Tailoring GaN nanorods with MoS₂ on tungsten foil for enhanced photoelectrochemical performance

Abstract

Gallium nitride (GaN) nanostructures are highly promising for photoelectrochemical (PEC) water splitting due to their excellent electron mobility, chemical stability, and large surface area. However, the wide bandgap (~3.4 eV) of GaN limits its ability to absorb a broad spectrum of solar radiation, restricting its PEC performance. To address this limitation, MoS₂/GaN nanorods (NRs) heterostructures for enhanced PEC applications were fabricated on thin tungsten foil using a combination of atmospheric pressure chemical vapor deposition (CVD) and laser molecular beam epitaxy (LMBE). The Raman spectroscopy and X-ray diffraction revealed the hexagonal phase of GaN and MoS₂. X-ray photoelectron spectroscopy examined the electronic states of the GaN and MoS₂. PEC measurements revealed that the MoS₂-decorated GaN NRs exhibited a photocurrent density of approximately172 µA/cm², nearly 2.5-fold compared to bare GaN NRs (~70 µA/cm²). The increased photocurrent density is ascribed to the Type II band alignment between MoS₂ and GaN, which promotes effective charge separation, the decrease in charge transfer resistance, and the increase in active sites. The findings of this work underscore that the CVD and LMBE technique fabricated MoS₂/GaN heterostructures on W metal foil substrate can provide the vital strategy to raise the PEC efficiency toward solar water splitting.

Graphical abstract

Keywords

GaN nanorods / MoS₂ / X-ray photoelectron spectroscopy / PEC water splitting.

References

[1] Walter M G , Warren E L , McKone J R . . Solar water splitting cells. Chemical Reviews, 2010, 110(11): 6446–6473

[2] Bak T , Nowotny J , Rekas M . . Photo-electrochemical hydrogen generation from water using solar energy. Materials-related aspects. International Journal of Hydrogen Energy, 2002, 27(10): 991–1022

[3] Qu H , Xu X , Hong L . . Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide. Frontiers in Energy, 2024, 18(4): 463–473

[4] Zhang J Z . Metal oxide nanomaterials for solar hydrogen generation from photoelectrochemical water splitting. MRS Bulletin, 2011, 36(1): 48–55

[5] Li Y , Sadaf S M , Zhou B . Ga(X)N/Si nanoarchitecture: An emerging semiconductor platform for sunlight-powered water splitting toward hydrogen. Frontiers in Energy, 2024, 18(1): 56–79

[6] van de Krol R , Liang Y , Schoonman J . Solar hydrogen production with nanostructured metal oxides. Journal of Materials Chemistry, 2008, 18(20): 2311–2320

[7] Landman A , Dotan H , Shter G E . . Photoelectrochemical water splitting in separate oxygen and hydrogen. Nature Materials, 2017, 16(6): 646–651

[8] Sher Shah M S A , Jang G Y , Zhang K . . Transition metal carbide-based nanostructures for electrochemical hydrogen and oxygen evolution reactions. EcoEnergy, 2023, 1(2): 344–374

[9] Tayebi M , Masoumi Z , Seo B . . Efficient and stable MoO_X@Mo-BiVO₄ photoanodes for photoelectrochemical water oxidation: Optimization and understanding. ACS Applied Energy Materials, 2022, 5(9): 11568–11580

[10] Tayebi M , Tayyebi A , Masoumi Z . . Photo corrosion suppression and photoelectrochemical (PEC) enhancement of ZnO via hybridization with graphene nanosheets. Applied Surface Science, 2020, 502: 144189

[11] Omid Najafabadi E , Razi Astaraei F , Tayebi M . . et al. Embedding cobalt polyoxometalate in polypyrrole shell for improved photoelectrochemical performance of BiVO₄ core. Materials Chemistry and Physics, 2023, 309: 128430

[12] Chen P , Ye J , Wang H . . Recent progress of transition metal carbides/nitrides for electrocatalytic water splitting. Journal of Alloys and Compounds, 2021, 883: 160833

[13] Han N , Liu P , Jiang J . . Recent advances in nanostructured metal nitrides for water splitting. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2018, 6(41): 19912–19933

[14] Abdullah A , Bagal I V , Waseem A . . Engineering GaN nanowire photoanode interfaces for efficient and stable photoelectrochemical water splitting. Materials Today Physics, 2022, 28: 100846

[15] Han S , Noh S , Yu Y T . . Highly efficient photoelectrochemical water splitting using gan-nanowire photoanode with tungsten sulfides. ACS Applied Materials & Interfaces, 2020, 12(52): 58028–58037

[16] Noh S , Shin J , Lee J . . Improvement in photoelectrochemical water splitting performance of GaN-nanowire photoanode using mxene. ACS Applied Materials & Interfaces, 2024, 16(6): 8016–8023

[17] Haque F , Daeneke T , Kalantar-zadeh K . . Two-dimensional transition metal oxide and chalcogenide-based photocatalysts. Nano-Micro Letters, 2018, 10(2): 23

[18] Bozheyev F , Ellmer K . Thin film transition metal dichalcogenide photoelectrodes for solar hydrogen evolution: A review. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2022, 10(17): 9327–9347

[19] Singh B , Behera G C , Pradhan B K . . PtSe₂/TiO₂ nanotubes heterostructure for enhanced photo-electrochemical water splitting. Journal of Materials Science, 2024, 59(32): 15201–15220

[20] Khodabandeh F , Abdizadeh H , Golobostanfard M R . Decoration of ZnO nanorod arrays with heterojunction of graphene quantum dots and MoS₂ nanoparticles for photoelectrochemical water splitting. ACS Applied Energy Materials, 2025, 8(1): 170–180

[21] Shen C , Wierzbicka E , Schultz T . . Atomic layer deposition of MoS₂ decorated TiO₂ nanotubes for photoelectrochemical water splitting. Advanced Materials Interfaces, 2022, 9(20): 2200643

[22] Trung T N , Seo D B , Quang N D . . Enhanced photoelectrochemical activity in the heterostructure of vertically aligned few-layer MoS₂ flakes on ZnO. Electrochimica Acta, 2018, 260: 150–156

[23] Seo D B , Kim S , Trung T N . . Conformal growth of few-layer MoS₂ flakes on closely-packed TiO₂ nanowires and their enhanced photoelectrochemical reactivity. Journal of Alloys and Compounds, 2019, 770: 686–691

[24] Seo D B , Trung T N , Kim D O . . Plasmonic Ag-decorated few-layer MoS₂ nanosheets vertically grown on graphene for efficient photoelectrochemical water splitting. Nano-Micro Letters, 2020, 12(1): 172

[25] Seo D B , Dongquoc V , Jayarathna R A . . Rational heterojunction design of 1D WO₃ nanorods decorated with vertical 2D MoS₂ nanosheets for enhanced photoelectrochemical performance. Journal of Alloys and Compounds, 2022, 911: 165090

[26] Trung T N , Van Bay T , Seo D B . . Efficient heterostructure of MoS₂/Ti-doped Fe₂O₃ nanorods for high-performance photoelectrochemical activity. Materials Letters, 2023, 341: 134301

[27] Pesci F M , Sokolikova M S , Grotta C . . MoS₂/WS₂ heterojunction for photoelectrochemical water oxidation. ACS Catalysis, 2017, 7(8): 4990–4998

[28] Tayebi M , Masoumi Z , Lee B K . Ultrasonically prepared photocatalyst of W/WO₃ nanoplates with WS₂ nanosheets as 2D material for improving photoelectrochemical water splitting. Ultrasonics Sonochemistry, 2021, 70: 105339

[29] Hassan M A , Kim M W , Johar M A . . Transferred monolayer MoS₂ onto GaN for heterostructure photoanode: Toward stable and efficient photoelectrochemical water splitting. Scientific Reports, 2019, 9(1): 20141

[30] Zhao H , Fu H , Yang X . . MoS₂/CdS rod-like nanocomposites as high-performance visible light photocatalysts for water splitting photocatalytic hydrogen production. International Journal of Hydrogen Energy, 2022, 47(13): 8247–8260

[31] Sitara E , Nasir H , Mumtaz A . . Efficient photoelectrochemical water splitting by tailoring MoS₂/CoTe heterojunction in a photoelectrochemical cell. Nanomaterials, 2020, 10(12): 2341

[32] Zhou B , Kong X , Vanka S . . Gallium nitride nanowire as a linker of molybdenum sulphides and silicon for photo electrocatalytic water splitting. Nature Communications, 2018, 9(1): 3856

[33] Ghosh D , Devi P , Kumar P . Modified p-GaN microwells with vertically aligned 2D-MoS₂ for enhanced photoelectrochemical water splitting. ACS Applied Materials & Interfaces, 2020, 12(12): 13797–13804

[34] Singh B , Kumar R , Behera G C . . Fabrication of Bi₂Se₃/ZnSe and MoS₂/ZnSe heterojunction photoanodes on Ti foils for enhanced photoelectrochemical water splitting. Materials Science and Engineering B, 2025, 313: 117893

[35] Ramesh Ch , Tyagi P , Aggarwal V . . Hybrid reduced graphene oxide/GaN nanocolumns on flexible niobium foils for efficient photoelectrochemical water splitting. ACS Applied Nano Materials, 2023, 6(3): 1898–1909

[36] Tyagi P , Ramesh Ch , Kaswan J . . Direct growth of self-aligned single-crystalline GaN nanorod array on flexible Ta foil for photocatalytic solar water-splitting. Journal of Alloys and Compounds, 2019, 805: 97–103

[37] Ramesh Ch , Tyagi P , Mauraya A K . . Structural and optical properties of low-temperature-grown single-crystalline GaN nanorods on flexible tungsten foil using laser molecular beam epitaxy. Materials Research Express, 2019, 6(8): 085919

[38] Abdullah Q N , Yam F K , Hassan J J . . High-performance room temperature GaN-nanowires hydrogen gas sensor fabricated by chemical vapor deposition (CVD) technique. International Journal of Hydrogen Energy, 2013, 38(32): 14085–14101

[39] Aggarwal V , Ramesh Ch , Varshney U . . Correlation of crystalline and optical properties with UV photodetector characteristics of GaN grown by laser molecular beam epitaxy on a-sapphire. Applied Physics. A, Materials Science & Processing, 2022, 128(11): 989

[40] Singh B , Gautam S , Behera G C . . MoS₂ thin film decorated TiO₂ nanotube arrays on flexible Ti foil for solar water splitting application. Nano Express, 2024, 5(1): 015006

[41] Xiao S , Xiao P , Zhang X . . Atomic-layer soft plasma etching of MoS₂. Scientific Reports, 2016, 6(1): 19945

[42] Huang Y F , Liao K W , Fahmi F R Z . . Thickness dependent photocatalysis of ultra-thin MoS₂ film for visible light-driven CO₂ reduction. Catalysts, 2021, 11(11): 1295

[43] Hao J , Xu S , Gao B . . PL tunable GaN nanoparticles synthesis through femtosecond pulsed laser ablation in different environments. Nanomaterials, 2020, 10(3): 439

[44] Kang B K , Song Y H , Kang S M . . Formation of highly efficient dye-sensitized solar cells by effective electron injection with GaN nanoparticles. Journal of the Electrochemical Society, 2011, 158(7): H693–H696

[45] Grodzicki M . Properties of bare and thin-film-covered GaN (0001) surfaces. Coatings, 2021, 11(2): 145

[46] Ramesh Ch , Tyagi P , Kaswan J . . Effect of surface modification and laser repetition rate on growth, structural, electronic, and optical properties of GaN nanorods on flexible Ti metal foil. RSC Advances, 2020, 10(4): 2113–2122

[47] Gupta N , Singh B , Gautam S . . Low-temperature growth of MoSe₂ and WSe₂ nanostructures on flexible Mo and W metal foils. Bulletin of Materials Science, 2024, 47(3): 120

[48] Ghasemi F , Mohajerzadeh S A . Sequential solvent exchange method for controlled exfoliation of MoS₂ suitable for phototransistor fabrication. ACS Applied Materials & Interfaces, 2016, 8(45): 31179–31191

[49] Lai B , Singh S C , Bindra J K . . Hydrogen evolution reaction from bare and surface-functionalized few-layered MoS₂ nanosheets in acidic and alkaline electrolytes. Materials Today. Chemistry, 2019, 14: 100207

[50] Pal D , Maity D , Sarkar A . . Effect of defect-rich Co-CeO_x OER cocatalyst on the photocarrier dynamics and electronic structure of Sb-doped TiO₂ nanorods photoanode. Journal of Colloid and Interface Science, 2022, 620: 209–220

[51] Sanke D M , Ghosh N G , Das S . . Localized surface plasmon-enhanced photoelectrochemical water oxidation by inorganic/organic nano-heterostructure comprising NDI-based DAD-type small molecule. Journal of Colloid and Interface Science, 2021, 601: 803–815

[52] Li Y , Xu C Y , Zhen L . Surface potential and interlayer screening effects of few-layer MoS₂ nanoflakes. Applied Physics Letters, 2013, 102(14): 143110

[53] Karmakar H S , Sarkar A , Ghosh N G . . Pt nanoparticles coupled with perylene-based small molecule deposited on Ti³⁺ self-doped TiO₂ nanorods, an inorganic/organic type-II nano heterostructure for efficient visible-light photoelectrochemical water oxidation. Chemosphere, 2022, 301: 134696

[54] Sanke D M , Sarkar A , Das S . . Iron-doped TiO₂ nanorods coupled with naphthalenediimide (NDI) and 3,4-ethylenedioxythiophene (EDOT)-based donor-acceptor-donor type small organic molecule for visible-light water oxidation. Materials Today. Chemistry, 2023, 33: 101699

[55] Tayebi M , Masoumi Z , Kolaei M . . Highly efficient and stable WO₃/MoS₂-MoOX photoanode for photoelectrochemical hydrogen production; a collaborative approach of facet engineering and PN junction. Chemical Engineering Journal, 2022, 446: 136830

[56] Pal D , Maity D , Sarkar A . . Multifunctional ultrathin amorphous CoFe-Prussian blue analogue catalysts for efficiently boosting the oxygen evolution activity of antimony-doped TiO₂ nanorods photoanode. ACS Applied Energy Materials, 2022, 5(12): 15000–15009

[57] Zhao Y F , Yang Z Y , Zhang Y X . . Cu₂O decorated with cocatalyst MoS₂ for solar hydrogen production with enhanced efficiency under visible light. Journal of Physical Chemistry C, 2014, 118(26): 14238–14245

[58] Ye L , Zhang H , Xiong Y . . Efficient photoelectrochemical overall water-splitting of MoS₂/g-C₃N₄ n-n type heterojunction film. Journal of Chemical Physics, 2021, 154(21): 214701

[59] Lee M G , Yang J W , Park H . . Crystal facet engineering of TiO₂ nanostructures for enhancing photoelectrochemical water splitting with BiVO₄ nanodots. Nano-Micro Letters, 2022, 14(1): 48

[60] Thomas N , Mathew S , Nair K M . . 2D MoS₂: Structure, mechanisms, and photocatalytic applications. Materials Today Sustainability, 2021, 13: 100073

[61] Desai P , Ranade A K , Shinde M . . Growth of uniform MoS₂ layers on free-standing GaN semiconductor for vertical heterojunction device application. Journal of Materials Science Materials in Electronics, 2020, 31(3): 2040–2048

[62] Purwiandono G , Manseki K , Sugiura T . Photo-electrochemical property of 2D hexagonal-shape GaN nanoplates synthesized using solid nitrogen source in molten salt. Journal of Photochemistry and Photobiology A Chemistry, 2020, 394: 112499

[63] Lancry O , Farvacque J L , Pichonat E . . Indirect interband transition in hexagonal GaN. Journal of Physics. D, Applied Physics, 2011, 44(7): 075105

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