As-synthesized Heterostructures Research Articles

In situ fabrication of oxygen deficient Bi2MoO6/InVO4/CeVO4 dual S-scheme ternary heterostructure for robust photocatalytic H2 and H2O2 production

Mild in situ synthesis of ternary dual S-scheme heterostructure photocatalyst with high redox ability of photo-excitons is a pragmatic approach for achieving rapid activation of tenacious atmospheric molecules. In the present study, a series of Bi2MoO6/InVO4/CeVO4 ternary heterostructures were constructed by in situ deposition of Bi2MoO6 nanoplates over one pot synthesized InVO4/CeVO4 using a facile oil bath heating method. The as-synthesized heterostructure materials were comprehensively characterized to understand their structural, optical, electrochemical and morphological properties. The ternary heterostructure displayed a distinct morphology consisting of Bi2MoO6 nanoplates, CeVO4 nanosheets and InVO4 nanorods. The significant intergrowth among the constituent phases through the in situ coupling strategy also led to the construction of tight interfacial microscopic junctions. The important attributes of the ternary heterostructures included intense photon absorption in whole UV-visible region, drastic decrease in photogenerated charge recombination and higher excited state lifetime. Both InVO4 and CeVO4 individually as well as the ternary heterostructure contained surface oxygen vacancies that further promoted efficient charge separation and activation of atmospheric molecules. The optimized ternary photocatalyst displayed 2314 μmol/g/h H2 generation and 1700 μM/g/h H2O2 production which are 12-86 and 11-27 times higher than the pristine semiconductors, respectively. Detailed band position assessment and radical entrapment analysis suggested the occurrence of a dual S-scheme charge transfer mechanism that rationally accounted for the remarkable enhancement in the photocatalytic performance.

CeO2 quantum dots decorated g-C3N4 nanosheets: A potential scaffold for fluorescence sensing of heavy metals and visible-light driven photocatalyst

Herein, we report the synthesis of g-C3N4/CeO2 heterostructure using a facile co-precipitation method. The as-synthesized g-C3N4/CeO2 heterostructure was examined by several techniques in order to understand the morphology, thermal, structural, optical and compositional properties. A strong interfacial contact was observed between g-C3N4 nanosheets and CeO2 quantum dots (QDs) as CeO2 QDs were deposited on g-C3N4 nanosheets with slight agglomeration. The as-synthesized heterostructure was successfully applied as a probe for the fluorescence sensing of heavy transition metals (Cu(II), Hg(II) and Ag(I)) and a visible light active photocatalyst for the decomposition of tetracycline (TC) in an aqueous phase. The g-C3N4/CeO2 heterostructure exhibited remarkable selectivity towards the sensing of Cu(II), Hg(II) and Ag(I) heavy metal ions because of strong binding affinity of these metal ions towards nitrogen and oxygen containing functional moieties present in g-C3N4/CeO2 heterostructure. Furthermore, a good linearity was observed between the relative FL intensity and concentration of Cu(II), Hg(II) and Ag(I) ions with detection limit estimated to be 26.2 µM, 17.5 µM and 14.9 µM, respectively. The high selectivity for these ions was due to their strong binding affinity towards nitrogen and oxygen containing functional groups in g-C3N4/CeO2 heterostructure. Moreover, the removal efficiency of 77.95% was acquired for degradation of tetracycline in 160 min using g-C3N4/CeO2 heterostructure under optimized conditions. The photocatalytic results of the heterostructure could be accredited to the reduction in the recombination of excited carriers across the interface of the heterojunction. Therefore, the present work provides an effective strategy for the preparation of fluorescent photocatalytic materials that can be utilized for the FL detection of harmful heavy metal ions as well as degradation of pollutants in an aqueous phase.

Facile synthesis of ZnO/CuO/Eu heterostructure photocatalyst for the degradation of industrial effluent

Zinc oxide-based ternary heterostructure ZnO/CuO/Eu(1%, 3%, and 5% of Eu) nanoparticles were effectively produced by employing Vigna unguiculata(cowpea)waste skin extract as fuel in a simple one-pot combustion process. The as-synthesized heterostructure was analyzed by X-ray diffraction studies, ultraviolet-visible spectroscopy, Fourier Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscopy, and High-Resolution Transmission Electron Microscopy techniques. Besides, the photocatalytic degradation efficiency of the as-obtained ternary nanocomposite was evaluated under UV light for the degradation of model organic pollutants including methylene blue (MB), Rhodamine-B (RB), and an effluent sample collected from the textile industrial waste. During this study, the effect of a variety of parameters on the photodegradation activity of the photocatalysts has been thoroughly evaluated, such as light source, catalyst dose, irradiation period, dye concentration, solution pH, etc. Under UV irradiation(100 mins), the ternary ZnO/CuO/Eu photocatalyst demonstrated excellent degradation activity of ∼99 and ∼93% for MB and RB, respectively, while for the industrial effluent, a decent degradation activity of 42% has been recorded. Further experiments have revealed a pH and concentration-dependent photocatalytic behavior of the heterostructure photocatalyst. Therefore, the results suggest that the heterostructure photocatalyst can be potentially applied for wastewater treatment and other environmental applications.

Development of Bi2WO6 and Bi2O3 - ZnO heterostructure for enhanced photocatalytic mineralization of Bisphenol A.

Present study proposed the synthesis of mixed p-type and n-type nanocomposite heterostructures by co-precipitation method. The as-synthesized heterostructures were characterized through different characterization techniques. The as-synthesized Bi2WO6 and Bi2O3-ZnO heterostructures were tested as photocatalysts during the photodegradation of Bisphenol A (BPA). The Bi2O3-ZnO heterostructure nanocomposite was found to be a more effective photocatalyst than Bi2WO6. The effect of operating parameters including catalytic dose (0.02-0.15 gL-1), initial BPA concentration (5-20 mgL-1), temperature change (5-20 °C) and solution pH changes (4, 5, 7, and 8) were evaluated with Bi2O3-ZnO under UV-light irradiation by selecting a 300 W Xe lamp. More than 90% BPA was degraded with 0.15 gL-1 Bi2O3-ZnO, keeping 1.0 mM H2O2concentration fixed in 250 mL of reaction suspension. The HPLC and GC-MS were used to detect the reaction intermediates and final products. A plausible degradation pathway was proposed on the basis of the identification of reaction intermediates. Repeatability test analysis confirmed that the as-synthesized catalyst showed superb catalytic performance on its removal trend. The kinetics of degradation of BPA were well fitted by the power laws model. With the order of reaction being 0.6, 0.9, 1.2, and 1.3 for different operating parameters, i.e., catalyst dose, initial pH, temperature, and initial BPA concentration.

Self-Powered Photodetector Based on FTO/n-TiO2/p-CuMnO2 Transparent Thin Films

A self-powered photodetector with the FTO/n-TiO2/p-CuMnO2 configuration, representing the novelty of the work, was successfully achieved for the first time and presumes two steps: deposition of the n-type semiconductor (TiO2) by the doctor blade method and of the p-type semiconductor (CuMnO2) by the spin coating technique, respectively. Investigation techniques of the structural and morphological characteristics of the as-synthesized heterostructures, such as XRD, UV-VIS analysis, and SEM/EDX and AFM morphologies, were used. The I-t measurements of the photodetector showed that the responsivity in the self-powered mode was 2.84 × 107 A W−1 cm2 and in the 1 V bias mode it was 1.82 × 106 A W−1 cm2. Additionally, a self-powered current of 14.2 nA was generated under UV illumination with an intensity of 0.1 mW/cm2. Furthermore, under illumination conditions, the response time (tres) and the recovery time (trec) of the sensor exhibited a good response; thus, tres = 7.30 s and trec = 0.4 s for the self-powered mode, and in the 1 V bias mode, these were tres = 15.16 s and trec = 2.18 s. The above results show that the transparent heterojunction device of n-TiO2/p-CuMnO2 exhibited a self-powered ultraviolet photodetector with high sensitivity.

Recent Advances on Tuning the Interlayer Coupling and Properties in van der Waals Heterostructures

2D van der Waals (vdW) heterostructures are receiving increasing research attention due to the theoretically amazing properties and unprecedented application potential. However, the as-synthesized heterostructures are generally underperforming due to the weak interlayer coupling, which inspires the researchers to find ways to modulate the interlayer coupling and properties, realizing the tailored performance for actual applications. There have been a lot of publications regarding the controllable regulation of the structures and properties of 2D vdW heterostructures in the past few years, while a review work summarizing the current advances is not yet available, though it is significant. This paper conducts a state-of-the-art review regarding the current research progress of performance modulation of vdW heterostructures by different techniques. First, the general synthesis methods of vdW heterostructures are summarized. Then, different performance modulation techniques, that is, mechanical-based, external fields-assisted, and particle beam irradiation-based methods, are discussed and compared in detail. Some of the newly proposed concepts are described. Thereafter, applications of vdW heterostructures with tailored properties are reviewed for the application prospects of the topic around this area. Moreover, the future research challenges and prospects are discussed, aiming at triggering more research interest and device applications around this topic.

Superior photoelectrochemical performance of Fe2O3/g-C3N4 heterostructure synthesized by chemical precipitation method

TheFe2O3/g-C3N4 was fabricated via. chemical precipitation employing graphitic carbon nitride (GCN) and iron-nitrate precursors.XRDandFTIRspectroscopy were used to confirm phase identification and impurity study of the as-synthesized heterostructure.SEMwas used to explore the morphology of the as-synthesized heterostructure. EDS confirmed the elemental composition of the Fe2O3/g-C3N4 heterostructure. The UV–visible spectra were used to assess the optical properties, which revealed a band structure in the visible region that is favourable for photoelectrochemical performance. Using a simulated visible light source, the photoelectrochemical performance of the Fe2O3/g-C3N4 heterostructure was examined, revealing a good photocurrent density of the as-synthesized heterostructure.

Fabrication of a UV Photodetector Based on n-TiO2/p-CuMnO2 Heterostructures

The heterojunction based on n-TiO2 nanolayer/p-CuMnO2 thin film was achieved using an efficient two-step synthesis process for the fabrication of a UV photodetector. The first step consisted of obtaining the TiO2 nanolayer, which was grown on titan foil by thermal oxidation (Ti-TiO2). The second step consisted of CuMnO2 thin film deposition onto the surface of Ti-TiO2 using the Doctor Blade method. Techniques such as X-ray diffraction, UV-VIS analysis, SEM, and AFM morphologies were used for the investigation of the structural and morphological characteristics of the as-synthesized heterostructures. The Mott–Schottky analysis was performed in order to prove the n-TiO2/p-CuMnO2 junction. The I-V measurements of the n-TiO2 nanolayer/p-CuMnO2 thin film heterostructure confirm its diode characteristics under dark state, UV and visible illumination conditions. The obtained heterojunction, which is based on two types of semiconductors with different energy band structures, improves the separating results of charges, which is very important for high-performance UV photodetectors.

A cost-effective approach to synthesize NiFe2O4/MXene heterostructures for enhanced photodegradation performance and anti-bacterial activity

A cost-effective ultrasonication approach was employed to synthesize NiFe2O4/MXene heterostructures. The as-synthesized heterostructures demonstrated outstanding photodegradation performance and anti-bacterial activity as compared to individual NiFe2O4 (NiFe) or MXene. The NiFe nanoparticles (NPs) helped in effectively preventing the re-stacking of MXene flakes and in increasing the surface area of the heterostructure. The obtained sheet-sheet linkage provided an admirable opportunity for excellent wastewater treatment and antibacterial activity. The photocatalytic degradation of organic pollutants by the introduced photocatalyst NiFe/MXene heterostructures has been observed to be about 4 and 6.72 times boosted compared to MXene and NiFe, respectively. Furthermore, the heterostructure materials demonstrated outstanding anti-bacterial activity against gram negative E-coli bacteria, while the mechanism of methylene blue dye degradation by NiFe/MXene was clarified through kinetic studies of the degradation process. We hope this work will be considered a significant scientific contribution for young researchers dealing with water desalination.

Facile Fabrication of a ZnO/Eu2O3/NiO-Based Ternary Heterostructure Nanophotocatalyst and Its Application for the Degradation of Methylene Blue.

The ZnO-based ternary heterostructure ZnO/Eu2O3/NiO nanoparticles are synthesized using waste curd as fuel by a simple one-pot combustion method. The as-synthesized heterostructure is characterized by using various spectroscopic and microscopic techniques including X-ray diffraction, UV–vis, FTIR, SEM, and TEM analyses. The photocatalytic activity of the ternary nanocomposite was tested for the photodegradation of methylene blue (MB) under solar light irradiation. The results have revealed that the ternary ZnO/Eu2O3/NiO photocatalyst exhibits excellent performance toward the photocatalytic degradation of the studied dye. Optimization studies revealed that the synthesized heterostructure exhibited a pH-dependent photocatalytic activity, and better results are obtained for specific concentrations of dye and catalysts. Among the different light sources employed during the study, the catalyst was found to possess the best degradation efficiency in visible light.

Construction of carbon nanotube mediated Fe doped graphitic carbon nitride and Ag3VO4 based Z-scheme heterojunction for H2O2 assisted 2,4 dimethyl phenol photodegradation

Rational design strategy with a facile synthetic approach of environmental-friendly photocatalysts is a unique challenge in photocatalytic technology. The precedent work reports the successful synthesis of a Z-scheme Fe doped graphitic carbon nitride coupled Ag3VO4 compounded with carbon nanotubes (FeCN/AV/CNT) photocatalyst through facile precipitation-deposition technique. Characterization analysis including FESEM, XRD, FTIR, XPS and EDS was conducted to clarify the morphology and structure engineering properties of as-synthesized heterostructures (FeCN/AV/CNT). The efficient photocatalytic removal of 2,4 dimethyl phenol was attributed to multi electron transference route comprising of incorporation of Fe dopant in graphitic carbon nitride (g-C3N4), proceeded by coupling with Ag3VO4 (AV) simultaneously under solar light illumination. FeCN/AV/CNT photocatalyst was converted into a heterogeneous system with the addition of H2O2. The augmentation in catalytic activity was corroborated by photo-Fenton Fe3+ ions and H2O2 to generate more hydroxyl radicals. The positive synergistic effect between Fe-CN/AV/CNT Z-scheme approaches promoted enhancement in photodegradation performance by achieving maximum separation and rapid migration of photogenerated charge carriers, prolonged absorption in visible spectrum with augmented light absorption ability. The rate constant for FeCN/AV/CNT activated H2O2 is about 1.37 and 1.63 times high compared to FeCN/AV/CNT and FeCN/AV and exhibited outstanding catalytic efficiency and stability for five consecutive catalytic cycles. The plausible mechanism of FeCN/AV/CNT H2O2 based Z scheme system was also explored.

Synthesis of Pd nanoparticles modified Bi2MoO6 nanoplates by microwave-assisted deposition with their enhanced visible-light-driven photocatalyst

Heterostructure Pd/Bi2MoO6nanocomposites as visible-light-driven photocatalyst for rhodamine B (RhB) degradation with different weight of Pd have been successfully synthesized by sonochemical-assisted deposition method. The phase, morphologies and atomic oxidation state of as-synthesized heterostructure Pd/Bi2MoO6 nanocomposites with different weight of Pd samples were characterized by several agnatical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), respectively. The XRD pattern of pure Bi2MoO6 samples shown a pure phase orthorhombic Bi2MoO6 structure. After loading Pd, it found the new diffraction peak which can be indexed to cubic Pd structure, indicating that the formation of heterostructure Pd/Bi2MoO6 nanocomposites. SEM and TEM images of heterostructure Pd/Bi2MoO6 nanocomposites show a good disperse randomly of spherical Pd nanoparticles with particle size range of 8−12 nm were covered on the surface of Bi2MoO6 nanoplates. Photocatalytic activities of the pure Bi2MoO6 sample and heterostructure Pd/Bi2MoO6 nanocomposites have been observed that heterostructure 5% Pd/Bi2MoO6 nanocomposites showed the highest visible-driven photocatalytic activity of 97.76 % for RhB degradation within 150 min while the pure Bi2MoO6 sample is 36.93 % for RhB degradation at same condition.

Pt nanoparticles on Ti3C2Tx-based MXenes as efficient catalysts for the selective hydrogenation of nitroaromatic compounds to amines.

The development of Pt nanocatalysts for the selective hydrogenation of nitroaromatic compounds to the corresponding amines is of great significance to solve the drawbacks associated with a low reserve of Pt. Herein, we develop a protocol for the preparation of a Pt/titanium carbide-based MXene heterostructure for the selective reduction of nitroaromatic compounds. In the heterostructure, well-defined and nano-sized metallic Pt crystallites are uniformly decorated on Ti3C2Tx nanosheets using a mild reducing agent of ammonia borane without additional stabilizing agents. The selective hydrogenation of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN) was employed as a model reaction to investigate the catalytic performance of the as-synthesized heterostructure, denoted as Pt/Ti3C2Tx-D-AB. Notably, this catalyst can catalyze the complete conversion of p-CNB to p-CAN with 99.5% selectivity, superior to that of Pt/Ti3C2Tx-D-SB synthesized with sodium borohydride. The high performance of the present catalytic system can be ascribed to the well-dispersed Pt nanoparticles, the abundant surface electron-efficient Pt(0), and the synergistic catalysis between Pt/Ti3C2Tx-D-AB and water. This catalyst also shows generality toward the selective hydrogenation of a series of nitroaromatic compounds to the corresponding amines with high efficiency. The present study provides a strategy to synthesize efficient catalysts for catalytic applications.

Investigation of electron beam irradiation on In2S3-MxInySz (M = Bi or La) Z-scheme heterojunctions for efficient and stable degradation of water pollutants

Novel Z-scheme In2S3-MxInySz (M = Bi or La) heterojunction composites were fabricated through a hydrothermal method. An electron beam irradiation technology has been served for artificially creating interface defects on the composites to further enhance photocatalytic activity. SEM and TEM results showed that In2S3-MxInySz composites presented tubular structures composed of randomly assembled ultrathin nanosheets with the incorporation of Bi and La. XRD, FT-IR and XPS results proved that the as-synthesized heterostructure composites were mainly InBiS3 and InLa3S6. The In2S3-MxInySz composites presented distinct optical absorption property in visible lights region and exhibited highly enhanced photocatalytic efficiency for the removal of azo dyes and Cr(VI). Specifically, ISB-60 irradiated by electron beam displayed the best removal efficiency for the water pollutants. PL, DRS and EIS measurements showed that electron beam irradiation could reduce the recombination rate of photoexcited electron-hole pair, resulting in great separation rate of charge carriers. The ESR results confirmed the existence of superoxide radical (•O2−), hole (h+) and hydroxyl radical (•OH) in the photocatalysis process. The •O2− and h+ species possessed a significant oxidizing effect towards the photodegradation of azo dyes and the photoreduction of Cr(VI). The possible transformation pathway for the removal of water pollutants by In2S3-MxInySz (M = Bi or La) composites was proposed by means of GC-MS.

Graphdiyne-engineered heterostructures for efficient overall water-splitting

Efficient overall water splitting (OWS) into hydrogen and oxygen needs an electrocatalyst that can effectively catalyze hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the same electrolyte. Here a new electrocatalyst of graphdiyne-coated nickel oxide heterostructures is synthesized. It can effectively facilitate the charge transfer, increase the electrocatalytically active surface area, maximize the number of electrocatalytically active sites, and protect the catalyst from corrosion during the stability test. Benefiting from these advantages, the electrocatalyst shows superior HER and OER catalytic activities than commercial Pt/C and RuO2, respectively. When being used as both cathode and anode in a two-electrode alkaline electrolyzer, the graphdiyne-based heterostructure shows an excellent OWS performance superior to that of the Pt/C||RuO2 couple. In combination with the theoretical calculations, our results reveal that the as-synthesized heterostructure can significantly improve the charge transfer kinetics and the hydrogen/oxygen-containing species adsorption abilities, therefore maximizing the overall water splitting activities.

Efficient Charge Transfer in Heterostructures of CdS/NaTaO3 with Improved Visible-Light-Driven Photocatalytic Activity.

Photocatalyst NaTaO3 with a cube-shaped morphology and an average particle size of 100 nm was synthesized using an effortless hydrothermal method. The composite heterostructures of CdS/NaTaO3 with variable concentrations of CdS were fabricated after the surface functionalization of bare NaTaO3 using 3-mercaptopropionic acid. As-synthesized photocatalysts were characterized using powder X-ray diffraction analysis, Raman spectroscopy, field-emission scanning and transmission electron microscopies with energy-dispersive X-ray spectroscopy furnished with elemental mapping, multipoint Brunauer–Emmett–Teller (BET), and UV–vis diffuse reflectance spectroscopy. Average lifetime (τavg) of photoexcitons in heterostructures was studied using photoluminescence (PL) empowered with the time-correlated single-photon counting technique. The diminishing PL peak intensity and reduced average lifetime (τavg) of photoexcitons in heterostructures indicate the inhibition of photoexciton recombination along with efficient photoexciton exchange between heterostructures. As-synthesized heterostructures demonstrate enhanced visible-light harvesting and appreciably increased the photocatalytic performance toward the degradation of dye rhodamine B. This work highlights the importance of heterostructures with new archetypes which may provide a lead to develop highly capable and reusable photocatalysts to organic dye degradation.

One-pot facile synthesis of the ZnO/ZnSe heterostructures for efficient photocatalytic degradation of azo dye

Environmental remediation using sunlight is one of the most promising and cost-effective approaches to mitigate environmental hazards significantly related to the industrial development. In the present work, we report the synthesis of ZnO/ZnSe heterostructure via one-pot hydrothermal approach for the photocatalytic degradation of diazo dye i.e. Congo red. XRD analysis verified the crystal structure, phase purity and successful synthesis of the ZnO/ZnSe heterostructure photocatalysts. Moreover, the morphology and elemental composition of the photocatalysts were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron dispersive X-ray spectroscopy (EDX), respectively. The alignment of energy levels for the synthesized heterostructured photocatalysts was also drawn while using UV-visible diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). Finally, the as-synthesized heterostructures were employed as efficient photocatalysts for the degradation of Congo red under the illumination of UV-visible light. Our results indicated that ZnO/ZnSe heterostructure photocatalysts with maximum ZnSe content can efficiently degrade the dye up to 91% which might be attributed to the effective charge separation as extended solar absorption due to narrow bandgap of ZnSe.

Hybrid of AgInZnS and MoS2 as efficient visible-light driven photocatalyst for hydrogen production

We present a simple two-step hydrothermal method to prepare AgInZnS/MoS2 nanocomposite. The morphology and compositional characteristics of the sample were investigated by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The as-synthesized heterostructures exhibited superior photocatalytic activity for hydrogen evolution under visible-light irradiation and the optimum loading amount of MoS2 is at 0.5 wt%. In an attempt to explain this phenomenon, a possible mechanism was also proposed. The enhanced photocatalytic activities toward water splitting arise from the boosted active sites for hydrogen generation and the enhanced charge transfer. This work may contribute to the design and construction of highly efficient visible-light responsive photocatalyst for sustainable energy harvesting and conversion.

Fabrication of flexible nanogenerator with enhanced performance based on p-CuO/n-ZnO heterostructure

A p-CuO/n-ZnO heterostructure was synthesized on an indium tin oxide coated flexible substrate (polyethylene terephthalate) by a simple and low-cost hydrothermal method. Scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction were used to characterize the as-synthesized heterostructure. The results indicated that flower-like CuO nanostructure conformably formed on the ZnO nanorods. Furthermore, a nanogenerator based on the p-CuO/n-ZnO heterostructure was fabricated for harvesting energy from environment, and the output performance of the device was investigated. A larger output current of ~100 nA was obtained in comparison with ZnO based nanogenerator, which could be ascribed to the formation of p–n heterojunctions in the CuO/ZnO composites, reducing the screening effect of excessive electrons. This strategy may provide a highly promising platform for realizing a high-performance flexible piezoelectric energy harvester by new composite piezoelectric material.

Micropored Sn-SnO2/carbon heterostructure nanofibers and their highly sensitive and selective C2H5OH gas sensing performance

Sn-SnO2/carbon heterostructure nanofibers were synthesized by electrospinning and following heat treatment, and their C2H5OH sensing properties were studied. The hetero-nanofibers composed of amorphous carbon and homogeneously distributed Sn-SnO2 particles were characterized by SEM, TEM, EDS, XRD, XPS, FT-IR, Raman and nitrogen adsorption–desorption experiment. A gas sensor was fabricated from the as-synthesized heterostructures of Sn-SnO2/carbon nanofibers and used to test the sensing performance to C2H5OH. The Sn-SnO2/carbon nanofibers showed improved sensing properties compared to pure SnO2 nanofibers. It exhibits a 2-time enhancement in ethanol response compared to the SnO2 nanofibers counterparts at its optimum operating temperature, good linear dependence of response on C2H5OH concentration in the range of 10–100ppm, excellent recovery property and selectivity to C2H5OH. The excellent performance in C2H5OH sensing of Sn-SnO2/carbon nanofibers arises from (i) high specific surface and pore structure provided by one-dimensional carbon nanofibers, (ii) the unique sensing mechanism based on the hybrid Sn-SnO2/carbon nanostructures.