Plasma-exfoliated g-C₃N₄ with oxygen doping: tailoring photocatalytic properties

Abstract

Heteroatom doping and defect engineering have been proposed as effective ways to modulate the energy band structure and improve the photocatalytic activity of g-C₃N₄. In this work, ultrathin defective g-C₃N₄ was successfully prepared using cold plasma. Plasma exfoliation reduces the thickness of g-C₃N₄ from 10 nm to 3 nm, while simultaneously introducing a large number of nitrogen defects and oxygen atoms into g-C₃N₄. The amount of doped O was regulated by varying the time and power of the plasma treatment. Due to N vacancies, O atoms formed strong bonds with C atoms, resulting in O doping in g-C₃N₄. The mechanism of plasma treatment involves oxygen etching and gas expansion. Photocatalytic experiments demonstrated that appropriate amount of O doping improved the photocatalytic degradation of rhodamine B compared with pure g-C₃N₄. The introduction of O optimized the energy band structure and photoelectric properties of g-C₃N₄. Active species trapping experiments revealed ·O₂^– as the main active species during the degradation.

Graphical abstract

Keywords

graphitic carbon nitride / cold plasma / oxygen doping / nitrogen defect / visible-light photocatalysis

References

[1] Xu C P , Anusuyadevi P R , Aymonier C , Luque R , Marre S . Nanostructured materials for photocatalysis. Chemical Society Reviews, 2019, 48(14): 3868–3902

[2] Wang Z , Li C , Domen K . Recent developments in heterogeneous photocatalysts for solar-driven overall water splitting. Chemical Society Reviews, 2019, 48(7): 2109–2125

[3] Kou J H , Lu C H , Wang J , Chen Y K , Xu Z Z , Varma R S . Selectivity enhancement in heterogeneous photocatalytic transformations. Chemical Reviews, 2017, 117(3): 1445–1514

[4] Ajmal Z , Hayat A , Qasim M , Kumar A , El Jery A , Abbas W , Hussain M B , Qadeer A , Iqbal S , Bashir S . . Assembly of a novel Fe₂TiO₅-impregnated donor-n-acceptor conjugated carbon nitride for highly efficient solar water splitting. Sustainable Materials and Technologies, 2023, 36: e00594

[5] Xia P F , Cao S W , Zhu B C , Liu M J , Shi M S , Yu J G , Zhang Y F . Designing a 0D/2D S-scheme heterojunction over polymeric carbon nitride for visible-light photocatalytic inactivation of bacteria. Angewandte Chemie International Edition, 2020, 59(13): 5218–5225

[6] Nasir M S , Yang G R , Ayub I , Wang S , Wang L , Wang X J , Yan W , Peng S J , Ramakarishna S . Recent development in graphitic carbon nitride based photocatalysis for hydrogen generation. Applied Catalysis B: Environmental, 2019, 257: 117855

[7] Dong G P , Zhang Y H , Pan Q W , Qiu J R . A fantastic graphitic carbon nitride (g-C₃N₄) material: electronic structure, photocatalytic and photoelectronic properties. Journal of Photochemistry and Photobiology C, Photochemistry Reviews, 2014, 20: 33–50

[8] Liu B Y , Du J Y , Ke G L , Jia B , Huang Y J , He H C , Zhou Y , Zou Z G . Boosting O₂ reduction and H₂O dehydrogenation kinetics: surface N-hydroxymethylation of g-C₃N₄ photocatalysts for the efficient production of H₂O₂. Advanced Functional Materials, 2022, 32(15): 2111125

[9] Wang X C , Maeda K , Thomas A , Takanabe K , Xin G , Carlsson J M , Domen K , Antonietti M . A metal-free polymeric photocatalyst for hydrogen production from water under visible light. Nature Materials, 2009, 8(1): 76–80

[10] Liao G F , Gong Y , Zhang L , Gao H Y , Yang G J , Fang B Z . Semiconductor polymeric graphitic carbon nitride photocatalysts: the “holy grail” for the photocatalytic hydrogen evolution reaction under visible light. Energy & Environmental Science, 2019, 12(7): 2080–2147

[11] Cao Q , Kumru B , Antonietti M , Schmidt B . Graphitic carbon nitride and polymers: a mutual combination for advanced properties. Materials Horizons, 2020, 7(3): 762–786

[12] Wang Y , Wang X C , Antonietti M . Polymeric graphitic carbon nitride as a heterogeneous organocatalyst: from photochemistry to multipurpose catalysis to sustainable chemistry. Angewandte Chemie International Edition, 2012, 51(1): 68–89

[13] Zhu J J , Xiao P , Li H L , Carabineiro S A C . Graphitic carbon nitride: synthesis, properties, and applications in catalysis. ACS Applied Materials & Interfaces, 2014, 6(19): 16449–16465

[14] Wang J L , Wang S Z . A critical review on graphitic carbon nitride (g-C₃N₄)-based materials: preparation, modification and environmental application. Coordination Chemistry Reviews, 2022, 453: 214338

[15] Hasija V , Raizada P , Sudhaik A , Sharma K , Kumar A , Singh P , Jonnalagadda S B , Thakur V K . Recent advances in noble metal free doped graphitic carbon nitride based nanohybrids for photocatalysis of organic contaminants in water: a review. Applied Materials Today, 2019, 15: 494–524

[16] Jiang L B , Yuan X Z , Pan Y , Liang J , Zeng G M , Wu Z B , Wang H . Doping of graphitic carbon nitride for photocatalysis: a reveiw. Applied Catalysis B: Environmental, 2017, 217: 388–406

[17] Liu T , Zhu W , Wang N , Zhang K Y , Wen X , Xing Y , Li Y F . Preparation of structure vacancy defect modified diatomic-layered g-C₃N₄ nanosheet with enhanced photocatalytic performance. Advanced Science, 2023, 10(24): 2302503

[18] Liu X Q , Kang W , Zeng W , Zhang Y X , Qi L , Ling F L , Fang L , Chen Q , Zhou M . Structural, electronic and photocatalytic properties of g-C₃N₄ with intrinsic defects: a first-principles hybrid functional investigation. Applied Surface Science, 2020, 499: 143994

[19] Bie C B , Cheng B , Fan J J , Ho W K , Yu J G . Enhanced solar-to-chemical energy conversion of graphitic carbon nitride by two-dimensional cocatalysts. EnergyChem, 2021, 3(2): 100051

[20] Ghosh U , Majumdar A , Pal A . Photocatalytic CO₂ reduction over g-C₃N₄ based heterostructures: recent progress and prospects. Journal of Environmental Chemical Engineering, 2021, 9(1): 104631

[21] Cheng C , Mao L H , Kang X , Dong C L , Huang Y C , Shen S H , Shi J W , Guo L J . A high-cyano groups-content amorphous-crystalline carbon nitride isotype heterojunction photocatalyst for high-quantum-yield H₂ production and enhanced CO₂ reduction. Applied Catalysis B: Environmental, 2023, 331: 122733

[22] Barrio J , Shalom M . Ultralong nanostructured carbon nitride wires and self-standing C-rich filters from supramolecular microspheres. ACS Applied Materials & Interfaces, 2018, 10(46): 39688–39694

[23] Chen Y , Ding F , Khaing A , Yang D , Jiang Z Y . Acetic acid-assisted supramolecular assembly synthesis of porous g-C₃N₄ hexagonal prism with excellent photocatalytic activity. Applied Surface Science, 2019, 479: 757–764

[24] Wu C Z , Xue S Y , Qin Z J , Nazari M , Yang G , Yue S , Tong T , Ghasemi H , Hernandez F C R , Xue S C . . Making g-C₃N₄ ultra-thin nanosheets active for photocatalytic overall water splitting. Applied Catalysis B: Environmental, 2021, 282: 119557

[25] Shen R C , Zhang L , Li N , Lou Z Z , Ma T Y , Zhang P , Li Y J , Li X . W–N bonds precisely boost Z-scheme interfacial charge transfer in g-C₃N₄/WO₃ heterojunctions for enhanced photocatalytic H₂ evolution. ACS Catalysis, 2022, 12(16): 9994–10003

[26] Zhang X Y , Yang G , Meng J Q , Qin L , Ren M , Pan Y , Yang Y X , Guo Y H . Acetamide- or aormamide-assisted in situ approach to carbon-rich or nitrogen-deficient graphitic carbon nitride for notably enhanced visible-light photocatalytic redox performance. Small, 2023, 19(24): 2208012

[27] Zhu D D , Zhou Q X . Nitrogen doped g-C₃N₄ with the extremely narrow band gap for excellent photocatalytic activities under visible light. Applied Catalysis B: Environmental, 2021, 281: 119474

[28] Sun S D , Li J , Cui J , Gou X F , Yang Q , Liang S H , Yang Z M , Zhang J M . Constructing oxygen-doped g-C₃N₄ nanosheets with an enlarged conductive band edge for enhanced visible-light-driven hydrogen evolution. Inorganic Chemistry Frontiers, 2018, 5(7): 1721–1727

[29] Xia X , Xie C , Xu B G , Ji X S , Gao G G , Yang P . Role of B-doping in g-C₃N₄ nanosheets for enhanced photocatalytic NO removal and H₂ generation. Journal of Industrial and Engineering Chemistry, 2022, 105: 303–312

[30] Duan L Y , Li G Q , Zhang S T , Wang H Y , Zhao Y L , Zhang Y F . Preparation of S-doped g-C₃N₄ with C vacancies using the desulfurized waste liquid extracting salt and its application for NO_x removal. Chemical Engineering Journal, 2021, 411: 128551

[31] Wu F , Ma Y L , Hu Y H . Near infrared light-driven photoelectrocatalytic water splitting over P-doped g-C₃N₄. ACS Applied Energy Materials, 2020, 3(11): 11223–11230

[32] Ding Y , Maitra S , Wang C H , Zheng R T , Zhang M Y , Barakat T , Roy S , Liu J , Li Y , Hasan T . . Hydrophilic bi-functional B-doped g-C₃N₄ hierarchical architecture for excellent photocatalytic H₂O₂ production and photoelectrochemical water splitting. Journal of Energy Chemistry, 2022, 70: 236–247

[33] Wang Z , Zhang Y , Neyts E C , Cao X X , Zhang X S , Jang B W L , Liu C J . Catalyst preparation with plasmas: How does it work?. ACS Catalysis, 2018, 8(3): 2093–2110

[34] Huang B J , Tian F , Shen Y D , Zheng M R , Zhao Y S , Wu J , Liu Y , Pennycook S J , Thong J T L . Selective engineering of chalcogen defects in MoS₂ by low-energy helium plasma. ACS Applied Materials & Interfaces, 2019, 11(27): 24404–24411

[35] Bharti B , Kumar S , Lee H N , Kumar R . Formation of oxygen vacancies and Ti³⁺ state in TiO₂ thin film and enhanced optical properties by air plasma treatment. Scientific Reports, 2016, 6(1): 32355

[36] Azcatl A , Qin X Y , Prakash A , Zhang C X , Cheng L X , Wang Q X , Lu N , Kim M J , Kim J , Cho K . . Covalent nitrogen doping and compressive strain in MoS₂ by remote N₂ plasma exposure. Nano Letters, 2016, 16(9): 5437–5443

[37] Akada K , Obata S , Saiki K . Radio-frequency plasma assisted reduction and nitrogen doping of graphene oxide. Carbon, 2022, 189: 571–578

[38] Zhang J N , Ji L Y , Gong J B , Wang Z . Facile synthesis of multiphase cobalt-iron spinel with enriched oxygen vacancies as a bifunctional oxygen electrocatalyst. Physical Chemistry Chemical Physics, 2022, 24(22): 13839–13847

[39] Lu X L , Xu K , Chen P Z , Jia K C , Liu S , Wu C Z . Facile one step method realizing scalable production of g-C₃N₄ nanosheets and study of their photocatalytic H₂ evolution activity. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2014, 2(44): 18924–18928

[40] Zhang D , Guo Y L , Zhao Z K . Porous defect-modified graphitic carbon nitride via a facile one-step approach with significantly enhanced photocatalytic hydrogen evolution under visible light irradiation. Applied Catalysis B: Environmental, 2018, 226: 1–9

[41] Luo Z , Tian S S , Wang Z . Enhanced activity of Cu/ZnO/C catalysts prepared by cold plasma for CO₂ hydrogenation to methanol. Industrial & Engineering Chemistry Research, 2020, 59(13): 5657–5663

[42] Zhang B , Peng X F , Wang Z . Noble metal-free TiO₂-coated carbon nitride layers for enhanced visible light-driven photocatalysis. Nanomaterials, 2020, 10(4): 805

[43] Zhang J , Chen J W , Wan Y F , Liu H W , Chen W , Wang G , Wang R L . Defect engineering in atomic-layered graphitic carbon nitride for greatly extended visible-light photocatalytic hydrogen evolution. ACS Applied Materials & Interfaces, 2020, 12(12): 13805–13812

[44] Chen J A , Fu X Y , Chen H , Wang Z . Simultaneous Gd₂O₃ clusters decoration and O-doping of g-C₃N₄ by solvothermal-polycondensation method for reinforced photocatalytic activity towards sulfamerazine. Journal of Hazardous Materials, 2021, 402: 123780

[45] Wang X Y , Sang L B , Zhang L , Yang G , Guo Y H , Yang Y X . Controllable synthesis for carbon self-doping and structural defect co-modified g-C₃N₄: enhanced photocatalytic oxidation performance and the mechanism insight. Journal of Alloys and Compounds, 2023, 941: 168921

[46] Yang S B , Gong Y J , Zhang J S , Zhan L , Ma L L , Fang Z Y , Vajtai R , Wang X C , Ajayan P M . Exfoliated graphitic carbon nitride nanosheets as efficient catalysts for hydrogen evolution under visible light. Advanced Materials, 2013, 25(17): 2452–2456

[47] Yang X X , Sun J D , Sheng L N , Wang Z Y , Ye Y L , Zheng J Y , Fan M H , Zhang Y Z , Sun X L . Carbon dots cooperatively modulating photocatalytic performance and surface charge of O-doped g-C₃N₄ for efficient water disinfection. Journal of Colloid and Interface Science, 2023, 631: 25–34

[48] Mohamed H S H , Wu L , Li C F , Hu Z Y , Liu J , Deng Z , Chen L H , Li Y , Su B L . In-situ growing mesoporous CuO/O-doped g-C₃N₄ nanospheres for highly enhanced lithium storage. ACS Applied Materials & Interfaces, 2019, 11(36): 32957–32968

[49] Zhu B C , Zhang L Y , Cheng B , Yu J G . First-principle calculation study of tri-s-triazine-based g-C₃N₄: a review. Applied Catalysis B: Environmental, 2018, 224: 983–999

[50] Qaraah F A , Mahyoub S A , Hezam A , Drmosh Q A , Munyaneza J , Yu Q , Xiu G L . One step-polymerization for constructing 1D/2D oxygen doped g-C₃N₄ isotype heterojunctions with highly improved visible-light-driven photocatalytic activity. Journal of Environmental Chemical Engineering, 2021, 9(6): 106587

[51] Zheng Y M , Liu Y Y , Guo X L , Chen Z T , Zhang W J , Wang Y X , Tang X , Zhang Y , Zhao Y H . Sulfur-doped g-C₃N₄/rGO porous nanosheets for highly efficient photocatalytic degradation of refractory contaminants. Journal of Materials Science and Technology, 2020, 41: 117–126

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