Direct electrospinning method for the construction of Z-scheme TiO2/g-C3N4/RGO ternary heterojunction photocatalysts with remarkably ameliorated photocatalytic performance
Abstract:A series of Z-scheme TiO2/g-C3N4/RGO ternary heterojunction photocatalysts are successfully constructed via a direct electrospinning technique coupled with an annealing process for the first time. They are investigated comprehensively in terms of crystal structure, morphology, composition, specific surface area, photoelectrochemical properties, photodegradation performance, etc. Compared with binary TiO2/g-C3N4 and single-component photocatalysts, ternary heterojunction photocatalysts show the best photodegrad… Show more
“…Notably, compared with those of pure Nb 2 O 5 NFs, the Nb 3d and O 1s peaks of g-C 3 N 4 /Nb 2 O 5 heterojunction shifted slightly to higher energies, evidencing the intense interaction between the Nb 2 O 5 and g-C 3 N 4 that resulted from the formation of effective heterojunction. These phenomena are in good agreement with previous report 53 . Figure 4 ( a ) XPS survey spectrum and high resolution XPS spectra of ( b ) C 1s, ( c ) N 1s, ( d ) Nb 3d and ( e ) O 1s in g-C 3 N 4 /Nb 2 O 5 heterojunction.…”
Section: Resultssupporting
confidence: 94%
“…Such line/area contact increased porosity-related characteristics of the heterojunction and resulted in less agglomeration. In particular, such heterojunction formed by nanofiber and nanosheet can enhance the transport of charges and reduce the recombination probability of photoexcited charge carriers, ultimately further improve the photodegradation efficiency 53 . TEM image (Fig.…”
In this study, graphitic carbon nitride (g-C3N4) and niobium pentoxide nanofibers (Nb2O5 NFs) heterojunction was prepared by means of a direct electrospinning approach combined with calcination process. The characterizations confirmed a well-defined morphology of the g-C3N4/Nb2O5 heterojunction in which Nb2O5 NFs were tightly attached onto g-C3N4 nanosheets. Compared to pure g-C3N4 and Nb2O5 NFs, the as-prepared g-C3N4/Nb2O5 heterojunction exhibited remarkably enhanced photocatalytic activity for degradation of rhodamine B and phenol under visible light irradiation. The enhanced catalytic activity was attributed predominantly to the synergistic effect between g-C3N4 sheets and Nb2O5 NFs, which promoted the transferring of carriers and prohibited their recombination, confirmed by the measurement of transient photocurrent responses and photoluminescence spectra. In addition, the active species trapping experiments indicated that superoxide radical anion (Ā·O2ā) and hole (h+) were the major active species contributing to the photocatalytic process. With its high efficacy and ease of preparation, g-C3N4/Nb2O5 heterojunction has great potentials for applications in treatment of organic pollutants and conversion of solar energy.
“…Notably, compared with those of pure Nb 2 O 5 NFs, the Nb 3d and O 1s peaks of g-C 3 N 4 /Nb 2 O 5 heterojunction shifted slightly to higher energies, evidencing the intense interaction between the Nb 2 O 5 and g-C 3 N 4 that resulted from the formation of effective heterojunction. These phenomena are in good agreement with previous report 53 . Figure 4 ( a ) XPS survey spectrum and high resolution XPS spectra of ( b ) C 1s, ( c ) N 1s, ( d ) Nb 3d and ( e ) O 1s in g-C 3 N 4 /Nb 2 O 5 heterojunction.…”
Section: Resultssupporting
confidence: 94%
“…Such line/area contact increased porosity-related characteristics of the heterojunction and resulted in less agglomeration. In particular, such heterojunction formed by nanofiber and nanosheet can enhance the transport of charges and reduce the recombination probability of photoexcited charge carriers, ultimately further improve the photodegradation efficiency 53 . TEM image (Fig.…”
In this study, graphitic carbon nitride (g-C3N4) and niobium pentoxide nanofibers (Nb2O5 NFs) heterojunction was prepared by means of a direct electrospinning approach combined with calcination process. The characterizations confirmed a well-defined morphology of the g-C3N4/Nb2O5 heterojunction in which Nb2O5 NFs were tightly attached onto g-C3N4 nanosheets. Compared to pure g-C3N4 and Nb2O5 NFs, the as-prepared g-C3N4/Nb2O5 heterojunction exhibited remarkably enhanced photocatalytic activity for degradation of rhodamine B and phenol under visible light irradiation. The enhanced catalytic activity was attributed predominantly to the synergistic effect between g-C3N4 sheets and Nb2O5 NFs, which promoted the transferring of carriers and prohibited their recombination, confirmed by the measurement of transient photocurrent responses and photoluminescence spectra. In addition, the active species trapping experiments indicated that superoxide radical anion (Ā·O2ā) and hole (h+) were the major active species contributing to the photocatalytic process. With its high efficacy and ease of preparation, g-C3N4/Nb2O5 heterojunction has great potentials for applications in treatment of organic pollutants and conversion of solar energy.
“…Figure 9(b) shows linearized kinetic curves, determination coefficients (R 2 , Table 5) of which indicate that reaction kinetics for all samples is adequately described by the Langmuir-Hinshelwood model, being in full agreement with the literature data [58][59][60]. The corresponding apparent rate constants (K, Table 5) confirm the previously obtained results regarding the highest photocatalytic activity of the P25TiO 2 -SnO 2 sample (apparent rate constant of which is 1.75 times higher than that of unmodified TiO 2 P25).…”
The paper presents the results of characterization and study of adsorption-photocatalytic properties of commercial and synthesized-by-hydrothermal method TiO2 and TiO2-SnO2 nanocomposites. Hydrothermal synthesis of TiO2-based nanocomposites was performed in two ways: single-stage and two-stage methods. Characterization was carried out by XRD, X-ray fluorescence method, XPS, EPR, PL, and low-temperature adsorption-desorption of nitrogen, which showed that TiO2-SnO2 nanostructured composites were obtained with tin(IV) oxide content of 10āwt.% and had acidic surface and different porous structures. Besides, modification of a commercial sample with tin(IV) oxide led to a slight decrease in the specific surface area, while modification of a synthesized-by-hydrothermal method TiO2 sample led to an increase. It was found that sorption properties of the obtained nanocomposites and pure TiO2 are better towards anionic dyes. Photocatalytic activity, on the contrary, is higher towards cationic dyes, which is consistent with additional studies on the destruction of these dyes. It was established that in terms of photocatalytic activity, TiO2-SnO2 nanocomposites are more promising than solid solutions, and modification of TiO2 with tin(IV) oxide, in general, leads to improvement of its photocatalytic activity.
“…Trapping experiments of active species were carried out to confirm the active species that contribute to the photocatalytic degradation MB experiments over Ag/TiO 2 /PDA-bamboo. The hydroxyl radical (ā¢OH), hole ( h + ), and superoxide radical anion (ā¢O 2ā ) were captured by corresponding trapping agents of Methanol (MeOH), triethanolamine (TEOA), and p -benzoquinone (BQ) 17 . As shown in Fig.…”
Section: Resultsmentioning
confidence: 99%
“…Photocatalysis, utilizing solar energy over semiconductors, has recently attracted considerable attentions in the fields of materials science, energy, environmental science, and disinfection 7ā12 . Nanosized TiO 2 with high chemical and thermal stability, non-toxicity, large specific surface area and high catalytic performance has been widely used for various applications 13ā17 . And it has been regarded as an effective, economic and environmental way to solve the mildew problem compared with organic anti-mildew agents which are commonly toxic and expensive 18ā20 .…”
Bamboo with the outstanding properties, such as good mechanical strength, fast growth rate and low growth cost, is considered as one of utilitarian structural nature materials. But bamboo is easy to get mildewed resulting in disfiguration and fungi corrosion. In this work, a facile method was developed to improve the mildew-proofing capability of bamboo. Mussel-inspired polydopamine (PDA) with biomimetic adhesion function and highly active functional groups was employed to immobilize highly-dispersed Ag and TiO2 nanoparticles on the surface of bamboo via an in-situ growth method. Integrating the uniform PDA coating, photocatalytic function of TiO2 nanoparticles and bactericidal role of Ag nanoparticles, the mildew-proofing capability of bamboo is enhanced significantly. The results show a non-covalent interaction is more likely to account for the binding mechanism of PDA to bamboo. And the prepared bamboo samples show good photocatalytic performance and have excellent resistance leachability. Meanwhile, the mildew-proofing property of prepared bamboo sample was greatly improved.
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