurrent Generation,” Applied Surface Science Advances 4 (2021): 100076, https://doi.org/10.1016/j.apsadv.2021.100076.

[23] L. Cheng, Q. Xiang, Y. Liao, and H. Zhang, “CdS-Based Photocatalysts,” Energy & Environmental Science 11, no. 6 (2018): 1362–1391, https://doi.org/10.1039/c7ee03640j.

[24] Z. Liu, D. Sun, C. Wang, et al., “Zeolitic Imidazolate Framework-67 and Its Derivatives for Photocatalytic Applications,” Coordination Chemistry Reviews 502 (2024): 215612, https://doi.org/10.1016/j.ccr.2023.215612.

[25] W. Li, W. Kang, T. Zhou, N. Wu, and H. Pang, “Synthesis and Structure–Activity Relationship of Porous Coordination Polymers and Their Composites as Photocatalysts Environmental Remediation,”Electron 3, no. 2 (2025): e70002, https://doi.org/10.1002/elt2.70002.

[26] K. J. Nam, A. M. O. Mohamed, J. Seong, et al., “Cobalt-Based ZIF Composite Membranes: In Situ Defect Engineering for Enhanced Water Stability and Gas Separation,” Small 21, no. 19 (2025): 2409515, https://doi.org/10.1002/smll.202409515.

[27] Z. Liu, Z. Chen, M. Li, et al., “Construction of Single Ni Atom-Immobilized ZIF-8 With Ordered Hierarchical Pore Structures for Selective CO₂ Photoreduction,” ACS Catalysis 13, no. 10 (2023): 6630–6640, https://doi.org/10.1021/acscatal.3c01118.

[28] X. Zhang, S. Wang, Z. Sun, et al., “Tailoring the d- Band Electronic Structure of FePc by Direct Oxygen Bridge on ZIF-8 Derived Ultrathin Carbon Shell to Improve the Oxygen Reduction Performance,” Nano Research 18, no. 3 (2025): 94907235, https://doi.org/10.26599/nr.2025.94907235.

[29] M. Liu, D. Jing, Z. Zhou, and L. Guo, “Twin-Induced One-Dimensional Homojunctions Yield High Quantum Efficiency for Solar Hydrogen Generation,” Nature Communications 4 (2013): 1–8, https://doi.org/10.1038/ncomms3278.

[30] M. Liu, Y. Chen, J. Su, J. Shi, X. Wang, and L. Guo, “Photocatalytic Hydrogen Production Using Twinned Nanocrystals and an Unanchored NiS_x Co-Catalyst,” Nature Energy 1, no. 11 (2016): 1–8, https://doi.org/10.1038/nenergy.2016.151.

[31] U. Venkateswaran, M. Chandrasekhar, and H. R. Chandrasekhar, “Luminescence and Raman Spectra of CdS Under Hydrostatic Pressure,” Physical Review B: Condensed Matter 30, no. 6 (1984): 3316–3319, https://doi.org/10.1103/physrevb.30.3316.

[32] H. Zhang, X. Ma, J. Xu, J. Niu, J. Sha, and D. Yang, “Directional CdS Nanowires Fabricated by Chemical Bath Deposition,” Journal of Crystal Growth 246, no. 1–2 (2002): 108–112, https://doi.org/10.1016/s0022-0248(02)01900-0.

[33] Y. Zhang, S. Wang, Y. Yang, et al., “A Switchable Hydrogenation Chemoselectivity of Biomass Platform Compounds Based on Solvent Regulation,” Applied Catalysis B: Environment and Energy 346 (2024): 123719, https://doi.org/10.1016/j.apcatb.2024.123719.

[34] Y. Si, Y. Jiao, M. Wang, et al., “Fully Exposed Pt Clusters for Efficient Catalysis of Multi-Step Hydrogenation Reactions,” Nature Communications 15, no. 1 (2024): 4887, https://doi.org/10.1038/s41467-024-49083-6.

[35] Y. Huang, D. Ma, W. Liu, et al., “Enhanced Catalytic Ozonation for Eliminating CH₃SH via Graphene-Supported Positively Charged Atomic Pt Undergoing Pt²⁺/Pt⁴⁺ Redox Cycle,” Environmental Science and Technology 55, no. 24 (2021): 16723–16734, https://doi.org/10.1021/acs.est.1c06938.

[36] J. Kou, J. Zhu Chen, J. Gao, et al., “Structural and Catalytic Properties of Isolated Pt²⁺ Sites in Platinum Phosphide (PtP₂),” ACS Catalysis 11, no. 21 (2021): 13496–13509, https://doi.org/10.1021/acscatal.1c03970.

[37] J. Fregoni, T. S. Haugland, S. Pipolo, T. Giovannini, H. Koch, and S. Corni, “Strong Coupling Between Localized Surface Plasmons and Molecules by Coupled Cluster Theory,” Nano Letters 21, no. 15 (2021): 6664–6670, https://doi.org/10.1021/acs.nanolett.1c02162.

[38] S. K. Filippov, R. Khusnutdinov, A. Murmiliuk, et al., “Dynamic Light Scattering and Transmission Electron Microscopy in Drug Delivery: A Roadmap for Correct Characterization of Nanoparticles and Interpretation of Results,” Materials Horizons 10, no. 12 (2023): 5354–5370, https://doi.org/10.1039/d3mh00717k.

[39] X. Wang, B. Yin, L. Jiang, et al., “Ligand-Protected Metal Nanoclusters as Low-Loss, Highly Polarized Emitters for Optical Waveguides,” Science 381, no. 6659 (2023): 784–790, https://doi.org/10.1126/science.adh2365.

[40] J. Ma, T. J. Miao, and J. Tang, “Charge Carrier Dynamics and Reaction Intermediates in Heterogeneous Photocatalysis by Time-Resolved Spectroscopies,” Chemical Society Reviews 51, no. 14 (2022): 5777–5794, https://doi.org/10.1039/d1cs01164b.

[41] C. Bie, B. Zhu, L. Wang, et al., “A Bifunctional CdS/MoO₂/MoS₂ Catalyst Enhances Photocatalytic H₂ Evolution and Pyruvic Acid Synthesis,” Angewandte Chemie International Edition 61, no. 44 (2022): e202212045, https://doi.org/10.1002/ange.202212045.

[42] F. Xue, Y. Si, M. Wang, M. Liu, and L. Guo, “Toward Efficient Photocatalytic Pure Water Splitting for Simultaneous H₂ and H₂O₂ Production,” Nano Energy 62 (2019): 823–831, https://doi.org/10.1016/j.nanoen.2019.05.086.

[43] M. Chai, F.-Q. Wang, and D.-Z. Wei, “Synthesis of Organic Acids From Lignocellulose by Biotransformation,” Synthetic Biology Journal (2024): 1, https://synbioj.cip.com.cn/CN/10.12211/2096-8280.2024-011.

[44] X. Li, J. Yu, J. Low, Y. Fang, J. Xiao, and X. Chen, “Engineering Heterogeneous Semiconductors for Solar Water Splitting,” Journal of Materials Chemistry A 3, no. 6 (2015): 2485–2534, https://doi.org/10.1039/c4ta04461d.

[45] J. Fang, T. Debnath, S. Bhattacharyya, M. Döblinger, J. Feldmann, and J. K. Stolarczyk, “Photobase Effect for Just-in-Time Delivery in Photocatalytic Hydrogen Generation,” Nature Communications 11 (2020): 1–8, https://doi.org/10.1038/s41467-020-18583-6.

[46] Y. Guo, Q. Zhou, J. Nan, W. Shi, F. Cui, and Y. Zhu, “Perylenetetracarboxylic Acid Nanosheets With Internal Electric Fields and Anisotropic Charge Migration for Photocatalytic Hydrogen Evolution,” Nature Communications 13 (2022): 1–10, https://doi.org/10.1038/s41467-022-29826-z.

[47] Y. Miao, Y. Zhao, J. Gao, J. Wang, and T. Zhang, “Direct Photoreforming of Real-World Polylactic Acid Plastics Into Highly Selective Value-Added Pyruvic Acid Under Visible Light,” Journal of the American Chemical Society 146, no. 7 (2024): 4842–4850, https://doi.org/10.1021/jacs.3c13000.

[48] S. Xie, Z. Shen, J. Deng, et al., “Visible Light-Driven C−H Activation and C–C Coupling of Methanol Into Ethylene Glycol,” Nature Communications 9, no. 1 (2018): 1181, https://doi.org/10.1038/s41467-018-03543-y.

[49] F. Liu, C. Zhang, K. Lu, et al., “Pilot-Scale Photoreforming of Hydrolyzed Polylactic Acid Waste to High-Value Chemicals and H₂ via Atomic Ru Integration,” Advanced Energy Materials 15, no. 26 (2025): 2500015, https://doi.org/10.1002/aenm.202500015.

RIGHTS & PERMISSIONS

2025 The Author(s). Electron published by Harbin Institute of Technology and John Wiley & Sons Australia, Ltd.