Activity For Methylene Blue Degradation Research Articles

Fabrication of Zn and Ti-loaded Carbon-silica Composite Derived from Gelatin Template for the Photodegradation of Methylene Blue

Carbon-silica nanocomposites (CSNs) from gelatin as a carbon source and natural template and TEOS as a silica source have been successfully synthesized and impregnated into ZnO and TiO2 photocatalysts. The structural, morphological, and textural properties and photocatalytic activity for methylene blue degradation of TiO2/CSNs and ZnO/CSNs were investigated. XRD data revealed that TiO2/CSNs and ZnO/CSNs had different structural characteristics with similar crystallinity. FTIR spectra demonstrated the presence of Zn–O and Ti–OC bonds, respectively, at about 500-450 cm-1 and 1500 cm-1. The morphological surface exhibited stacked tubular shapes of TiO2/CSNs and ZnO/CSNs with the primary elements of Ti, Zn, Si, C, and O. The nitrogen adsorption-desorption curves revealed both micropores and mesopores of TiO2/CSNs and ZnO/CSNs where the surface area reduced due to the blocking pore after impregnation. Moreover, ZnO/CSNs verified a higher degradation percentage against methylene blue than that of TiO2/CSNs. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Green synthesis of Ag/AgCl nanocomposites derived from Muntingia calabura L. leaves extract: antioxidant properties and catalytic activity in methylene blue degradation

ABSTRACT Ag/AgCl nanocomposites were synthesised using Muntingia calabura L. leaves extract for the first time and were used as antioxidants and catalysts in the degradation of methylene blue (MB). This study aimed to achieve the optimal conditions for synthesising Ag/AgCl nanocomposites using Muntingia calabura L. leaves extract and to examine their antioxidant and photocatalytic activities. Ag/AgCl nanocomposites were confirmed using UV-Vis spectroscopy, Fourier transform-infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Zeta Potential analysis. Optimising various factors revealed that the optimum synthesis of Ag/AgCl nanocomposites involved mixing 3 mL of 2.5 mm AgNO3 with 7.5 mL of the extract and stirring continuously at 60°C for 100 min. The formed Ag/AgCl nanocomposites displayed mainly spherical shapes with some irregular forms, maintaining an average size of 69.04 nm and remaining stable for 6 months. In vitro studies on antioxidant activity using DPPH indicated that the Ag/AgCl nanocomposites exhibited outstanding free radical scavenging activity, with an IC50 of 62.76 mg/L. In addition, Ag/AgCl nanocomposites showed a strong photodegradation potential for MB, with a degradation percentage of up to 82.12% in 210 min. Hence, the results offer a promising approach for the environmentally friendly synthesis of Ag/AgCl nanocomposites using Muntingia calabura L. leaves extract, with significant applications in antioxidants and photocatalysts.

Investigation of methylene blue dye degradation using green synthesized mesoporous silver-titanium

In this study, we synthesized mesoporous silver-titanium (Ag/TiO2) through green synthesis approach using mangosteen pericarp extract, which subsequently can act as both adsorbent and photocatalyst materials. Additionally, we investigated and compared the degradation of methylene blue (MB) using mesoporous Ag/TiO2 under dark conditions, visible light irradiation, and both dark-light conditions to analyze the adsorption-photocatalysis activity. The achieved mesoporous structure in this study offers distinct advantages as an adsorbent. Moreover, the addition of silver (Ag) to titanium dioxide (TiO2) shows promise in enhancing photocatalytic activity in MB degradation, which enhances photocatalytic activity in the visible light region due to its localized surface plasmon resonance (LSPR), which excites more electrons, resulting in increased MB degradation. The highest degradation percentage of 97.08 % was obtained using a dark-light degradation mechanism, demonstrating that the synthesized mesoporous Ag/TiO2 has potential as an effective integrated adsorbent-photocatalyst material for MB dye degradation.

The Photocatalytic Activity of TiO2 Nanotube Doped Zn for Methylene Blue Degradation

TiO2 nanotube (TiO2-NT) is one of the promising materials for photocatalytic water remediation. TiO2-NT doped Zn (Zn/TiO2-NT) is synthesized from P25 Degussa via one step hydrothermal method. From XRD and UV-DRS analysis, it showed that Zn as a doping material led to decrease band gap energy and decrease the crystallite size. The best results obtained was Zn/TiO2-NT with a crystallite size of 7.14 nm, and band gap energy value of 3.18 eV. Photocatalytic activity of Zn/TiO2-NT was also tested for photocatalytic activity of textile dye (methylene blue) degradation. During the photocatalytic activity for methylene blue degradation, the Zn/TiO2-NT shows higher activity compared to non-doped sample. The non-doped sample shows degradation activity of 87.72%, meanwhile the Zn/TiO2-NT shows degradation activity of 95.88%.

Sonochemical Assisted Synthesis of Cr-PTC Metal Organic Framework, ZnO, and Fe3O4 Composite and Their Photocatalytic Activity in Methylene Blue Degradation

Methylene blue pollutants can be treated by photocatalytic methods using metal oxide-based semiconductor materials and metal organic framework (MOF). These two materials are often coupled into a composite to improve their physicochemical properties and catalytic activity. This research focuses on the synthesis of composites based on Cr-PTC MOF, ZnO, and Fe3O4 by the sonochemical method. The obtained composites were characterized and tested for catalytic activity in methylene blue pollutant degradation in an aqueous system under acidic conditions (pH = 5). Our investigation shows that the Cr-PTC@Fe3O4 composite possesses the lowest band gap energy of 1.86 eV and achieves the highest photocatalytic activity in methylene blue degradation at solution pH = 5, with a percent degradation of 84.36%. The sonochemical incorporation of Fe3O4 and Cr-PTC MOF is able to fabricate materials in a short time with better photocatalytic activity in degrading methylene blue than the single materials. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Designing Robust CdS Nanostructures for Superior Photostability and Enhanced Photocatalytic Degradation of Organic Pollutants

AbstractTill date it is a great challenge to synthesize CdS photocatalyst with a high stability. In this study, a stable CdS photocatalyst was successfully synthesized by a simple, cost‐effective hydrothermal route via cadmium acetate and thiourea as Cd and S precursors, respectively. The effect of different processing times (8 h and 24 h) and molar ratios on the photocatalytic activity and stability were mainly investigated. The samples were characterized in detail by XRD, FT‐IR, XPS, UV‐vis DRS, Photolummiscence spectroscopy and Surface photovoltage. The photocatalytic activity of the as‐obtained nanostructures was examined for methylene blue (MB) dye degradation under visible light irradiation (λ≥420 nm). After 70 min of irradiation, nearly 82 % of MB was degraded by CdS nanostructures, display an improved photocatalytic activity for MB degradation with an apparent rate constant (k) of 0.019 min−1. Additionally, CdS nanostructures sustained a good photostability after five consecutive cycles. The higher photocatalytic activity of CdS nanostructure is attributed to an efficient separation of photogenerated electron‐hole pairs stimulated by its optimal molar ratio, optimal temperature and surface morphology. Our synthesized stable nanostructures have potential for dye contaminated waste‐water treatment.

Synthesis of SnO2/SrTiO3 composite and photocatalytic activity for methylene blue degradation under sunlight

In this study, the SnO2/SrTiO3 composite has been fabricated by, firstly preparing SnO2 and SrTiO3 through, followed by coupling SnO2 and SrTiO3 by the hydrothermal method at 180 oC for 24 hours. The obtained materials were characterized by X-Ray diffraction (XRD), Fourier transformation infrared spectra (FT-IR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM). The photocatalytic activity of composite was assessed by degradation of methylene blue in water under sunlight. The composite exhibits a good photocatalytic activity compared to individual components (SnO2 and SrTiO3). An enhancement in photocatalytic activity of the composite with the presence of SnO2 has been observed. 1,4-benzoquinone (BQ) và tert-butyl alcohol (TBA) were used as quenchers for trapping photogenerated superoxide radical anions (•O2-) and hydroxyl radicals (•OH), respectively. In the presence of the quenchers, the photocatalytic activity of the composite has decreased significantly.

2D/2D heterojunction of MgAlTi-LDH/g-C3N4 with oxygen vacancy engineering for enhanced photocatalytic activities under natural sunlight

Semiconductor photocatalysis is an ideal method for wastewater treatment. However, the rapid recombination of photogenerated electron-hole pairs limits the improvement of photocatalytic efficiency. Constructing heterostructures by different energy band-matched semiconductors and surface defect engineering are considered as effective strategies to inhibit the recombination of photogenerated electron-hole pairs. Herein, a novel MgAlTi-LDH/g-C3N4 heterojunction was fabricated by in-situ growth of oxygen vacancy rich MgAlTi-LDH on ultrathin g-C3N4 nanosheets first time for the degradation of methylene blue (MB) under natural sunlight. The optical absorption properties, crystalline phase, microstructure, and morphological analysis of the fabricated materials are subsequently characterized by XRD, FT-IR, UV–vis DRS, TEM, BET and XPS. Owing to Ti-doping, oxygen vacancy rich MgAlTi-LDH exhibited superior photocatalytic activity for MB degradation, which was 5.5 times of that of MgAl-LDH. Furthermore, MgAlTi-LDH/g-C3N4 heterostructures showed a higher photocatalytic activity under visible light irradiation, which was 5.9, 4.9, and 3.2 times of that of MgAl-LDH, MgAlTi-LDH and g-C3N4, respectively. Upon natural sunlight irradiation, MgAlTi-LDH/g-C3N4 can degrade 95 % of MB after 130 min of irradiation. The improvement of photocatalytic activity of MgAlTi-LDH/g-C3N4 was attributed to the synergistic effect of MgAlTi-LDH and g-C3N4, surface oxygen vacancies, and heterostructure interface. This work promotes a new strategy to synthesize high-efficiency photocatalysts for the removal of organic pollutants from wastewater by constructing heterojunctions with surface defects.

Environmental-related applications of ZnO nanopowders: Photocatalytic activity and photoluminescence response to ethanol

Zinc oxide (ZnO) and copper-doped zinc oxide (ZnO:Cu) nanopowders were synthesized via solvothermal methods using methanol and hexamethylenetetramine (HMTA). Undoped ZnO nanopowders underwent calcination in O2-rich and H2-rich atmospheres at 600 °C. Samples were studied by scanning electron microscopy, Brunauer–Emmett–Teller (BET) surface area analysis, X-ray diffraction (XRD), and Raman, photoluminescence (PL) and UV–vis absorbance spectroscopies. The doping and calcinations led to a reduction of the optical bandgap of the nanopowders, while their structure remained hexagonal wurtzite with some changes in lattice parameters and average nanoparticle sizes. The Cu2+ doping led to a BET surface area and violet PL component increase. Samples were also examined for environmental related applications, namely as photocatalyzers for dye degradation and as ethanol optical sensors. For photocatalytic activity in methylene blue degradation under UV, H2-rich calcined powders excelled, with a rate constant of −0.076 min−1, surpassing −0.057 min−1 (ZnO:Cu), −0.056 min−1 (O2-rich calcination), and −0.041 min−1 (as-grown ZnO). We propose that this improvement can be attributed to the formation of ZnO/Zn interfaces stemming from the reduction of surface interstitial zinc by H2 during calcination, in addition to the observed reduction of the ZnO bandgap. The doped nanopowders PL also showed excellent response when exposed to ethanol vapor.

Hydrazine-Assisted Synthesis, Structures, Photoelectricity, and Photocatalysis of Ternary Mercury-Tellurostannate Hybrids with Transition-Metal Complexes.

Tellurostannates are traditionally prepared by multistep reactions using the tellurides SnTe, SnTe2, K4SnTe4, or A6SnTe6 (A = K, Rb, or Cs) as precursors, which are usually prepared by the molten reaction of alkali metals Sn and Te under harsh synthetic conditions. Differently, ternary Hg-tellurostannate hybrids [Mn(en)3]HgSnTe3(Te2) (1) (en = ethylenediamine), [Mn(dien)2]HgSnTe3(Te2) (2), and [Fe(dien)2]HgSnTe3(Te2) (3) (dien = diethylenetriamine) were synthesized by one-pot reactions using Sn and Te powders as starting materials in the presence of hydrazine under mild solvothermal conditions. In 1, HgTe3 and SnTe4 units are joined via Te-sharing to form a 1-D polymeric chain [HgSnTe3(Te2)]n2n-, while the [HgSnTe3(Te2)]n2n- chains in 2 and 3 are composed of HgTe4 and SnTe4 units. The common feature of the [HgSnTe3(Te2)2-]n chains in 1-3 is that they are constructed by both the telluride anion Te2- and the polytelluride anion Te22-. 1-3 exhibited strong photocurrent responses with current densities of 5.26, 3.38, and 3.94 μA cm-2, respectively. They showed effective photocatalytic activities for methylene blue degradation with degradation ratios in the range of 85.3-94.6% after light irradiation for 80 min. Investigation of the photocatalytic mechanism showed that •O2- radicals and h+ holes were the main active substances in the photodegradation.

Silver-and-Sulphur-Codoped Fe3O4/TiO2 as a Magnetically Separable Photocatalyst for Methylene Blue Degradation under Visible Light

This research aimed to investigate how the addition of silver and sulphur dopants modified the TiO2 photocatalyst to enhance its responsiveness to visible light and improve its photocatalytic activity for methylene blue degradation. In addition, Fe3O4 was also added as a core to add magnetic properties to the photocatalyst material. The Fe3O4/TiO2-Ag/S materials were prepared using FeCl3.6H2O and FeSO4.7H2O as the magnetite precursors, titanium tetraisopropoxide (TTIP) as the TiO2 precursor, while AgNO3 and CH4N2S were used as the sources for silver and sulphur dopants, respectively. The synthesized materials were next characterized using FT-IR, XRD, UV-Vis spectrophotometer, SEM-EDX, TEM, and VSM. The activity of the photocatalyst was then assessed through methylene blue degradation in a closed reactor involving various contained Ag:S ratios and reusability examination. The evaluation of photocatalytic degradation results was performed using UV-Vis spectrophotometry. Afterwards, the research findings indicate that the Fe3O4/TiO2-Ag/S was successfully synthesized and exhibited magnetic properties with a saturation magnetization value of 5.33 emu/g. The highest photocatalytic activity (98.21%) was observed in Fe3O4/TiO2-Ag/S (1:1) with a band gap energy value of 2.64 eV under visible light exposure at pH 10, 120 min, 10 mg mass of the photocatalyst, and methylene blue concentration of 5 mgL-1. Furthermore, the Fe3O4/TiO2-Ag/S photocatalyst was known to perform good stability through four reuse cycles.
 
 Keywords: Dopants, Fe3O4/TiO2-Ag/S, methylene blue, photocatalytic degradation

Synthesis and characterization of mixed oxides derived from lanthanum orthoferrite perovskite: exploring morphological, spectroscopic, and photocatalytic properties

We synthesized pure and doped gadolinium, samarium, and chromium LaFeO3 denoted as LFO, LFCO, LGFCO, and LSFCO, respectively, employing a straightforward, cost-effective, and environmentally friendly solid-state method. The resulting samples were characterized through powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), and UV–Visible absorption measurements. The PXRD findings affirmed that the phase structures corresponding to LFO, LFCO, LGFCO, and LSFCO manifested at an identical calcination temperature of 1200 °C, adopting orthorhombic systems. The calculated crystallite size for each sample, employing Debye-Scherrer’s equation, ranged from 25 to 37 nm, with LGFCO and LSFCO exhibiting an augmented crystallite size. This enhancement can be attributed to the integration of dopants into the LaFeO3 lattice, facilitating crystallite growth. SEM images portrayed microstructure composed of fine particle sizes and pseudo-spherical morphology, and the stoichiometry of La, Fe, and O in LFO was confirmed by energy dispersive spectroscopy (EDS). Reduction in the band gap was ascribed to the doping effect, with LGFCO exhibiting the lowest band gap value. Notably, this ceramic material demonstrated the highest photocatalytic activity for methylene blue degradation under sunlight radiation, surpassing the performance of the other examined samples.

Facile synthesis of silver chloride-polyaniline nanocomposites and its photocatalytic activity for the degradation of methylene blue

Herein, we report a green and an effective strategy for the synthesis of polyaniline-silver chloride (AgCl@PANI) nanocomposites by using facile in-situ chemical oxidative polymerization method in the presence of as-synthesized silver nanoparticles (Ag NPs) for the study of their photocatalytic activity towards the photodegradation of methylene blue (MB) under UV irradiation. The contents of Ag NPs varied from 2% to 6% during polymerization reaction to get AgCl@PANI nanocomposites. These synthesized polymer nanocomposites were characterized for their structural and optical properties, thermal stability, dc conductivity and photocatalytic activity by FT-IR spectroscopy, XRD, UV–Vis spectroscopy, TGA, SEM, standard four probe method and the photodegradation activity of MB, respectively. XRD analysis confirm the successful formation of AgCl@PANI nanocomposites without the presence of additional phases. TGA shows that AgCl@PANI nanocomposites have excellent thermal stability due to the barrier effect of AgCl moieties bounded with in the polymer chain and the strong physiochemical interactions between PANI and AgCl as inferred from FT-IR and UV–vis analysis. Under UV irradiation, the AgCl@PANI nanocomposite, with 4 wt% of Ag NPs (AgCl@PANI-4%), demonstrated excellent photocatalytic activity for MB degradation with the photodegradation percentage of ∼ 99 % in 20 min. The experimental findings illustrate that the superior photocatalytic activity of AgCl@PANI nanocomposites is owing to incorporation of AgCl moieties in the polymer structure, less needed energy for the formation of electron-hole pairs in the quinoid ring of PANI in the UV-region, enhanced light absorption owing to smaller grain size morphology, high surface area of the nanocomposite and high electrical conductivity (128 mS.cm−2). These results suggest the potential of these synthesized conjugated polymer-based nanocomposites as a photocatalyst for cost-effective and efficient wastewater treatment for the industrial applications.

Full utilization of Cu single atoms on carbon nitride nanofibers for enhanced Fenton-like degradation of methylene blue

The utilization efficiency of single atoms is limited by the active sites being buried in support. To maximize atom utilization, Cu single atoms are anchored on the external surface of g-C3N4 nanofibers (CNNFs), which are fabricated by partial thermal decomposition and subsequent self-assembly in H2O. The abundant N and O-containing functional groups of CNNFs are vital for the loading of Cu. Benefited from the full utilization of Cu sites, CNNF-Cu exhibits excellent Fenton-like catalytic activity for Methylene Blue degradation. The reaction kinetic constant is more than 10 times higher than that of the traditional single-atom catalyst with Cu sites evenly distributed throughout the entire support. CNNF-Cu maintains most of its catalytic activity after five cycle tests, suggesting good stability. This work provides a convenient method to maximize the utilization of single metal atoms for catalytic applications.

Vanadium promoted ZnO films: effects on optical and photocatalytic properties

ABSTRACT The effect of electrodeposition temperature, vanadium doping, and oxidation state of vanadium on the photocatalytic activity of ZnO thin films over ITO substrates were investigated. NH4VO3 aqueous solution was used as precursor to dope ZnO thin film samples with V5+ by dip coating method and oxalic acid was used as reducing agent to synthesize V+4 doped samples. UV-Vis spectroscopy was used to determine the direct and indirect band gap values of thin film samples. Methylene blue (MB) degradation assays were used to evaluate the photocatalytic activity. XPS analysis was used to determine the analyse oxidation state of vanadium over the samples. Photocatalytic activity studies revealed that ZnO samples electrodeposited at 70°C have higher band gap and MB degradation activity under artificial solar irradiation. The presence of vanadium also enhances the photocatalytic activity of ZnO and samples doped with V+4 have higher photocatalytic activity than the samples doped with V+5 sites.

SrTiO3/g-C3N4 mesostructured heterojunctions for photocatalytic evaluation using methylene blue

SrTiO3/g-C3N4 mesostructured heterojunctions were synthesized using hydrothermal method with different weight percentages of SrTiO3 (ST) in carbon nitride (CN). The samples are named as CN-ST05, CN-ST10, CN-ST15, CN-ST20, and CN-ST25 based on 5, 10, 15, 20 and 25 wt% of ST respectively in CN. The surface area of the heterojunctions ranged between 33.7 to 63.4 m2/gm. The optical, structural, and elemental properties of the heterojunctions were evaluated. Finally, the photocatalytic tests confirmed that CN-ST15 showed 97% degradation of methylene blue (MB) after 4 h of visible light irradiation, (the bare CN and ST showed 70% and 34% degradation respectively). The photocatalytic activity for methylene blue degradation followed the trend: CN-ST15 > CN-ST10 ≈ CN-ST20 > CN-ST25 > CN-ST05 > CN > ST.

Improvement of Photocatalytic Degradation of Titanium Dioxide Nanomaterials by Non-metal Doping

Semiconductor photocatalysis is a process that benefits from sunlight to start chemical reactions. In order to take advantage photocatalytic properties of semiconductors and to achieve better performance structural adjustment is needed. In this study, varying amounts of nitrogen were used to modify TiO2 nanostructures using the sol-gel method. The crystalline structure of the synthesized TiO2 nanostructures was studied using the X-ray diffraction (XRD) technique. X-ray photoelectron spectroscopy (XPS) was conducted to analyse the elemental composition of nanomaterials. XPS analyze confirms that nitrogen is introduced into the lattice of TiO2. The photocatalytic degradation of methylene blue (MB) under UV irradiation was employed to assess the photocatalytic performance of the samples. To evaluate degradation, the absorption of MB over time was measured using a UV-Vis spectrophotometer. As a result, the doping process has been found to improve the photocatalytic performance of TiO2, and 0.2% N doped TiO2 nanostructures demonstrated superior photocatalytic activity for photocatalytic degradation of MB.

Photocatalytic Degradation of Methylene Blue Dye Using Cuprous Oxide/ Graphene Nanocomposite

Aims: The aim of this study is to evaluate the photocatalytic degradation of methylene blue dye on cuprous oxide/graphene nanocomposite. Background: Cuprous oxide (Cu2O) nanoparticles are among the metal oxides that demonstrated photocatalytic activity. However, the stability of Cu2O nanoparticles due to the fast recombination rate of electron/hole pairs remains a significant challenge in their photocatalytic applications. This in turn, leads to mismatching of the effective bandgap separation, tending to reduce the photocatalytic activity of the desired organic waste (MB). To overcome these limitations, graphene has been added to make nanocomposites with cuprous oxides. Objective: In this study, Cu2O/graphene nanocomposite was synthesized and evaluated for its photocatalytic performance of Methylene Blue (MB) dye degradation. Method: Cu2O/graphene nanocomposites were synthesized from graphite powder and copper nitrate using facile sol-gel method. Batch experiments have been conducted to assess the applications of the nanocomposites for MB degradation. Parameters such as contact time, catalyst dosage, and pH of the solution were optimized for maximum MB degradation. The prepared nanocomposites were characterized by using UV-Vis, FTIR, XRD, and SEM. The photocatalytic performance of Cu2O/graphene nanocomposites was compared against Cu2O nanoparticles for cationic MB dye degradation. Results: Cu2O/graphene nanocomposite exhibits higher photocatalytic activity for MB degradation (with a degradation efficiency of 94%) than pure Cu2O nanoparticle (67%). This has been accomplished after 180 min of irradiation under visible light. The kinetics of MB degradation by Cu2O/graphene composites can be demonstrated by the second-order kinetic model. The synthesized nanocomposite can be used for more than three cycles of phtocatalytic MB degradation. Conclusion: This work indicated new insights into Cu2O/graphene nanocomposite as highperformance in photocatalysis to degrade MB, playing a great role in environmental protection in relation to MB dye.

Highly efficient recyclable copper (I) chloride complex catalysts having photo-Fenton activity for methylene blue degradation by sunlight

Highly efficient recyclable copper (I) chloride complex catalysts having photo-Fenton activity for methylene blue degradation by sunlight

In-situ growth of g-C3N4 nanosheets on Nb2O5 nanofibers for enhanced performance in photocatalysis and lithium-sulfur battery

A Nb2O5/g-C3N4 composite with a controllable loading amount of g-C3N4 nanosheets is successfully prepared by a combination of electrospinning and the double crucible gas-solid reaction method. During the heat treatment process, the precursor molecules of melamine gas are in-situ polymerized on the surface of Nb2O5 nanofibers to form g-C3N4 nanosheets. The Nb2O5 nanofibers ultralong one-dimensional nanostructure can effectively avoid the aggregations of g-C3N4 and form tight heterojunction interfaces. The optimized Nb2O5/g-C3N4 composite material improved the photocatalytic activity for methylene blue degradation, with a rate constant twice that of Nb2O5 nanofibers and 3.8 times that of pure g-C3N4. Using the combination of DFT theoretical calculations and capture experiments, the transfer mechanism of the Nb2O5/g-C3N4 type-II heterojunction is confirmed. It was found that the d orbital of Nb and the p orbital of N were the main active site of the photocatalytic reaction. Meanwhile, the lithium-sulfur (Li-S) battery assembled with NOCN-8 as the host material exhibited a high initial discharge capacity of 900 mAh g−1 at 0.5 C, and its capacity decay rate was less than 0.1% after 500 cycles. It shows that NOCN-8 can effectively adsorb polysulfide and catalyze the conversion reaction of polysulfide. This work provides a novel route for the synthesis of the Nb2O5/g-C3N4 composite, and has great potential in the development of environmental remediation and energy applications.