Progress on Si-based photoelectrodes for industrial production of green hydrogen by solar-driven water splitting

Abstract

Solar power has been regarded as the ultimate green-energy source because of its inexhaustibility and eco-friendliness. The solar-driven water-splitting technology for green hydrogen production is considered to be one of effective ways for solar energy harvesting and storage, which may provide solutions for the energy crisis and environmental issues. In the past decades, great progress has been achieved in this area. Photoelectrochemical (PEC) water splitting is especially promising for the production of solar fuels because of expected large-scale industrial application. Silicon (Si), as an ideal candidate for the photoelectrode, is the most suitable material for the PEC device in industrial photocatalytic water splitting because of its abundance, mature fabrication technology, and suitable band gap. Here, we give a systematic review on the recent progress for Si-based photoelectrodes for water splitting with a focus on the industrial application. Particularly, the strategies, such as band-alignment control, morphology design, and surface engineering, are summarized to enhance the PEC performance and durability for practical application. Furthermore, the perspective for the design of commercial Si-based PEC devices with high PEC performance, long-term stability, large-size, and low cost are given at the end, which shall guide the development of PEC water splitting for industrial application.

Keywords

industrial application / large-scale development / photoelectrochemical water splitting / silicon-based photoelectrode

References

[1] McGlade C, Ekins P. The geographical distribution of fossil fuels unused when limiting global warming to 2℃. Nature. 2015; 517(7533): 187-190.

[2] Abas N, Kalair A, Khan N. Review of fossil fuels and future energy technologies. Futures. 2015; 69: 31-49.

[3] Bilgen S. Structure and environmental impact of global energy consumption. Renew Sustain Energy Rev. 2014; 38: 890-902.

[4] Holechek JL, Geli HM, Sawalhah MN, Valdez R. A global assessment: can renewable energy replace fossil fuels by 2050? Sustainability. 2022; 14(8):4792.

[5] Zou C, Zhao Q, Zhang G, Xiong B. Energy revolution: from a fossil energy era to a new energy era. Nat Gas Ind B. 2016; 3(1): 1-11.

[6] Kim JH, Hansora D, Sharma P, Jang J-W, Lee JS. Toward practical solar hydrogen production - an artificial photosynthetic leaf-to-farm challenge. Chem Soc Rev. 2019; 48(7): 1908-1971.

[7] Granqvist CG. Solar energy materials. Adv Mater. 2003; 15(21): 1789-1803.

[8] Lewis NS. Toward cost-effective solar energy use. Science. 2007; 315(5813): 798-801.

[9] Kannan N, Vakeesan D. Solar energy for future world: - a review. Renew Sustain Energy Rev. 2016; 62: 1092-1105.

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

[11] Squadrito G, Maggio G, Nicita A. The green hydrogen revolution. Renew Energy. 2023; 216:119041.

[12] Brandon N, Armstrong F, Chan S, et al. The role of hydrogen and ammonia in meeting the net zero challenge.Clim Change: Science and Solutions, Briefing. 2021; 4: 1-13.

[13] Armaroli N, Balzani V. The hydrogen issue. ChemSusChem. 2011; 4(1): 21-36.

[14] Ball M, Wietschel M. The future of hydrogen - opportunities and challenges☆. Int J Hydrogen Energy. 2009; 34(2): 615-627.

[15] Guan D, Wang B, Zhang J, et al. Hydrogen society: from present to future. Energy Environ Sci. 2023; 16(11): 4926-4943.

[16] Panchenko VA, Daus YV, Kovalev AA, Yudaev IV, Litti YV. Prospects for the production of green hydrogen: review of countries with high potential. Int J Hydrogen Energy. 2023; 48(12): 4551-4571.

[17] Turner JA. Sustainable hydrogen production. Science. 2004; 305(5686): 972-974.

[18] Zhao H, Yuan Z-Y. Progress and perspectives for solar-driven water electrolysis to produce green hydrogen. Adv Energy Mater. 2023; 13(16):2300254.

[19] Tong R, Ng KW, Wang X, Wang S, Wang X, Pan H. Two-dimensional materials as novel co-catalysts for efficient solar-driven hydrogen production. J Mater Chem A. 2020; 8(44): 23202-23230.

[20] Shao M, Shao Y, Ding S, et al. Vanadium disulfide decorated graphitic carbon nitride for super-efficient solar-driven hydrogen evolution. Appl Catal B Environ. 2018; 237: 295-301.

[21] Chen W, Hou X, Shi X, Pan H. Two-dimensional janus transition metal oxides and chalcogenides: multifunctional properties for photocatalysts, electronics, and energy conversion. ACS Appl Mater Interfaces. 2018; 10(41): 35289-35295.

[22] Takata T, Jiang J, Sakata Y, et al. Photocatalytic water splitting with a quantum efficiency of almost unity. Nature. 2020; 581(7809): 411-414.

[23] Zuo G, Wang Y, Teo WL, Xian Q, Zhao Y. Direct Z-scheme TiO₂-ZnIn₂S₄ nanoflowers for cocatalyst-free photocatalytic water splitting. Appl Catal B Environ. 2021; 291:120126.

[24] Zhou P, Navid IA, Ma Y, et al. Solar-to-hydrogen efficiency of more than 9% in photocatalytic water splitting. Nature. 2023; 613(7942): 66-70.

[25] Rahman M, Tian H, Edvinsson T. Revisiting the limiting factors for overall water-splitting on organic photocatalysts. Angew Chem. 2020; 132(38): 16418-16433.

[26] Faraji M, Yousefi M, Yousefzadeh S, et al. Two-dimensional materials in semiconductor photoelectrocatalytic systems for water splitting. Energy Environ Sci. 2019; 12(1): 59-95.

[27] Fu C-F, Wu X, Yang J. Material design for photocatalytic water splitting from a theoretical perspective. Adv Mater. 2018; 30(48):1802106.

[28] Liu J, Luo Z, Mao X, et al. Recent advances in self-supported semiconductor heterojunction nanoarrays as efficient photoanodes for photoelectrochemical water splitting. Small. 2022; 18(48):2204553.

[29] Baek M, Kim G-W, Park T, Yong K. NiMoFe and NiMoFeP as complementary electrocatalysts for efficient overall water splitting and their application in PV-electrolysis with STH 12.3%. Small. 2019; 15(49):1905501.

[30] Chen H, Song L, Ouyang S, Wang J, Lv J, Ye J. Co and Fe codoped WO_2.72 as alkaline-solution-available oxygen evolution reaction catalyst to construct photovoltaic water splitting system with solar-to-hydrogen efficiency of 16.9%. Adv Sci. 2019; 6(16):1900465.

[31] Park H, Park IJ, Lee MG, et al. Water splitting exceeding 17% solar-to-hydrogen conversion efficiency using solution-processed Ni-based electrocatalysts and perovskite/Si tandem solar cell. ACS Appl Mater Interfaces. 2019; 11(37): 33835-33843.

[32] Sayama K, Miseki Y. Research and development of solar hydrogen production—Toward the realization of ingenious photocatalysis-electrolysis hybrid system. Synthesiology English edition. 2014; 7(2): 79-91.

[33] Li Z, Luo W, Zhang M, Feng J, Zou Z. Photoelectrochemical cells for solar hydrogen production: current state of promising photoelectrodes, methods to improve their properties, and outlook. Energy Environ Sci. 2013; 6(2): 347-370.

[34] Li Z, Fang S, Sun H, Chung R-J, Fang X, He J-H. Solar hydrogen. Adv Energy Mater. 2023; 13(8):2203019.

[35] Yao T, An X, Han H, Chen JQ, Li C. Photoelectrocatalytic materials for solar water splitting. Adv Energy Mater. 2018; 8(21):1800210.

[36] Jun SE, Kim Y-H, Kim J, et al. Atomically dispersed iridium catalysts on silicon photoanode for efficient photoelectrochemical water splitting. Nat Commun. 2023; 14(1): 609.

[37] Sun K, Kuang Y, Verlage E, Brunschwig BS, Tu CW, Lewis NS. Sputtered NiO_x films for stabilization of p⁺n-InP photoanodes for solar-driven water oxidation. Adv Energy Mater. 2015; 5(11):1402276.

[38] Gupta B, Zhang D, Chen H, Jagadish C, Tan HH, Karuturi S. Ferri-hydrite: a novel electron-selective contact layer for InP photovoltaic and photoelectrochemical cells. ACS Appl Mater Interfaces. 2023; 15(38): 44912-44920.

[39] Tariq F, Abdullah A, Kulkarni MA, et al. Enhanced photoelectrochemical water splitting performance of GaN nanowires on textured Si (100) platforms: the role of texturing in 3.69% STH conversion efficiency. Materials Today Physics. 2023; 38:101275.

[40] Piriyev M, Loget G, Léger Y, et al. Dual bandgap operation of a GaAs/Si photoelectrode. Sol Energy Mater Sol Cell. 2023; 251:112138.

[41] Hwang S, Gu H, Young JL, et al. TiO₂/TiN interface enables integration of Ni₅P₄ electrocatalyst with a III-V tandem photoabsorber for stable unassisted solar-driven water splitting. ACS Energy Lett. 2024; 9(3): 789-797.

[42] Lin J, Han X, Liu S, et al. Nitrogen-doped cobalt-iron oxide cocatalyst boosting photoelectrochemical water splitting of BiVO₄ photoanodes. Appl Catal B Environ. 2023; 320:121947.

[43] Wang J, Ni G, Liao W, et al. Subsurface engineering induced Fermi level de-pinning in metal oxide semiconductors for photoelectrochemical water splitting. Angew Chem. 2023; 135(9):e202217026.

[44] Wang L, Zhu J, Liu X. Oxygen-vacancy-dominated cocatalyst/hematite interface for boosting solar water splitting. ACS Appl Mater Interfaces. 2019; 11(25): 22272-22277.

[45] Zhang D, Du M, Wang P, et al. Hole-storage enhanced a-Si photocathodes for efficient hydrogen production. Angew Chem Int Ed. 2021; 60(21): 11966-11972.

[46] Xia Z, Zhou X, Li J, Qu Y. Protection strategy for improved catalytic stability of silicon photoanodes for water oxidation. Sci Bull. 2015; 60(16): 1395-1402.

[47] NREL. Best Research Cell Efficiencies. https://www.nrel.gov/pv/cell-efficiency.html

[48] Gundel P, Schubert MC, Warta W. Origin of trapping in multicrystalline silicon. J Appl Phys. 2008; 104(7).

[49] Falster R, Voronkov VV. The engineering of intrinsic point defects in silicon wafers and crystals. Mater Sci Eng, B. 2000; 73(1): 87-94.

[50] Fan R, Mi Z, Shen M. Silicon based photoelectrodes for photoelectrochemical water splitting. Opt Express. 2019; 27(4): A51-A80.

[51] Oh S, Jung S, Lee YH, et al. Hole-Selective CoO_x/SiO_x/Si heterojunctions for photoelectrochemical water splitting. ACS Catal. 2018; 8(10): 9755-9764.

[52] Ji L, McDaniel MD, Wang S, et al. A silicon-based photocathode for water reduction with an epitaxial SrTiO₃ protection layer and a nanostructured catalyst. Nat Nanotechnol. 2015; 10(1): 84-90.

[53] Wang H-P, Sun K, Noh SY, et al. High-performance a-Si/c-Si heterojunction photoelectrodes for photoelectrochemical oxygen and hydrogen evolution. Nano Lett. 2015; 15(5): 2817-2824.

[54] Cai Q, Hong W, Jian C, Li J, Liu W. Insulator layer engineering toward stable Si photoanode for efficient water oxidation. ACS Catal. 2018; 8(10): 9238-9244.

[55] Chuang C-H, Kang P-H, Lai Y-Y, Hou C-H, Cheng Y-J. Junction engineering in Si photoanodes for efficient photoelectrochemical water splitting. ACS Appl Energy Mater. 2022; 5(7): 8483-8491.

[56] Lopes T, Dias P, Andrade L, Mendes A. An innovative photoelectrochemical lab device for solar water splitting. Sol Energy Mater Sol Cell. 2014; 128: 399-410.

[57] Vilanova A, Lopes T, Spenke C, Wullenkord M, Mendes A. Optimized photoelectrochemical tandem cell for solar water splitting. Energy Storage Mater. 2018; 13: 175-188.

[58] Balog Á, Kecsenovity E, Samu GF, He J, Fekete D, Janáky C. Paired photoelectrochemical conversion of CO₂/H₂O and glycerol at high rate. Nat Catal. 2024; 7(5): 522-535.

[59] You B, Sun Y. Innovative strategies for electrocatalytic water splitting. Acc Chem Res. 2018; 51(7): 1571-1580.

[60] Niu F, Wang D, Li F, Liu Y, Shen S, Meyer TJ. Hybrid photoelectrochemical water splitting systems: from interface design to system assembly. Adv Energy Mater. 2020; 10(11):1900399.

[61] Hien TT, Quang ND, Kim C, Kim D. Energy diagram analysis of photoelectrochemical water splitting process. Nano Energy. 2019; 57: 660-669.

[62] Cui W, Wu S, Chen F, et al. Silicon/organic heterojunction for photoelectrochemical energy conversion photoanode with a record photovoltage. ACS Nano. 2016; 10(10): 9411-9419.

[63] Fehr AMK, Agrawal A, Mandani F, et al. Integrated halide perovskite photoelectrochemical cells with solar-driven water-splitting efficiency of 20.8%. Nat Commun. 2023; 14(1):3797.

[64] Zhou X, Liu R, Sun K, Papadantonakis KM, Brunschwig BS, Lewis NS. 570 mV photovoltage, stabilized n-Si/CoO_xheterojunction photoanodes fabricated using atomic layer deposition. Energy Environ Sci. 2016; 9(3): 892-897.

[65] Sun K, McDowell MT, Nielander AC, et al. Stable solar-driven water oxidation to O₂(g) by Ni-Oxide-Coated silicon photoanodes. J Phys Chem Lett. 2015; 6(4): 592-598.

[66] Zhou X, Liu R, Sun K, et al. Interface engineering of the photoelectrochemical performance of Ni-oxide-coated n-Si photoanodes by atomic-layer deposition of ultrathin films of cobalt oxide. Energy Environ Sci. 2015; 8(9): 2644-2649.

[67] Bae D, Pedersen T, Seger B, et al. Carrier-selective p- and n-contacts for efficient and stable photocatalytic water reduction. Catal Today. 2017; 290: 59-64.

[68] Chen Z, Jaramillo TF, Deutsch TG, et al. Accelerating materials development for photoelectrochemical hydrogen production: standards for methods, definitions, and reporting protocols. J Mater Res. 2010; 25(1): 3-16.

[69] Mayer MT. Photovoltage at semiconductor-electrolyte junctions. Curr Opin Electrochem. 2017; 2(1): 104-110.

[70] Dotan H, Mathews N, Hisatomi T, Grätzel M, Rothschild A. On the solar to hydrogen conversion efficiency of photoelectrodes for water splitting. J Phys Chem Lett. 2014; 5(19): 3330-3334.

[71] Chen Z, Deutsch TG, Dinh HN, et al. Efficiency definitions in the field of PEC. In: Z Chen, HN Dinh, E Miller, eds. Photoelectrochemical Water Splitting: Standards, Experimental Methods, and Protocols. Springer; 2013: 7-16.

[72] Qi B, Wang J. Fill factor in organic solar cells. Phys Chem Chem Phys. 2013; 15(23): 8972-8982.

[73] Karuturi SK, Shen H, Sharma A, et al. Over 17% efficiency stand-alone solar water splitting enabled by perovskite-silicon tandem absorbers. Adv Energy Mater. 2020; 10(28):2000772.

[74] Jiang C, Moniz SJA, Wang A, Zhang T, Tang J. Photoelectrochemical devices for solar water splitting - materials and challenges. Chem Soc Rev. 2017; 46(15): 4645-4660.

[75] Raveendran A, Chandran M, Dhanusuraman R. A comprehensive review on the electrochemical parameters and recent material development of electrochemical water splitting electrocatalysts. RSC Adv. 2023; 13(6): 3843-3876.

[76] Anantharaj S, Ede SR, Sakthikumar K, Karthick K, Mishra S, Kundu S. Recent trends and perspectives in electrochemical water splitting with an emphasis on sulfide, selenide, and phosphide catalysts of Fe, Co, and Ni: a review. ACS Catal. 2016; 6(12): 8069-8097.

[77] Zhang D, Shi J, Zi W, Wang P, Liu S. Recent advances in photoelectrochemical applications of silicon materials for solar-to-chemicals conversion. ChemSusChem. 2017; 10(22): 4324-4341.

[78] Yang J, Cooper JK, Toma FM, et al. A multifunctional biphasic water splitting catalyst tailored for integration with high-performance semiconductor photoanodes. Nat Mater. 2017; 16(3): 335-341.

[79] Arunachalam M, Subhash Kanase R, Ganapati Badiger J, et al. Durable bias-free solar Water-Splitting cell composed of n⁺p- Si/Nb₂O₅/NiPt photocathode and W:BiVO₄/NiCo(O-OH)₂ photoanode. Chem Eng J. 2023; 474:145262.

[80] Jia Q, Yu C, Liu W, et al. High performance n+p-Si/Ti/NiS O photocathode for photoelectrochemical hydrogen evolution in alkaline solution. J Energy Chem. 2019; 30: 101-107.

[81] Fan R, Min J, Li Y, et al. n-type silicon photocathodes with Al-doped rear p⁺ emitter and Al₂O₃-coated front surface for efficient and stable H₂ production. Appl Phys Lett. 2015; 106(21):213901.

[82] Walter MG, Warren EL, McKone JR, et al. Solar water splitting cells. Chem Rev. 2010; 110(11): 6446-6473.

[83] Zhang Z, Yates JT, Band bending in semiconductors: chemical and physical consequences at surfaces and interfaces. Chem Rev. 2012; 112(10): 5520-5551.

[84] Chen L, Yang J, Klaus S, et al. p-Type transparent conducting oxide/n-Type semiconductor heterojunctions for efficient and stable solar water oxidation.J Am Chem Soc. 2015; 137(30): 9595-9603.

[85] Wang J, Zhou T, Zhang Y, et al. Type-II heterojunction CdIn₂S₄/BiVO₄ coupling with CQDs to improve PEC water splitting performance synergistically. ACS Appl Mater Interfaces. 2022; 14(40): 45392-45402.

[86] Mayer MT, Du C, Wang D. Hematite/Si nanowire dual-absorber system for photoelectrochemical water splitting at low applied potentials.J Am Chem Soc. 2012; 134(30): 12406-12409.

[87] Tang R, Zhou S, Yuan Z, Yin L. Metal-Organic Framework Derived Co₃O₄/TiO₂/Si Heterostructured Nanorod Array Photoanodes for Efficient Photoelectrochemical Water Oxidation.Adv Funct Mater. 2017; 27(37):1701102.

[88] Jung G, Moon C, Martinho F, et al. Monolithically integrated BiVO₄/Si tandem devices enabling unbiased photoelectrochemical water splitting.Adv Energy Mater. 2023; 13(35):2301235.

[89] Tung RT. Chemical bonding and Fermi level pinning at metal-semiconductor interfaces. Phys Rev Lett. 2000; 84(26): 6078-6081.

[90] Scheuermann AG, McIntyre PC. Atomic layer deposited corrosion protection: a path to stable and efficient photoelectrochemical cells.J Phys Chem Lett. 2016; 7(14): 2867-2878.

[91] Dong Y, Abbasi M, Meng J, et al. Substantial lifetime enhancement for Si-based photoanodes enabled by amorphous TiO₂ coating with improved stoichiometry.Nat Commun. 2023; 14(1):1865.

[92] Liu B, Feng S, Yang L, et al. Bifacial passivation of n-silicon metal-insulator-semiconductor photoelectrodes for efficient oxygen and hydrogen evolution reactions.Energy Environ Sci. 2020; 13(1): 221-228.

[93] Shi Q, Zhu C, Du D, Lin Y. Robust noble metal-based electrocatalysts for oxygen evolution reaction. Chem Soc Rev. 2019; 48(12): 3181-3192.

[94] Lei Z, Cai W, Rao Y, et al. Coordination modulation of iridium single-atom catalyst maximizing water oxidation activity. Nat Commun. 2022; 13(1): 24.

[95] Gao R, Yan D. Recent development of Ni/Fe-based micro/nanostructures toward photo/electrochemical water oxidation. Adv Energy Mater. 2020; 10(11):1900954.

[96] Khosravi M, Mohammadi MR. Trends and progress in application of cobalt-based materials in catalytic, electrocatalytic, photocatalytic, and photoelectrocatalytic water splitting. Photosynth Res. 2022; 154(3): 329-352.

[97] Lv X, Li X, Yang C, et al. Large-size, porous, ultrathin NiCoP nanosheets for efficient electro/photocatalytic water splitting. Adv Funct Mater. 2020; 30(16):1910830.

[98] Cai W, Xiong H, Su X, Zhou H, Shen M, Fang L. Enhanced photoelectrochemical properties of copper-assisted catalyzed etching black silicon by electrodepositing cobalt. Appl Phys Lett. 2017; 111(20):203902.

[99] Pijpers JJH, Winkler MT, Surendranath Y, Buonassisi T, Nocera DG. Light-induced water oxidation at silicon electrodes functionalized with a cobalt oxygen-evolving catalyst. Proc Natl Acad Sci USA. 2011; 108(25): 10056-10061.

[100] Fan R, Cheng S, Huang G, et al. Unassisted solar water splitting with 9.8% efficiency and over 100 h stability based on Si solar cells and photoelectrodes catalyzed by bifunctional Ni-Mo/Ni. J Mater Chem A. 2019; 7(5): 2200-2209.

[101] Xu G, Xu Z, Shi Z, et al. Silicon photoanodes partially covered by Ni@Ni(OH)₂ core-shell particles for photoelectrochemical water oxidation. ChemSusChem. 2017; 10(14): 2897-2903.

[102] Oh K, Dorcet V, Fabre B, Loget G. Dissociating water at n-Si photoanodes partially covered with Fe catalysts. Adv Energy Mater. 2020; 10(3):1902963.

[103] Peng S, Liu D, Ying Z, et al. Industrial-Si-based photoanode for highly efficient and stable water splitting. J Colloid Interface Sci. 2024; 671: 434-440.

[104] Chen Z, Fang K, Bu Y, Ao J-P. Development of functionalized CoO_x-NiFe LDH bi-layers to improve the photoelectrochemical water oxidation property of n-Si photoanode. J Alloys Compd. 2023; 942:168948.

[105] Choi S, Lee SA, Yang JW, et al. Boosted charge transport through Au-modified NiFe layered double hydroxide on silicon for efficient photoelectrochemical water oxidation. J Mater Chem A. 2023; 11(33): 17503-17513.

[106] McKone JR, Warren EL, Bierman MJ, et al. Evaluation of Pt, Ni, and Ni-Mo electrocatalysts for hydrogen evolution on crystalline Si electrodes. Energy Environ Sci. 2011; 4(9): 3573-3583.

[107] Boettcher SW, Warren EL, Putnam MC, et al. Photoelectrochemical hydrogen evolution using Si microwire arrays. J Am Chem Soc. 2011; 133(5): 1216-1219.

[108] Wang Y, Zhang G, Xu W, et al. A 3D nanoporous Ni-Mo electrocatalyst with negligible overpotential for alkaline hydrogen evolution. Chemelectrochem. 2014; 1(7): 1138-1144.

[109] Lim SY, Kim Y-R, Ha K, et al. Light-guided electrodeposition of non-noble catalyst patterns for photoelectrochemical hydrogen evolution. Energy Environ Sci. 2015; 8(12): 3654-3662.

[110] Morales-Guio CG, Liardet L, Mayer MT, Tilley SD, Grätzel M, Hu X. Photoelectrochemical hydrogen production in alkaline solutions using Cu₂O coated with earth-abundant hydrogen evolution catalysts. Angew Chem Int Ed. 2015; 54(2): 664-667.

[111] Li S, Yang G, Ge P, et al. Engineering heterogeneous NiS₂/NiS cocatalysts with progressive electron transfer from planar p-Si photocathodes for solar hydrogen evolution. Small Methods. 2021; 5(4):2001018.

[112] Zhang H, Hagen DJ, Li X, et al. Atomic layer deposition of cobalt phosphide for efficient water splitting. Angew Chem Int Ed. 2020; 59(39): 17172-17176.

[113] Liu F, Shi C, Guo X, et al. Rational design of better hydrogen evolution electrocatalysts for water splitting: a review. Adv Sci. 2022; 9(18):2200307.

[114] Digdaya IA, Adhyaksa GWP, Trześniewski BJ, Garnett EC, Smith WA. Interfacial engineering of metal-insulator-semiconductor junctions for efficient and stable photoelectrochemical water oxidation. Nat Commun. 2017; 8(1):15968.

[115] Das C, Kot M, Henkel K, Schmeisser D. Engineering of sub-nanometer SiO_x thickness in Si photocathodes for optimized open circuit potential.ChemSusChem. 2016; 9(17): 2332-2336.

[116] Li S, She G, Chen C, et al. Enhancing the photovoltage of Ni/n-Si photoanode for water oxidation through a rapid thermal process.ACS Appl Mater Interfaces. 2018; 10(10): 8594-8598.

[117] Lee S, Ji L, De Palma AC, Yu ET. Scalable, highly stable Si-based metal-insulator-semiconductor photoanodes for water oxidation fabricated using thin-film reactions and electrodeposition.Nat Commun. 2021; 12(1):3982.

[118] Ma J, Chi H, Wang A, et al. Identifying and removing the interfacial states in metal-oxide-semiconductor Schottky Si photoanodes for the highest fill factor.J Am Chem Soc. 2022; 144(38): 17540-17548.

[119] Scheuermann AG, Lawrence JP, Kemp KW, et al. Design principles for maximizing photovoltage in metal-oxide-protected water-splitting photoanodes.Nat Mater. 2016; 15(1): 99-105.

[120] Zhang F, Yu X, Hu J, Lei L, He Y, Zhang X. Coupling Ru-MoS₂ heterostructure with silicon for efficient photoelectrocatalytic water splitting. Chem Eng J. 2021; 423:130231.

[121] Cao Y. ACS Nano. Roadmap and direction toward high-performance MoS₂ hydrogen evolution catalysts. 2021; 15(7): 11014-11039.

[122] Thalluri SM, Wei B, Welter K, et al. Inverted pyramid textured p-silicon covered with Co₂P as an efficient and stable solar hydrogen evolution photocathode. ACS Energy Lett. 2019; 4(7): 1755-1762.

[123] Shaner MR, Fountaine KT, Ardo S, Coridan RH, Atwater HA, Lewis NS. Photoelectrochemistry of core-shell tandem junction n-p⁺-Si/n-WO₃microwire array photoelectrodes. Energy Environ Sci. 2014; 7(2): 779-790.

[124] Roy K, Maitra S, Ghosh D, Kumar P, Devi P. 2D-Heterostructure assisted activation of MoS₂ basal plane for enhanced photoelectrochemical hydrogen evolution reaction. Chem Eng J. 2022; 435:134963.

[125] Zhao Y, Song W, Wang D, Chen H, Zhou G. Enhanced light trapping and charge separation via pyramidal Cu₂O/NiCo-LDH photocathode for efficient water splitting. ACS Appl Energy Mater. 2022; 5(1): 992-1001.

[126] Bagal IV, Arunachalam M, Abdullah A, et al. Toward stable photoelectrochemical water splitting using NiOOH coated hierarchical nitrogen-doped ZnO-Si nanowires photoanodes. J Energy Chem. 2022; 71: 45-55.

[127] Li H, Hu Y, Wang H, Tao Q, Zhu Y, Yang Y. Full-spectrum absorption enhancement in a-Si:H thin-film solar cell with a composite light-trapping structure. Sol RRL. 2021; 5(3):2000524.

[128] Nandjou F, Haussener S. Degradation in photoelectrochemical devices: review with an illustrative case study. J Phys Appl Phys. 2017; 50(12):124002.

[129] Bae D, Seger B, Vesborg PCK, Hansen O, Chorkendorff I. Strategies for stable water splitting via protected photoelectrodes. Chem Soc Rev. 2017; 46(7): 1933-1954.

[130] Li S, She G, Xu J, et al. Metal silicidation in conjunction with dopant segregation: a promising strategy for fabricating high-performance silicon-based photoanodes. ACS Appl Mater Interfaces. 2020; 12(35): 39092-39097.

[131] Li S, Zhang H, She G, et al. NiSi₂/p-Si Schottky junction photocathode with a high-quality epitaxial interface for efficient hydrogen evolution. ACS Appl Energy Mater. 2021; 4(10): 11574-11579.

[132] Zhang H, She G, Xu J, et al. Electrochemical surface reconstructed Pt_xSi/PtSi/p-Si photocathodes for achieving high efficiency in photoelectrochemical H₂ generation. J Mater Chem A. 2022; 10(9): 4952-4959.

[133] He L, Zhou W, Cai D, Mao SS, Sun K, Shen S. Pulsed laser-deposited n-Si/NiO_xphotoanodes for stable and efficient photoelectrochemical water splitting. Catal Sci Technol. 2017; 7(12): 2632-2638.

[134] Yin Z, Shi Y, Shen S. A n-Si/CoOx/Ni:CoOOH photoanode producing 600 mV photovoltage for efficient photoelectrochemical water splitting. Sci China Mater. 2022; 65(12): 3442-3451.

[135] Yin Z, Zhang K, Shi Y, Wang Y, Shen S. An interface-cascading silicon photoanode with strengthened built-in electric field and enriched surface oxygen vacancies for efficient photoelectrochemical water splitting. Chem Eur J. 2024; 30(15):e202303895.

[136] Wu B, Wang T, Liu B, et al. Stable solar water splitting with wettable organic-layer-protected silicon photocathodes. Nat Commun. 2022; 13(1):4460.

[137] Kim D-H, Ahn J-H, Choi WM, et al. Stretchable and foldable silicon integrated circuits. Science. 2008; 320(5875): 507-511.

[138] Iwai H, Ohmi Si. Silicon integrated circuit technology from past to future. Microelectron Reliab. 2002; 42(4): 465-491.

[139] Armin, GA; Matthew, BB; Bram, H; Thomas, M, Industrial silicon wafer solar cells - status and trends. Green. 2012; 2(4): 135-148.

[140] Fan R, Dong W, Fang L, et al. Stable and efficient multi-crystalline n⁺p silicon photocathode for H₂ production with pyramid-like surface nanostructure and thin Al₂O₃ protective layer. Appl Phys Lett. 2015; 106(1):013902.

[141] Ying Z, Yang Z, Zheng J, et al. Monolithic perovskite/black-silicon tandems based on tunnel oxide passivated contacts. Joule. 2022; 6(11): 2644-2661.

[142] Grübel B, Cimiotti G, Schmiga C, et al. Progress of plated metallization for industrial bifacial TOPCon silicon solar cells. Prog Photovoltaics Res Appl. 2022; 30(6): 615-621.

[143] Zheng J, Wei H, Ying Z, et al. Balancing charge-carrier transport and recombination for perovskite/TOPCon tandem solar cells with double-textured structures. Adv Energy Mater. 2023; 13(5):2203006.

[144] Peng S, Liu D, An K, et al. n-Si/SiO_x/CoO_x-Mo photoanode for efficient photoelectrochemical water oxidation (small 3/2024). Small. 2024; 20(3):2304376.

[145] Li S, Zhang P, Xie X, et al. Enhanced photoelectrochemical performance of planar p-Silicon by APCVD deposition of surface mesoporous hematite coating. Appl Catal B Environ. 2017; 200: 372-377.

[146] Li Y, Ding C, Li Y, et al. Engineering the SiO_x interfacial layer of Si-based metal-insulator-semiconductor junction for photoelectrochemical hydrogen production. J Catal. 2024; 434:115533.

[147] Zhang Q, Li T, Luo J, et al. Ti/Co-S catalyst covered amorphous Si-based photocathodes with high photovoltage for the HER in non-acid environments. J Mater Chem A. 2018; 6(3): 811-816.

[148] Luo Z, Liu B, Li H, et al. Multifunctional nickel film protected n-type silicon photoanode with high photovoltage for efficient and stable oxygen evolution reaction. Small Methods. 2019; 3(10):1900212.

[149] Zhou W, Dong C-L, Wang Y, et al. Manipulating metal-oxygen local atomic structures in single-junctional p-Si/WO₃ photocathodes for efficient solar hydrogen generation.Nano Res. 2021; 14(7): 2285-2293.

[150] Lee S, Wu S-H, Yu ET. Wafer-scale Si-based metal-insulator-semiconductor photoanodes for water oxidation fabricated using thin film reactions and multiple-layer electrodeposited catalysts. ACS Appl Energy Mater. 2024; 7(8): 3253-3262.

[151] Navid IA, Vanka S, Awni RA, et al. On the design and performance of InGaN/Si double-junction photocathodes. Appl Phys Lett. 2021; 118(24):243906.

[152] Dong WJ, Navid IA, Xiao Y, Lim JW, Lee J-L, Mi Z. CuS-decorated GaN nanowires on silicon photocathodes for converting CO₂ mixture gas to HCOOH. J Am Chem Soc. 2021; 143(27): 10099-10107.

[153] Deng S, Cai Y, Roemer U, et al. Mitigating parasitic absorption in Poly-Si contacts for TOPCon solar cells: a comprehensive review. Sol Energy Mater Sol Cell. 2024; 267:112704.

[154] Liu B, Wang S, Zhang G, et al. Tandem cells for unbiased photoelectrochemical water splitting. Chem Soc Rev. 2023; 52(14): 4644-4671.

[155] Pham DP, Lee S, Le AHT, Cho E-C, Hyun Cho Y, Yi J. Monocrystalline silicon-based tandem configuration for solar-to-hydrogen conversion. Inorg Chem Commun. 2020; 116:107926.

[156] Ding J, Lyu Y, Zhou H, et al. Efficiently unbiased solar-to-ammonia conversion by photoelectrochemical Cu/C/Si-TiO₂ tandems. Appl Catal B Environ. 2024; 345:123735.

[157] Chen L, Alqahtani M, Levallois C, et al. Assessment of GaPSb/Si tandem material association properties for photoelectrochemical cells. Sol Energy Mater Sol Cell. 2021; 221:110888.

[158] Jia Y, Cheng Y, Zhang Y, Ma J. A p-n-p configuration based on the cuprous oxide/silicon tandem photocathode for accelerating solar-driven hydrogen evolution. ACS Appl Mater Interfaces. 2024; 16(19): 25551-25558.

[159] Calvet W, Murugasen E, Klett J, et al. Silicon based tandem cells: novel photocathodes for hydrogen production. Phys Chem Chem Phys. 2014; 16(24): 12043-12050.

[160] Urbain F, Smirnov V, Becker J-P, et al. Application and modeling of an integrated amorphous silicon tandem based device for solar water splitting. Sol Energy Mater Sol Cell. 2015; 140: 275-280.

[161] Jin W, Shin C, Lim S, et al. Natural leaf-inspired solar water splitting system. Appl Catal B Environ. 2023; 322:122086.

[162] Chen L, Wang Z, Kang P. Efficient photoelectrocatalytic CO₂ reduction by cobalt complexes at silicon electrode. Chin J Catal. 2018; 39(3): 413-420.

[163] Hu J, Fan N, Chen C, et al. Facet engineering in Au nanoparticles buried in p-Si photocathodes for enhanced photoelectrochemical CO₂ reduction. Appl Catal B Environ. 2023; 327:122438.

[164] Wang K, Fan N, Xu B, et al. Steering the pathway of plasmon-enhanced photoelectrochemical CO₂ reduction by bridging Si and Au nanoparticles through a TiO₂ interlayer. Small. 2022; 18(20):2201882.

[165] Shan B, Vanka S, Li T-T, et al. Binary molecular-semiconductor p-n junctions for photoelectrocatalytic CO₂ reduction. Nat Energy. 2019; 4(4): 290-299.

[166] Pan Y, Zhang H, Zhang B, et al. Renewable formate from sunlight, biomass and carbon dioxide in a photoelectrochemical cell. Nat Commun. 2023; 14(1):1013.

[167] Liu B, Wang T, Wang S, et al. Back-illuminated photoelectrochemical flow cell for efficient CO₂ reduction. Nat Commun. 2022; 13(1):7111.

[168] Kan M, Yang C, Wang Q, et al. Defect-assisted electron tunneling for photoelectrochemical CO₂ reduction to ethanol at low overpotentials. Adv Energy Mater. 2022; 12(26):2201134.

[169] Li D, Yang K, Lian J, Yan J, Liu S. Powering the world with solar fuels from photoelectrochemical CO₂ reduction: basic principles and recent advances. Adv Energy Mater. 2022; 12(31):2201070.

[170] Zhang X, Lyu Y, Zhou H, et al. Photoelectrochemical N₂-to-NH₃ fixation with high efficiency and rates via optimized Si-based system at positive potential versus Li^0/+. Adv Mater. 2023; 35(21):2211894.

[171] Mao Y, Zhang H, Jiang W, et al. An integrated Si photocathode with lithiation-activated molybdenum oxide nanosheets for efficient ammonia synthesis. Nano Energy. 2022; 102:107639.

[172] Liu D, Peng S, Qiao L, et al. Rational design of cocatalyst for highly improved ammonia production from photoelectrochemical nitrate reduction. Appl Catal B Environ. 2024; 351:123980.

[173] Yang J, Walczak K, Anzenberg E, et al. Efficient and sustained photoelectrochemical water oxidation by cobalt oxide/silicon photoanodes with nanotextured interfaces. J Am Chem Soc. 2014; 136(17): 6191-6194.

[174] Yu X, Yang P, Chen S, Zhang M, Shi G. NiFe alloy protected silicon photoanode for efficient water splitting. Adv Energy Mater. 2017; 7(6):1601805.

[175] Oh S, Song H, Oh J. An optically and electrochemically decoupled monolithic photoelectrochemical cell for high-performance solar-driven water splitting. Nano Lett. 2017; 17(9): 5416-5422.

[176] Guo B, Batool A, Xie G, et al. Facile integration between Si and catalyst for high-performance photoanodes by a multifunctional bridging layer. Nano Lett. 2018; 18(2): 1516-1521.

[177] Kenney MJ, Gong M, Li Y, et al. High-performance silicon photoanodes passivated with ultrathin nickel films for water oxidation. Science. 2013; 342(6160): 836-840.

[178] Yao T, Chen R, Li J, et al. Manipulating the interfacial energetics of n-type silicon photoanode for efficient water oxidation. J Am Chem Soc. 2016; 138(41): 13664-13672.

[179] Zhao J, Gill TM, Zheng X. Enabling silicon photoanodes for efficient solar water splitting by electroless-deposited nickel. Nano Res. 2018; 11(6): 3499-3508.

[180] Li C, Huang M, Zhong Y, Zhang L, Xiao Y, Zhu H. Highly efficient NiFe nanoparticle decorated Si photoanode for photoelectrochemical water oxidation. Chem Mater. 2019; 31(1): 171-178.

[181] Moon C, Alves Martinho FM, Jung G, et al. Dual-purpose tunnel oxide passivated contact on silicon photoelectrodes with high photovoltages for tandem photoelectrochemical devices enabling unassisted water splitting. J Mater Chem A. 2023; 11(8): 4194-4204.

[182] Fan R, Dong W, Fang L, Zheng F, Shen M. More than 10% efficiency and one-week stability of Si photocathodes for water splitting by manipulating the loading of the Pt catalyst and TiO₂ protective layer. J Mater Chem A. 2017; 5(35): 18744-18751.

[183] Li H, Liu B, Feng S, Li H, Wang T, Gong J. Construction of uniform buried pn junctions on pyramid Si photocathodes using a facile and safe spin-on method for photoelectrochemical water splitting. J Mater Chem A. 2020; 8(1): 224-230.

[184] Mei Z, Chen Y, Tong S, et al. High-performance Si photocathode enabled by spatial decoupling multifunctional layers for water splitting. Adv Funct Mater. 2022; 32(2):2107164.

[185] Cheng X, Shen H, Dong W, et al. Nano-Au and ferroelectric polarization mediated Si/ITO/BiFeO₃ tandem photocathode for efficient H₂ production. Adv Mater Interfaces. 2016; 3(19):1600485.

[186] Chen Z, Li Y, Wang L, Bu Y, Ao J-P. Development of a bi-compound heterogeneous cocatalyst modified p-Si photocathode for boosting the photoelectrochemical water splitting performance. J Mater Chem A. 2021; 9(14): 9157-9164.

[187] Labrador NY, Li X, Liu Y, et al. Enhanced performance of Si MIS photocathodes containing oxide-coated nanoparticle electrocatalysts. Nano Lett. 2016; 16(10): 6452-6459.

[188] Sun X, Jiang J, Yang Y, Shan Y, Gong L, Wang M. Enhancing the performance of Si-based photocathodes for solar hydrogen production in alkaline solution by facilely intercalating a sandwich N-doped carbon nanolayer to the interface of Si and TiO₂. ACS Appl Mater Interfaces. 2019; 11(21): 19132-19140.

[189] Li H, Wang T, Liu S, et al. Controllable distribution of oxygen vacancies in grain boundaries of p-Si/TiO₂ heterojunction photocathodes for solar water splitting. Angew Chem Int Ed. 2021; 60(8): 4034-4037.

[190] Yun J, Tan J, Jung Y-K, et al. Interfacial dipole layer enables high-performance heterojunctions for photoelectrochemical water splitting. ACS Energy Lett. 2022; 7(4): 1392-1402.

RIGHTS & PERMISSIONS

2024 The Author(s). EcoEnergy published by John Wiley & Sons Australia, Ltd on behalf of China Chemical Safety Association.