Chemistry, Physics and Technology of Surface

ISSN 2518-1238 (Online), ISSN 2079-1704 (Print)

The use of oxygen modified graphite-like carbon nitride (C₃N₄O_x), photosensitive in the visible region of the optical spectrum, along with TiO₂, photocatalytically active only in the ultraviolet region of the spectrum, in the C₃N₄O_x/TiO₂ binary photocatalyst, opens a possibility of the use of sunlight energy. To increase opportunities of various kinds of photochemistry-related applications of C₃N₄O_x/TiO₂ photocatalyst, the phase composition of the TiO₂ matrix and morphology of nanoparticles of composite and their optical properties are very important. A novel composite material, C₃N₄O_x/TiO₂, was synthesized in the present work in accordance with the approach developed in Frantsevich Institute for Problems of Materials Science of NASU for the synthesis of powdered oxygen-doped carbon nitride (C₃N₄O_x) by CVD method under the special reactionary conditions of the melamine pyrolysis, in particular, in the presence of a fixed air volume. Deposition of C₃N₄O_x carried out on the surface of a nanostructured powdered TiO₂ matrix of different phase composition, rutile or anatase. The deposition of C₃N₄O_x (~5 % O) on both rutile and  anatase nanopowders was confirmed by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis-DRS) methods. SEM micrographs (recorded with a MIRA3 TESCAN scanning electron microscope) of nanoparticles of both C₃N₄O_x/TiO₂ composites (anatase and rutile phases) demonstrate the arrangement of TiO₂ as separate globular nanoparticles and clusters between the plates and in the channels of the porous scaly plates C₃N₄O_x. However, the anatase phase nanoparticles (synthesized in IPM NASU) have a higher dispersion, the average size of non-aggregated almost monodisperse particles is about 10 nm. Using UV/Vis spectroscopy, it has been found that a redshift of long-wavelength edge of the fundamental absorption band of the spectra is observed when going from TiO₂ (anatase), TiO₂ (rutile), C₃N₄, C₃N₄O_x/TiO₂ (anatase), C₃N₄O_x/TiO₂ (rutile) and, then, to C₃N₄O_x, and the band gap decreases from 3.2, 3.0, 2.6, 2.4, 2.25 to 2.1 eV in the above sequence of materials. In such a case, C₃N₄O_x/TiO₂ (especially deposited on anatase phase) would absorb more visible light than g-C₃N₄ and TiO₂, by generating more charges which favor the improvement in the photoactivity of the catalysts.

1. Putri L.K., Ng B.J., Er C.C., Ong W.J., Chang W.S., Mohamed A.R., Chaia S.P. Insights on the impact of doping levels in oxygen-doped gC3N4 and its effects on photocatalytic activity. Appl. Surf. Sci. 2020. 504: 144427. https://doi.org/10.1016/j.apsusc.2019.144427

2. Lei J., Chen B., Lv W., Zhou L., Wang L., Liu Y., Zhang J. Inverse opal TiO₂/g-C3N4 composite with heterojunction construction for enhanced visible light-driven photocatalytic activity. Dalton Trans. 2019. 48(10): 3486. https://doi.org/10.1039/C8DT04496A

3. Zhong R., Zhang Z., Luo S., Zhang Z.C., Huang L., Gu M. Comparison TiO₂ and g-C₃N₄ 2D/2D nanocomposites from three synthesis protocols for visible-light induced hydrogen evolution. Catal. Sci. Technol. 2019. 9(1): 75. https://doi.org/10.1039/C8CY00965A

4. Ovcharov M.L., Shvalagin V.V., Granchak V.M. Photocatalytic reduction of CO₂ on mesoporous TiO2 modified with Ag/Cu bimetallic nanostructures. Theor. Exp. Chem. 2014. 50(3): 175. https://doi.org/10.1007/s11237-014-9362-x

5. Stroyuk A.L., Rayevska O.E., Shvalagin V.V., Kuchmiy S.Ya., Bavykin D.V., Streltsov E.A., Poznyak S.K. Gelatin-templated mesoporous titania for photocatalytic air treatment and application in metal-chalcogenide nanoparticle-sensitized solar cells. Photochem. Photobiol. Sci. 2013. 12(4): 621. https://doi.org/10.1039/C2PP25196E

6. Liu Q., Tian H., Dai Z., Sun H., Liu J., Ao Z., Wang S., Han C., Liu S. Nitrogen-doped carbon nanospheres-modified graphitic carbon nitride with outstanding photocatalytic activity. Nano-Micro Lett. 2020. 12(1): 1. https://doi.org/10.1007/s40820-019-0358-x

7. Wang H., Guan Y., Hu S., Pei Y., Ma W., Fan Z. Hydrothermal synthesis of band gap-tunable oxygen doped g-C3N4 with outstanding "two channel" photocatalytic H₂O₂ production ability assisted by dissolution-precipitation process. Nano. 2019. 14(2): 1950023. https://doi.org/10.1142/S1793292019500231

8. Jiang T., Liu S., Gao Y., Rony A.H., Fan M., Tan G. Surface modification of porous g-C₃N₄ materials by waste product for enhanced photocatalytic performance under visible light. Green Chem. 2019. 21: 5934. https://doi.org/10.1039/C9GC02631B

9. Wen J., Xie J., Chen X., Li X. A review on g-C₃N₄-based photocatalysts. Appl. Surf. Sci. 2017. 391: 72. https://doi.org/10.1016/j.apsusc.2016.07.030

10. Qu X., Hu S., Bai J., Li P., Lu G., Kang X. A facile approach to synthesize oxygen doped g-C₃N₄ with enhanced visible light activity under anoxic conditions via oxygen-plasma treatment. New J. Chem. 2018. 42(7): 4998. https://doi.org/10.1039/C7NJ04760F

11. Liu X., Ji H., Wang J., Xiao J., Yuan H., Xiao D. Ozone treatment of graphitic carbon nitride with enhanced photocatalytic activity under visible light irradiation. J. Colloid Interface Sci. 2017. 505: 919. https://doi.org/10.1016/j.jcis.2017.06.082

12. Wei F., Liu Y., Zhao H., Ren X., Liu J., Hasan T., Chen L., Li Y., Su B. Oxygen self-doped g-C₃N₄ with tunable electronic band structure for unprecedentedly enhanced photocatalytic performance. Nanoscale. 2018. 10(9): 4515. https://doi.org/10.1039/C7NR09660G

13. Li J., Shen B., Hong Z. A facile approach to synthesize novel oxygen-doped g-C₃N₄ with superior visible-light photoreactivity. Chem. Commun. 2012. 48(98): 12017. https://doi.org/10.1039/c2cc35862j

14. Ming L., Yue H., Xu L., Chen F. Hydrothermal synthesis of oxidized g-C₃N₄ and its regulation of photocatalytic activity. J. Mater. Chem. A. 2014. 2(45): 19145.

15. Yang L.Q., Huang J.F., Shi L., Cao L.Y., Yu Q., Jie Y.N., Fei J., Ouyang H.B., Ye J.H. A surface modification resultant thermally oxidized porous g-C₃N₄ with enhanced photocatalytic hydrogen production. Appl. Catal. B. 2017. 204: 335. https://doi.org/10.1016/j.apcatb.2016.11.047

16. Qiu P.X., Xu C.M., Chen H., Fang J., Xin W., Ruifeng L., Xirui Z. One step synthesis of oxygen doped porous graphitic carbon nitride with remarkable improvement of photo-oxidation activity: Role of oxygen on visible light photocatalytic activity. Appl. Catal. B. 2017. 206: 319. https://doi.org/10.1016/j.apcatb.2017.01.058

17. Kharlamov A.I., Kharlamova G.A., Bondarenko M.E. New products of a new method for pyrolysis of pyridine. Russ. J. Appl. Chem. 2013. 86(2): 167. https://doi.org/10.1134/S1070427213020079

18. Kharlamov O., Bondarenko M., Kharlamova G. O-Doped Carbon Nitride (O-g-C₃N) With High Oxygen Content (11.1 mass %) Synthesized by Pyrolysis of Pyridine. In: Nanotechnology to Aid Chemical and Biological Defense, NATO Science for Peace and Security Series A: Chemistry and Biology. V. 9. (Dordrecht: Springer Science+Business Media, 2015). P. 129. https://doi.org/10.1007/978-94-017-7218-1_9

19. Kharlamov A.I., Bondarenko M.E., Kharlamova G.A. New method for synthesis of oxygen-doped graphite-like carbon nitride from pyridine. Russ. J. Appl. Chem. 2014. 87(9): 1284. https://doi.org/10.1134/S107042721409016X

20. Kharlamov A., Bondarenko M., Kharlamova G. Method for the synthesis of water-soluble oxide of graphite-like carbon nitride. Diamond Relat. Mater. 2016. 61: 46. https://doi.org/10.1016/j.diamond.2015.11.006

21. Kharlamov A., Bondarenko M., Kharlamova G., Gubareni N. Features of the synthesis of carbon nitride oxide (g-C3N4)O at urea pyrolysis. Diamond Relat. Mater. 2016. 66: 16. https://doi.org/10.1016/j.diamond.2016.03.012

22. Kharlamov A., Bondarenko M., Kharlamova G., Fomenko V. Synthesis of reduced carbon nitride at the reduction by hydroquinone of water-soluble carbon nitride oxide (g-C₃N₄)O. J. Solid State Chem. 2016. 241: 115. https://doi.org/10.1016/j.jssc.2016.06.003

23. Kharlamov O., Bondarenko M., Kharlamova G., Silenko P., Khyzhun O., Gubareni N. Carbon Nitride Oxide (g-C₃N₄)O and Heteroatomic N-graphene (Azagraphene) as Perspective New Materials in CBRN defense. In: Nanostructured Materials for the Detection of CBRN, NATO Science for Peace and Security Series A: Chemistry and Biology. (Springer, Dordrecht, Chapter, V. 20. 2018). P. 245. https://doi.org/10.1007/978-94-024-1304-5_20

24. Bondarenko M., Silenko P., Gubareni N., Khyzhun O., Ostapovskaya N., Solonin Yu. Synthesis of multilayer azagraphene and carbon nitride oxide. Him. Fiz. Tehnol. Poverhni. 2018. 9(4): 393. https://doi.org/10.15407/hftp09.04.393

25. Bondarenko M., Silenko P., Solonin Yu., Gubareni N., Khyzhun O., Ostapovskaya N. Synthesis O-g-C₃N₄/TiO₂ rutile composite material for photocatalytic application. Him. Fiz. Tehnol. Poverhni. 2019. 10(4): 398.

26. Li H., Wu X., Yin S., Katsumata K., Wang Y. Effect of rutile TiO₂ on the photocatalytic performance of g-C₃N₄/brookite-TiO₂-xNy photocatalyst for NO decomposition. Appl. Surf. Sci. 2017. 392: 531. https://doi.org/10.1016/j.apsusc.2016.09.075

27. Li Y., Lv K., Ho W., Dong F., Wu X., Xia Y. Hybridization of rutile TiO₂ (rTiO₂) with g-C₃N₄ quantum dots (CN QDs): An efficient visible-light-driven Z-scheme hybridized photocatalyst. Appl. Catal. B. 2017. 202: 611. https://doi.org/10.1016/j.apcatb.2016.09.055

28. Liu C., Wang F., Zhang J., Wang K., Qiu Y., Liang Q., Chen Z. Efficient Photoelectrochemical Water Splitting by g-C₃N₄/TiO₂ Nanotube Array Heterostructures. Nano-Micro Lett. 2018. 10: 37. https://doi.org/10.1007/s40820-018-0192-6

29. Xu J., Li Y., Zhou X., Li Y., Gao Z.-D., Song Y.-Y., Schmuki P. Graphitic C₃N₄ sensitized TiO₂ nanotube layers: a visible light activated efficient antimicrobial platform. Chem. Eur. J. 2016. 22(12): 3947. https://doi.org/10.1002/chem.201505173

30. Shalom M., Gimenez S., Schipper F., Herraiz-Cardona I., Bisquert J., Antonietti M. Controlled carbon nitride growth on surfaces for hydrogen evolution electrodes. Angew. Chem. 2014. 53(14): 3654. https://doi.org/10.1002/anie.201309415

31. Boonprakob N, Wetchakun N, Phanichphant S, Waxler D, Sherrell P, Nattestad A, Chen J, Inceesungvorn B. Enhanced visible-light photocatalytic activity of g-C₃N₄/TiO₂ films. J. Colloid Interface Sci. 2014. 1(417): 402. https://doi.org/10.1016/j.jcis.2013.11.072

32. Ren B, Wang T, Qu G, Deng F, Liang D, Yang W, Liu M. In situ synthesis of g-C₃N₄/TiO₂ heterojunction nanocomposites as a highly active photocatalyst for the degradation of Orange II under visible light irradiation. Environ. Sci. Pollut. Res. Int. 2018. 25(19): 19122. https://doi.org/10.1007/s11356-018-2114-z

33. Wang P., Guo X., Rao L., Wang C., Guo Y., Zhang L. A weak-light-responsive TiO₂/g-C₃N₄ composite film: photocatalytic activity under low-intensity light irradiation. Environ Sci. Pollut. Res. Int. 2018. 25(20): 20206. https://doi.org/10.1007/s11356-018-2201-1

34. Kelyp O.O., Petrik I.S., Vorobets V.S., Smirnova N.P., Kolbasov G.Ya. Sol-gel synthesis and characterization of mesoporous TiO₂ modified with transition metal ions (Co, Ni, Mn, Cu). Him. Fiz. Tehnol. Poverhni. 2013. 4(1): 105. https://doi.org/10.15407/hftp04.01.105

35. Chubenko E.B., Denisov N.M., Baglov A.V., Bondarenko V.P., Borisenko V.E. Recovery behavior of the luminescence peak from graphitic carbon nitride as a function of the synthesis temperature. Cryst. Res. Technol. 2020. 55(3): 1900163. https://doi.org/10.1002/crat.201900163

36. Liu S., Li D., Sun H. Ang H.M., Tade M.O., Wang S. Oxygen functional groups in graphitic carbon nitride for enhanced photocatalysis. J. Colloid Interface Sci. 2016. 468: 176. https://doi.org/10.1016/j.jcis.2016.01.051

37. Wang C., Fan H., Ren X., Ma J., Fang J., Wang W. Hydrothermally induced oxygen doping of graphitic carbon nitride with a highly ordered architecture and enhanced photocatalytic activity. Chem. Sus. Chem. 2018. 11(4): 700. https://doi.org/10.1002/cssc.201702278

38. Pankivska Yu.B., Biliavska L.O., Povnitsa O.Yu., Zagornyi M.M., Ragulia A.V., Kharchuk M.S., Zagorodnya S.D. Antiadenoviral activity of titanium dioxide nanoparticles. Mikrobiolohichnyi Zhurnal. 2019. 81(5): 73. https://doi.org/10.15407/microbiolj81.05.073

39. Huang Z.F., Song J., Pan L., Wang Z., Zhang X., Zou J.J. Carbon nitride with simultaneous porous network and O-doping for efficient solar-energy-driven hydrogen evolution. Nano Energy. 2015. 12: 646.

40. Xue J., Fujitsuka M., Majima T. The role of nitrogen defects in graphitic carbon nitride for visible-light-driven hydrogen evolution. Phys. Chem. Chem. Phys. 2019. 21(5): 2318.