Solar-driven plastic waste conversion: A mini-review on photoreforming for Co-producing hydrogen and chemical feedstocks

Abstract

The increasing accumulation of discarded plastics has already caused serious environmental pollution. Simple landfills and incineration will inevitably lead to the loss of the abundant carbon resources contained in plastic waste. In contrast, photoconversion technology provides a green and sustainable solution to the global plastic waste crisis by converting plastics into hydrogen fuel and valuable chemicals. This review briefly introduces the advantages of photoconversion technology and highlights recent research progress, with a focus on photocatalyst design as well as the thermodynamics and kinetics of the reaction process. It discusses in detail the degradation of typical common plastic types into hydrogen and fine chemicals via photoconversion. Additionally, it outlines future research directions, including the application of artificial intelligence in catalyst design. Although photocatalytic technology remains at the laboratory stage, with challenges in catalyst performance and industrial scalability, the potential for renewable energy generation and plastic valorization is promising.

Graphical abstract

Keywords

photoreforming / waste plastics / hydrogen production / chemical feedstock / photocatalysts

References

[1] Son S , Haider Z , Lee D Y . . Ambivalent photocatalytic strategies for plastic waste conversion: Alkalinized carbon nitride for H₂O₂ production and complete mineralization. Applied Catalysis B: Environmental, 2025, 365: 124847

[2] Talebian-Kiakalaieh A , Li H , Guo M . . Photocatalytic reforming raw plastic in seawater by atomically-engineered GeS/ZnIn₂S₄. Advanced Energy Materials, 2025, 15(19): 2404963

[3] Qin J , Wu F , Dou Y . . Advanced catalysts for the chemical recycling of plastic waste. Advanced Materials, 2025,

[4] Miao P , Zhao J , Wang P . . Enhanced photocatalytic hydrogen production from poly (vinyl alcohol) plastic-dissolved wastewater. ACS Materials Letters, 2024, 6(2): 590–597

[5] Kang H , Washington A , Capobianco M D . . Concentration-dependent photocatalytic upcycling of poly (ethylene terephthalate) plastic waste. ACS Materials Letters, 2023, 5(11): 3032–3041

[6] Geyer R , Jambeck J R , Law K L . Production, use, and fate of all plastics ever made. Science Advances, 2017, 3(7): e1700782

[7] Chu S , Zhang B , Zhao X . . Photocatalytic conversion of plastic waste: From photodegradation to photosynthesis. Advanced Energy Materials, 2022, 12(22): 2200435

[8] Iqbal B , Zhao T , Yin W . . Impacts of soil microplastics on crops: A review. Applied Soil Ecology, 2023, 181: 104680

[9] Cao R , Xiao D , Wang M . . Solar-driven photocatalysis for recycling and upcycling plastics. Applied Catalysis B: Environmental, 2024, 341: 123357

[10] Jehanno C , Alty J W , Roosen M . . Critical advances and future opportunities in upcycling commodity polymers. Nature, 2022, 603(7903): 803–814

[11] Tang X , Han X , Sulaiman N H M . . Recent advances in the photoreforming of plastic waste: Principles, challenges, and perspectives. Industrial & Engineering Chemistry Research, 2023, 62(23): 9032–9045

[12] Kang S , Yuan W , Chen W . . Recent advances on solar-driven valorization of polyethylene terephthalate plastics into value-added chemicals. Nanotechnology, 2023, 34(46): 462001

[13] Payanthoth N S , Mut N N N , Samanta P . . A review of biodegradation and formation of biodegradable microplastics in soil and freshwater environments. Applied Biological Chemistry, 2024, 67(1): 110

[14] Zhang Y F , Huang Z Y , Li Y F . . The degradability of microplastics may not necessarily equate to environmental friendliness: A case study of cucumber seedlings with disturbed photosynthesis. Agriculture, 2023, 14(1): 53

[15] Yang Z , Lü F , Zhang H . . Is incineration the terminator of plastics and microplastics. Journal of Hazardous Materials, 2021, 401: 123429

[16] Redko V , Wolska L , Potrykus M . . Environmental impacts of 5-year plastic waste deposition on municipal waste landfills: A follow-up study. Science of the Total Environment, 2024, 906: 167710

[17] Schade A , Melzer M , Zimmermann S . . Plastic waste recycling—A chemical recycling perspective. ACS Sustainable Chemistry & Engineering, 2024, 12(33): 12270–12288

[18] Zhao X , Boruah B , Chin K F . . Upcycling to sustainably reuse plastics. Advanced Materials, 2022, 34(25): 2100843

[19] Qureshi M S , Oasmaa A , Pihkola H . . Pyrolysis of plastic waste: Opportunities and challenges. Journal of Analytical and Applied Pyrolysis, 2020, 152: 104804

[20] Ellis L D , Rorrer N A , Sullivan K P . . Chemical and biological catalysis for plastics recycling and upcycling. Nature Catalysis, 2021, 4(7): 539–556

[21] Cudjoe D , Wang H . Plasma gasification versus incineration of plastic waste: Energy, economic and environmental analysis. Fuel Processing Technology, 2022, 237: 107470

[22] Tan T , Wang W , Zhang K . . Upcycling plastic wastes into value-added products by heterogeneous catalysis. ChemSusChem, 2022, 15(14): e202200522

[23] Weng Y , Hong C B , Zhang Y . . Catalytic depolymerization of polyester plastics toward closed-loop recycling and upcycling. Green Chemistry, 2024, 26(2): 571–592

[24] Wang C , Han H , Wu Y . . Nanocatalyzed upcycling of the plastic wastes for a circular economy. Coordination Chemistry Reviews, 2022, 458: 214422

[25] Chen X , Wang Y , Zhang L . Recent progress in the chemical upcycling of plastic wastes. ChemSusChem, 2021, 14(19): 4137–4151

[26] Uekert T , Bajada M A , Schubert T . . Scalable photocatalyst panels for photoreforming of plastic, biomass and mixed waste in flow. ChemSusChem, 2021, 14(19): 4190–4197

[27] Feng S , Nguyen P T T , Ma X . . Photorefinery of biomass and plastics to renewable chemicals using heterogeneous catalysts. Angewandte Chemie International Edition, 2024, 63(37): e202408504

[28] He D , Huang G , Zhou Z . . Recent progress for designing of catalysts for photothermal conversion of plastic wastes. Advanced Functional Materials, 2024,

[29] Hu Q , Zhang Z , He D . . Progress and perspective for “green” strategies of catalytic plastics conversion into fuels by regulating half-reactions. Journal of the American Chemical Society, 2024, 146(25): 16950–16962

[30] Zhang X , Jun M , Zu W . . Photoreforming of microplastics: Challenges and opportunities for sustainable environmental remediation. Small, 2024, 20(46): 2403347

[31] Wang J , Zhang C , Wang Y . Current advances in the photoconversion of plastics: the catalysts and reaction pathways. ChemSusChem, 2025, 18(7): e202401700

[32] Li Z , Yang Y , Zhang C . . Atomically engineering the metal-support interaction of single-atom Cu/TiO₂ for efficient polyethylene terephthalate plastic photoreforming. Chem Catalysis, 2024, 4(3): 100902

[33] Paiman S H , Md Noor S F , Ngadi N . . Insight into photocatalysis technology as a promising approach to tackle microplastics pollution through degradation and upcycling. Chemical Engineering Journal, 2023, 467: 143534

[34] Mountanea O G , Skolia E , Kokotos C G . Photochemical upcycling and recycling of plastics: Achievements and future opportunities. Green Chemistry, 2024, 26(15): 8528–8549

[35] Anh Nguyen T K , Trần-Phú T , Daiyan R . . From plastic waste to green hydrogen and valuable chemicals using sunlight and water. Angewandte Chemie International Edition, 2024, 63(32): e202401746

[36] Bhattacharjee S , Andrei V , Pornrungroj C . . Reforming of soluble biomass and plastic derived waste using a bias-free Cu₃₀Pd₇₀| perovskite| Pt photoelectrochemical device. Advanced Functional Materials, 2022, 32(7): 2109313

[37] Zhang B , Zhang H , Pan Y . . Photoelectrochemical conversion of plastic waste into high-value chemicals coupling hydrogen production. Chemical Engineering Journal, 2023, 462: 142247

[38] Yue S , Zhao Z , Zhang T . . Photoreforming of plastic waste to sustainable fuels and chemicals: Waste to energy. Environmental Science & Technology, 2024, 58(52): 22865–22879

[39] Miao H , Zeng G , Wu J . . In situ construction of metal phosphide-anchored Zn_0.5Cd_0.5S Schottky junction photocatalysts for efficient hydrogen evolution via photocatalytic reforming of plastics. International Journal of Hydrogen Energy, 2025, 102: 963–971

[40] Shelake S P , Sutar D N , Abraham B M . . Emerging photoreforming process to hydrogen production: A future energy. Advanced Functional Materials, 2024, 34(40): 2403795

[41] Zheng K , Wu Y , Hu Z . . Progress and perspective for conversion of plastic wastes into valuable chemicals. Chemical Society Reviews, 2023, 52(1): 8–29

[42] Kang S , Sun T , Ma Y . . Artificial photosynthesis bringing new vigor into plastic wastes. SmartMat, 2023, 4(4): e1202

[43] Han M , Zhu S , Xia C . . Photocatalytic upcycling of poly(ethylene terephthalate) plastic to high-value chemicals. Applied Catalysis B: Environmental, 2022, 316: 121662

[44] Shen M , Hu T , Huang W . . Can incineration completely eliminate plastic wastes? An investigation of microplastics and heavy metals in the bottom ash and fly ash from an incineration plant. Science of the Total Environment, 2021, 779: 146528

[45] Vollmer I , Jenks M J , Roelands M C . . Beyond mechanical recycling: giving new life to plastic waste. Angewandte Chemie International Edition, 2020, 59(36): 15402–15423

[46] Suzuki G , Uchida N , Tuyen L H . . Mechanical recycling of plastic waste as a point source of microplastic pollution. Environmental Pollution, 2022, 303: 119114

[47] Jung S H , Cho M H , Kang B S . . Pyrolysis of a fraction of waste polypropylene and polyethylene for the recovery of BTX aromatics using a fluidized bed reactor. Fuel Processing Technology, 2010, 91(3): 277–284

[48] Anuar Sharuddin S D , Abnisa F , Wan Daud W M A . . A review on pyrolysis of plastic wastes. Energy Conversion and Management, 2016, 115: 308–326

[49] Lopez G , Artetxe M , Amutio M . . Thermochemical routes for the valorization of waste polyolefinic plastics to produce fuels and chemicals. A review. Renewable & Sustainable Energy Reviews, 2017, 73: 346–368

[50] Mastral F J , Esperanza E , García P . . Pyrolysis of high-density polyethylene in a fluidised bed reactor. Influence of the temperature and residence time. Journal of Analytical and Applied Pyrolysis, 2002, 63(1): 1–15

[51] Maqsood T , Dai J , Zhang Y . . Pyrolysis of plastic species: A review of resources and products. Journal of Analytical and Applied Pyrolysis, 2021, 159: 105295

[52] Sil D , Chakrabarti S . Photocatalytic degradation of PVC–ZnO composite film under tropical sunlight and artificial UV radiation: A comparative study. Solar Energy, 2010, 84(3): 476–485

[53] Uekert T , Kuehnel M F , Wakerley D W . . Plastic waste as a feedstock for solar-driven H₂ generation. Energy & Environmental Science, 2018, 11(10): 2853–2857

[54] Jiang R , Lu G , Yan Z . . Microplastic degradation by hydroxy-rich bismuth oxychloride. Journal of Hazardous Materials, 2021, 405: 124247

[55] Gong X , Tong F , Ma F . . Photoreforming of plastic waste poly (ethylene terephthalate) via in-situ derived CN-CNTs-NiMo hybrids. Applied Catalysis B. Environment and Energy, 2022, 307: 121143

[56] Xu J , Jiao X , Zheng K . . Plastics-to-syngas photocatalysed by Co–Ga₂O₃ nanosheets. National Science Review, 2022, 9(9): nwac011

[57] Jahirul M , Rasul M , Schaller D . . Transport fuel from waste plastics pyrolysis—A review on technologies, challenges and opportunities. Energy Conversion and Management, 2022, 258: 115451

[58] Dai L , Zhou N , Lv Y . . Pyrolysis technology for plastic waste recycling: A state-of-the-art review. Progress in Energy and Combustion Science, 2022, 93: 101021

[59] Gebre S H , Sendeku M G , Bahri M . Recent trends in the pyrolysis of non-degradable waste plastics. ChemistryOpen, 2021, 10(12): 1202–1226

[60] Deng Y , Chen J , Zhang Q . . Photocatalytic upcycling of different types of plastic wastes: A mini review. ChemPlusChem, 2024, 89(11): e202400336

[61] Eisenreich F . Photocatalysis as an effective tool for upcycling polymers into value-added molecules. Angewandte Chemie International Edition, 2023, 62(29): e202301303

[62] Li C , Kong X Y , Lyu M . . Upcycling of non-biodegradable plastics by base metal photocatalysis. Chem, 2023, 9(9): 2683–2700

[63] Jiang Y , Zhang H , Hong L . . An integrated plasma–photocatalytic system for upcycling of polyolefin plastics. ChemSusChem, 2023, 16(14): e202300106

[64] Fujishima A , Honda K . Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238(5358): 37–38

[65] Ashraf M , Ullah N , Khan I . . Photoreforming of waste polymers for sustainable hydrogen fuel and chemicals feedstock: waste to energy. Chemical Reviews, 2023, 123(8): 4443–4509

[66] Agosti A , Nakibli Y , Amirav L . . Photosynthetic H₂ generation and organic transformations with CdSe@CdS-Pt nanorods for highly efficient solar-to-chemical energy conversion. Nano Energy, 2020, 70: 104510

[67] Lin L , Yi J , Wang J . . Enhancing microplastic degradation through synergistic photocatalytic and pretreatment approaches. Langmuir, 2024, 40(43): 22582–22590

[68] Guo Z , He Q , Wang H . . Chemical recycling of various PET plastic waste under alkaline hydrolysis via the LSR method. Inorganic Chemistry Communications, 2024, 159: 111744

[69] Fang P , Lu X , Zhou Q . . Controlled alcoholysis of PET to obtain oligomers for the preparation of PET-PLA copolymer. Chemical Engineering Journal, 2023, 451: 138988

[70] Barnard E , Rubio Arias J J , Thielemans W . Chemolytic depolymerisation of PET: A review. Green Chemistry, 2021, 23(11): 3765–3789

[71] Taniguchi I , Yoshida S , Hiraga K . . Biodegradation of PET: Current status and application aspects. ACS Catalysis, 2019, 9(5): 4089–4105

[72] Bhattacharjee S , Guo C , Lam E . . Chemoenzymatic photoreforming: A sustainable approach for solar fuel generation from plastic feedstocks. Journal of the American Chemical Society, 2023, 145(37): 20355–20364

[73] Kang S , Sun T , Ma Y . . Artificial photosynthesis bringing new vigor into plastic wastes. SmartMat, 2023, 4(4): e1202

[74] Chen A , Yang M Q , Wang S . . Recent advancements in photocatalytic valorization of plastic waste to chemicals and fuels. Frontiers in Nanotechnology, 2021, 3: 723120

[75] Kawai T , Sakata T . Photocatalytic hydrogen production from water by the decomposition of poly-vinylchloride, protein, algae, dead insects, and excrement. Chemistry Letters, 1981, 10(1): 81–84

[76] Lin J , Hu K , Wang Y . . Tandem microplastic degradation and hydrogen production by hierarchical carbon nitride-supported single-atom iron catalysts. Nature Communications, 2024, 15(1): 8769

[77] Feng S , Nguyen P T T , Ma X . . Photorefinery of biomass and plastics to renewable chemicals using heterogeneous catalysts. Angewandte Chemie International Edition, 2024, 63(37): e202408504

[78] Qin J , Dou Y , Zhou J . . Photocatalytic valorization of plastic waste over zinc oxide encapsulated in a metal-organic framework. Advanced Functional Materials, 2023, 33(28): 2214839

[79] Yin Z , Chen H , Wang Q . . Construction of an interface interaction in a g-C₃N₄/CdS/NiS for photoreforming of plastic and clean hydrogen regeneration. Journal of Colloid and Interface Science, 2024, 675: 218–225

[80] Su W , Zhang Y , Kuklin A . . Enhanced charge transfer dynamics in a NiCo₂S₄–Zn_xCd_1–xS photothermal catalyst for efficient photoreforming of waste plastic. ACS Catalysis, 2024, 14(18): 13927–13939

[81] Li T , Vijeta A , Casadevall C . . Bridging plastic recycling and organic catalysis: Photocatalytic deconstruction of polystyrene via a C–H oxidation pathway. ACS Catalysis, 2022, 12(14): 8155–8163

[82] Jiao X , Zheng K , Chen Q . . Photocatalytic conversion of waste plastics into C₂ fuels under simulated natural environment conditions. Angewandte Chemie International Edition, 2020, 59(36): 15497–15501

[83] Du M , Zhang Y , Kang S . . Trash to treasure: Photoreforming of plastic waste into commodity chemicals and hydrogen over MoS₂-tipped CdS nanorods. ACS Catalysis, 2022, 12(20): 12823–12832

[84] Li Y , Wan S , Lin C . . Engineering of 2D/2D MoS₂/Cd_xZn_1−xS photocatalyst for solar H₂ evolution coupled with degradation of plastic in alkaline solution. Solar RRL, 2021, 5(6): 2000427

[85] Wakerley D W , Kuehnel M F , Orchard K L . . Solar-driven reforming of lignocellulose to H₂ with a CdS/CdO_x photocatalyst. Nature Energy, 2017, 2(4): 17021

[86] Zhang S , Li H , Wang L . . Boosted photoreforming of plastic waste via defect-rich NiPS₃ nanosheets. Journal of the American Chemical Society, 2023, 145(11): 6410–6419

[87] Miao Y , Zhao Y , Gao J . . Direct photoreforming of real-world polylactic acid plastics into highly selective value-added pyruvic acid under visible light. Journal of the American Chemical Society, 2024, 146(7): 4842–4850

[88] Uekert T , Kasap H , Reisner E . Photoreforming of nonrecyclable plastic waste over a carbon nitride/nickel phosphide catalyst. Journal of the American Chemical Society, 2019, 141(38): 15201–15210

[89] Guo S , Huang Y , Li D . . Visible-light-driven photoreforming of poly(ethylene terephthalate) plastics via carbon nitride porous microtubes. Chemical Communications, 2023, 59(50): 7791–7794

[90] Han M , Zhu S , Xia C . . Photocatalytic upcycling of poly (ethylene terephthalate) plastic to high-value chemicals. Applied Catalysis B: Environmental, 2022, 316: 121662

[91] Cao R , Zhang M Q , Hu C . . Catalytic oxidation of polystyrene to aromatic oxygenates over a graphitic carbon nitride catalyst. Nature Communications, 2022, 13(1): 4809

[92] Liu X , Yang Y , Wan S . . Tuning the surface hydrophilicity of a C₃N₄ nanosheet for efficient photocatalytic H₂ evolution coupled with microplastic degradation. International Journal of Hydrogen Energy, 2023, 48(71): 27599–27610

[93] Merchant A , Batzner S , Schoenholz S S . . Scaling deep learning for materials discovery. Nature, 2023, 624(7990): 80–85

[94] Lifar M S , Tereshchenko A A , Bulgakov A N . . Optimal dynamic regimes for CO oxidation discovered by reinforcement learning. ACS Omega, 2024, 9(26): 27987–27997

[95] Uekert T , Pichler C M , Schubert T . . Solar-driven reforming of solid waste for a sustainable future. Nature Sustainability, 2020, 4(5): 383–391

RIGHTS & PERMISSIONS

Higher Education Press 2025