TiO₂/g-C₃N₄ heterojunctions: In situ fabrication mechanism and enhanced photocatalytic activity

Abstract

In situ fabrication of TiO₂/g-C₃N₄ (TCN) heterojunctions was achieved by a modified sol–gel method. TG analysis was employed to determine the content of TiO₂ in TCN composites. XRD, FTIR, TEM and HRTEM were used to analyze the phase composition, functional groups, morphology and microstructure of as-obtained products, respectively. Based on the measurement of surface Zeta potential of g-C₃N₄, a possible mechanism on in situ fabrication of TCN heterojunctions was concluded. The control experiments indicated that TCN heterojunctions exhibited better photocatalytic performance than either TiO₂ or g-C₃N₄, suggesting that the enchanced photocatalytic activity could be realized by TCN heterojunctions. Then, the evaluation of parameters affecting the photocatalytic performance of TCN heterojunctions was investigated. Even after five cycles, TCN heterojunctions still maintained high photocatalytic activity, exhibiting the good photocatalytic stability. UV-vis absorption spectra showed that almost all MB molecules were decomposed in the photocatalytic process. Finally, the possible mechanism on enhanced photocatalytic performance of TCN heterojunctions was discussed.

Keywords

TiO₂ / g-C₃N₄ / heterojunctions / photocatalytic mechanism

References

[1] Reddy P A K, Reddy P V L, Kwon E, . Recent advances in photocatalytic treatment of pollutants in aqueous media. Environment International, 2016, 91: 94–103

[2] Ivanov S, Barylyak A, Besaha K, . Synthesis, characterization, and photocatalytic properties of sulfur- and carbon-codoped TiO₂ nanoparticles. Nanoscale Research Letters, 2016, 11(1): 140

[3] Grabowska E. Selected perovskite oxides: Characterization, preparation and photocatalytic properties — A review. Applied Catalysis B: Environmental, 2016, 186: 97–126

[4] Ni Z L, Sun Y J, Zhang Y X, . Fabrication, modification and application of (BiO)₂CO₃-based photocatalysts: A review. Applied Surface Science, 2016, 365: 314–335

[5] He R A, Cao S W, Zhou P, . Recent advances in visible light Bi-based photocatalysts. Chinese Journal of Catalysis, 2014, 35(7): 989–1007

[6] Pan C S, Takata T, Domen K. Overall water splitting on the transition-metal oxynitride photocatalyst LaMg_1/3Ta_2/3O₂N over a large portion of the visible-light spectrum. Chemistry, 2016, 22(5): 1854–1862

[7] Jing P P, Li J N, Pan L N, . Efficient photocatalytic degradation of acid fuchsin in aqueous solution using separate porous tetragonal-CuFe₂O₄ nanotubes. Journal of Hazardous Materials, 2015, 284: 163–170

[8] Jin C, Qin Y, Yang J H. Novel non-TiO₂ semiconductor photocatalysts. Progress in Chemistry, 2014, 26: 225–233

[9] Wang S B, Pan L, Song J J, . Titanium-defected undoped anatase TiO₂ with p-type conductivity, room-temperature ferromagnetism, and remarkable photocatalytic performance. Journal of the American Chemical Society, 2015, 137(8): 2975–2983

[10] Dhabbe R, Kadam A, Korake P, . Synthesis and enhanced photocatalytic activity of Zr-doped N-TiO₂ nanostructures. Journal of Materials Science: Materials in Electronics, 2015, 26(1): 554–563

[11] Ghosh S, Das A P. Modified titanium oxide (TiO₂) nanocomposites and its array of applications: a review. Toxicological and Environmental Chemistry, 2015, 97(5): 491–514

[12] Sajan C P, Wageh S, Al-Ghamdi A A, . TiO₂ nanosheets with exposed {001} facets for photocatalytic applications. Nano Research, 2016, 9(1): 3–27

[13] Zhang N, Xu Y J. The endeavour to advance graphene-semiconductor composite-based photocatalysis. CrystEngComm, 2016, 18(1): 24–37

[14] Wang S B, Pan L, Song J J, . Titanium-defected undoped anatase TiO₂ with p-type conductivity, room-temperature ferromagnetism, and remarkable photocatalytic performance. Journal of the American Chemical Society, 2015, 137(8): 2975–2983

[15] Li H F, Yu H T, Quan X, . Improved photocatalytic performance of heterojunction by controlling the contact facet: high electron transfer capacity between TiO₂ and the {110} facet of BiVO₄ caused by suitable energy band alignment. Advanced Functional Materials, 2015, 25(20): 3074–3080

[16] Xu L, Huang W Q, Wang L L, . Insights into enhanced visible-light photocatalytic hydrogen evolution of g-C₃N₄ and highly reduced graphene oxide composite: the role of oxygen. Chemistry of Materials, 2015, 27(5): 1612–1621

[17] Bai Y, Wang P Q, Liu J Y, . Enhanced photocatalytic performance of direct Z-scheme BiOCl-g-C₃N₄ photocatalysts. RSC Advances, 2014, 4(37): 19456–19461

[18] Huang Z F, Song J J, Pan L, . Carbon nitride with simultaneous porous network and O-doping for efficient solar-energy-driven hydrogen evolution. Nano Energy, 2015, 12: 646–656

[19] Chen Z H, Sun P, Fan B, . In situ template-free ion-exchange process to prepare visible-light-active g-C₃N₄/NiS hybrid photocatalysts with enhanced hydrogen evolution activity. The Journal of Physical Chemistry C, 2014, 118(15): 7801–7807

[20] Jin D Q, Xu Q, Wang Y J, . A derivative photoelectrochemical sensing platform for herbicide acetochlor based on TiO₂-poly (3-hexylthiophene)-ionic liquid nanocomposite film modified electrodes. Talanta, 2014, 127: 169–174

[21] Li H, Zhou L, Wang L Z, . In situ growth of TiO₂ nanocrystals on g-C₃N₄ for enhanced photocatalytic performance. Physical Chemistry Chemical Physics, 2015, 17(26): 17406–17412

[22] Li K, Gao S M, Wang Q Y, . In-situ-reduced synthesis of Ti³⁺ self-doped TiO₂/g-C₃N₄ heterojunctions with high photocatalytic performance under LED light irradiation. ACS Applied Materials & Interfaces, 2015, 7(17): 9023–9030

[23] Xu H Y, Wu L C, Zhao H, . Synergic effect between adsorption and photocatalysis of metal-free g-C₃N₄ derived from different precursors. PLoS ONE, 2015, 10(11): e0142616

[24] Wang X J, Yang W Y, Li F T, . In situ microwave-assisted synthesis of porous N-TiO₂/g-C₃N₄ heterojunctions with enhanced visible-light photocatalytic properties. Industrial & Engineering Chemistry Research, 2013, 52(48): 17140–17150

[25] Lee T Y, Kim H S, Park N G. Evaluation of limiting factors affecting photovoltaic performance of low-temperature-processed TiO₂ films in dye-sensitized solar cells. ChemPhysChem, 2014, 15(6): 1098–1105

[26] Long B H, Lin J L, Wang X C. Thermally-induced desulfurization and conversion of guanidine thiocyanate into graphitic carbon nitride catalysts for hydrogen photosynthesis. Journal of Materials Chemistry A: Materials for Energy and Sustainability, 2014, 2(9): 2942–2951

[27] Zhao H X, Yu H T, Quan X, . Fabrication of atomic single layer graphitic-C₃N₄ and its high performance of photocatalytic disinfection under visible light irradiation. Applied Catalysis B: Environmental, 2014, 152–153: 46–50

[28] Li Y B, Zhang H M, Liu P, . Cross-linked g-C₃N₄/rGO nanocomposites with tunable band structure and enhanced visible light photocatalytic activity. Small, 2013, 9: 3336–3344

[29] Yu J G, Su Y R, Cheng B, . Effects of pH on the microstructures and photocatalytic activity of mesoporous nanocrystalline titania powders prepared via hydrothermal method. Journal of Molecular Catalysis A: Chemical, 2006, 258(1–2): 104–112

[30] Yu J G, Yu H G, Cheng B, . The effect of calcination temperature on the surface microstructure and photocatalytic activity of TiO₂ thin films prepared by liquid phase deposition. The Journal of Physical Chemistry B, 2003, 107(50): 13871–13879

[31] Cui Y J, Ding Z X, Liu P, . Metal-free activation of H₂O₂ by g-C₃N₄ under visible light irradiation for the degradation of organic pollutants. Physical Chemistry Chemical Physics, 2012, 14(4): 1455–1462

[32] Samanta S, Martha S, Parida K. Facile synthesis of Au/g-C₃N₄ nanocomposites: an inorganic/organic hybrid plasmonic photocatalyst with enhanced hydrogen gas evolution under visible-light irradiation. ChemCatChem, 2014, 6: 1453–1462

[33] Liao G Z, Chen S, Quan X, . Graphene oxide modified g-C₃N₄ hybrid with enhanced photocatalytic capability under visible light irradiation. Journal of Materials Chemistry, 2012, 22(6): 2721–2726

[34] Bu X Z, Wu B Z, Long T, . Preparation, characterization and enhancement of the visible-light photocatalytic activity of In₂O₃/rectorite composite. Journal of Alloys and Compounds, 2014, 586: 202–207

[35] Akpan U G, Hameed B H. Parameters affecting the photocatalytic degradation of dyes using TiO₂-based photocatalysts: a review. Journal of Hazardous Materials, 2009, 170(2–3): 520–529

[36] Ge L, Han C C, Liu J. Novel visible light-induced g-C₃N₄/Bi₂WO₆ composite photocatalysts for efficient degradation of methyl orange. Applied Catalysis B: Environmental, 2011, 108– 109: 100–107

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag Berlin Heidelberg