Heterostructure Nanocomposites Research Articles

Nanostructured ZnO‐CQD Hybrid Heterostructure Nanocomposites: Synergistic Engineering for Sustainable Design, Functional Properties, and High‐Performance Applications

Hybrid nanocomposites integrating nanostructured zinc oxide (ZnO) and carbon quantum dots (CQDs) with designed heterostructures possess exceptional optical and electronic properties. These properties hold immense potential for advancements across diverse scientific and technological fields. This review article investigates the synthesis, properties, and applications of ZnO‐CQD heterostructure nanocomposites. Recent breakthroughs in fabrication methods are examined, including hydrothermal, microwave‐assisted, and eco‐friendly techniques. Key preparation methods such as sol‐gel, co‐precipitation, and electrochemical deposition are discussed, emphasizing their role in controlling heterostructure formation. This review analyses the impact of heterostructures on optical and electronic properties, such as fluorescence, photoluminescence, and photocatalytic activity. Synergistic interactions between ZnO and CQDs within heterostructures are highlighted, demonstrating how they lead to substantial performance improvements. Applications of ZnO‐CQD heterostructures span solar cells, LEDs, photodetectors, water purification, antimicrobial treatments, gas sensing, catalysis, biomedical imaging, drug delivery, environmental sensing, and energy storage. Insights are provided into refining synthesis methods, enhancing characterisation techniques, and broadening the application landscape. Challenges like stability are addressed, along with strategies for optimised performance and practical implementation.

Enhanced piezocatalytic degradation of mixed organic dyes using BaTiO3–MoS2 heterostructure nanocomposites: A mechanistic investigation

Piezocatalysis garners significant interest as a potential solution to environmental issues, specifically regarding dye pollutants. Nonetheless, the main obstacle in the piezoelectric efficiency of materials for eliminating organic pollutants from water has been the recombination of charge carriers. Here we report on the fabrication of a piezoelectric nanocomposite of BaTiO3 (BT) Nanoparticles and MoS2 (MS) Nanosheets for the enhanced piezocatalytic degradation of dye pollutants. The sample with 1.0 wt % MoS2 content (BT/MS1) demonstrates greater efficacy compared to both 2.0 wt % MoS2 (BT/MS2) and BaTiO3 (BT) alone in degrading Rhodamine B (Rh B) and Methyl Orange (MO). Specifically, BT/MS1 exhibits 1.84- and 2.8-times enhanced performance for Rh B and MO degradation respectively, in comparison to BT alone. It is demonstrated that the charge transfer system at the interface of BT and MS effectively lowers the recombination of electron-hole (e‒- h+) pairs, generated during piezocatalysis thereby enhancing the degradation. The composite sample was further used for the successful degradation of a mixture of dyes. This study introduces a novel approach to enhance catalysis by hybrid composite in piezoelectric materials.

Ferroelectric heterostructure nanocomposites based on Bi2MoO6 nanosheets and Bi2S3 nanorods for rapid piezocatalysis of organic dyes and antibiotics

Among numerous polluting compounds, the organic dyes and antibiotics are two servious factors causing water pollution. Hence, it is urgent to find a fast and safe way to degrade waste water in a sustainable approach. Here, ferroelectric heterostructure based on 2D Bi2MoO6 nanosheets and Bi2S3 nanorods has been prepared by a two-step solvothermal method for the reduction of organic dyes and antibiotics. Due to the energy band balance between Bi2S3 and Bi2MoO6, the formed type-II heterostructure can populate charge transfer at the junction and effectively inhibit electron-hole recombination. Under ultrasonic stimulation, catalytic active sites of a Bi2MoO6/Bi2S3 heterostructure for pollutant degradation can be generated through rapid charge transfer activation, thus enhancing the catalytic degradation effect of organic dyes and antibiotics. The Bi2MoO6/Bi2S3 heterostructure not only has good degradation effect, but also shows better stability. This work opens up new avenues for designing highly-efficient catalysts, which is of importance for wastewater degradation and energy-saving applications.

Interface engineering of 1D/2D FeVO4/MoS2 hetero-structured nanocomposite with effective interfacial charge transfer: Facile synthesis and antibiotic drug degradation

The rapid accumulation of organic contaminants in wastewater is a considerable environmental concern. We are investigating nanoscale FeVO4 and MoS2 structures for enhanced removal of organic pollutants to overcome this challenge. The FeVO4/MoS2 nanocomposite was synthesized via a hydrothermal technique. This study looks at how the FeVO4/MoS2 nanocomposite could be explored as a good catalyst for the degradation of ciprofloxacin drug through Photo-Fenton process. The synergy between FeVO4 and MoS2 and hydroxyl radicals leads to accelerated degradation. Our findings imply that FeVO4/MoS2 nanocomposites could remove pharmaceutical pollutants from wastewater sources, contributing to water treatment technology.

Novel CuBi2O4-BiOCl/rGO heterostructure nanocomposite as high-performance visible light photocatalyst for the disintegration of persistent antimicrobials in aquatic environment

The article highlights the fabrication of a novel CuBi2O4-BiOCl/rGO heterojunction nanocomposite as a renewable visible light photocatalyst for the quick disintegration of a persistent fluoroquinolone-based antimicrobial drug, i.e., enrofloxacin (ENF) in aquatics. CuBi2O4-BiOCl (CBO-BOC) nanocomposites (NCs) of varying BOC stoichiometric ratios were synthesized, of which CBO-(30%) BOC NC (CB-30) revealed top photocatalytic traits, which was analogously dispersed onto reduced graphene oxide (rGO) nanosheets, to serve as the visible light photon responsive materials. The electron microscopic and spectroscopic techniques were deployed to understand the CB-30/rGO heterostructure's surface topography and structural morphology. The FE-SEM, HR-TEM and XPS analysis confirmed the dispersion of CBO nanospheres onto the BOC nanoflakes and further confirmed the successful imbuement of CB-30 NCs onto the rGO nanosheets. The CB-30/rGO photocatalyst revealed excellent porosity and surface area for the fast dissipation of pharmaceutical pollutants. The impact of various operating parameters, such as solution pH, drug concentration, CBO-BOC stoichiometry, CB-30/rGO dosage, photosensitizers/electron acceptors, light intensity and matrix tolerance limits, were augmented to enhance the photocatalytic efficiency of the proposed new-age photocatalyst. Under optimized conditions, complete drug mineralization was achieved in ≤0.33 h for complete mineralization of 30 ppm of ENF, using 0.075 g of photocatalyst. The time-dependent profiling of photoproducts/intermediates derived from the photocatalytic degradation of ENF was monitored by HR-MS analysis. The acute and chronic toxicity effects of ENF and its organic intermediate were predicted using the ECOSAR model for selected aquatic life forms. The photocatalyst exhibited reusability up to seven cycles, with excellent thermal/chemical stability, for pollutant decontamination from industrial effluents and environmental samples.

Bifunctional ligand Co metal-organic framework derived heterostructured Co-based nanocomposites as oxygen electrocatalysts toward rechargeable zinc-air batteries

Rational construction of efficient and robust bifunctional oxygen electrocatalysts is key but challenging for the widespread application of rechargeable zinc-air batteries (ZABs). Herein, bifunctional ligand Co metal–organic frameworks were first explored to fabricate a hybrid of heterostructured CoOx/Co nanoparticles anchored on a carbon substrate rich in CoNx sites (CoOx/Co@CoNC) via a one-step pyrolysis method. Such a unique heterostructure provides abundant CoNx and CoOx/Co active sites to drive oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), respectively. Besides, their positive synergies facilitate electron transfer and optimize charge/mass transportation. Consequently, the obtained CoOx/Co@CoNC exhibits a superior ORR activity with a higher half-wave potential of 0.88 V than Pt/C (0.83 V vs. RHE), and a comparable OER performance with an overpotential of 346 mV at 10 mA cm−2 to the commercial RuO2. The assembled ZAB using CoOx/Co@CoNC as a cathode catalyst displays a maximum power density of 168.4 mW cm−2, and excellent charge–discharge cyclability over 250 h at 5 mA cm−2. This work highlights the great potential of heterostructures in oxygen electrocatalysis and provides a new pathway for designing efficient bifunctional oxygen catalysts toward rechargeable ZABs.

A Photoelectrochemical Sensor for the Sensitive Detection of Cysteine Based on Cadmium Sulfide/Tungsten Disulfide Nanocomposites.

In this work, a CdS-nanoparticle-decorated WS2 nanosheet heterojunction was successfully prepared and first used to modify ITO electrodes for the construction of a novel photoelectrochemical sensor (CdS/WS2/ITO). The thin-film electrode was fabricated by combining electrophoretic deposition with successive ion layer adsorption and reaction techniques. The results indicated that the synthesized heterojunction nanomaterials displayed excellent photoelectrochemical performance which was much better than that of pristine CdS nanoparticles and 2D WS2 nanosheets. Owing to the formation of the surface heterojunction and the effective interfacial electric field, the enhanced separation of photogenerated electron-hole pairs led to a remarkable improvement in the photoelectrochemical activity of CdS/WS2/ITO. This heterojunction architecture can protect CdS against photocorrosion, resulting in a stable photocurrent. Based on the specific recognition between cysteine and CdS/WS2/ITO, through the specificity of Cd-S bonds, a visible-light-driven photoelectrochemical sensor was fabricated for cysteine detection. The novel photoelectrochemical biosensor exhibited outstanding analytical capabilities in detecting cysteine, with an extremely low detection limit of 5.29 nM and excellent selectivity. Hence, CdS-WS2 heterostructure nanocomposites are promising candidates as novel advanced photosensitive materials in the field of photoelectrochemical biosensing.

Formation of Mn4Si7/Si(111), CrSi2/Si(111), and CoSi2/Si(111) Thin Film and Evaluation of Their Optically Direct and Indirect Band Gap

Now, silicon-based heterostructured nanocomposites are of great interest. Despite the fact that silicon semiconductor films (crystalline, polycrystalline, amorphous) have been systematically studied for a long time, heterostructural films are new materials, the study of which began relatively recently. We will produce and investigate the properties of heterostructured Mn4Si7/Si(111), CrSi2/Si(111), and CoSi2/Si(111) thin films using infrared and ultraviolet spectroscopies. Absorption, transmission, and diffuse reflectance spectra are obtained applying FTIR spectroscopy instruments and a UV spectrophotometer. The band gap energies calculated from the transmission spectra are in the interval 0.32–1.31 eV for films deposited on the silicon substrates and in the interval 0.36–1.25 eV for the glass substrates.

Facile synthesis of NiMn2O4/ZnMn2O4 heterostructure nanocomposite for visible-light-driven degradation of methylene blue dye

Nowadays, waste discharge and contaminants in drinking water have emerged as a significant global problem. Therefore, it is necessary to remove these pollutants from the water and photocatalysis is the best technique for this purpose. The co-precipitation technique was employed to produce NiMn2O4 and ZnMn2O4 and a photocatalyst containing NiMn2O4/ZnMn2O4 heterostructure nanocomposite. Various analytical techniques have been ascribed to examine the physical, morphological and optical features of the fabricated catalysts. XRD diffraction peak patterns were utilized to confirm the presence of cubic NiMn2O4, tetragonal ZnMn2O4 and NiMn2O4/ZnMn2O4 phases in a nanocomposite. In photodegradation tests, the nanocomposite catalyst outperformed the individual catalysts. After 60 minutes of visible light exposure, this nanocomposite catalyst eliminated the methylene blue (MB) dye, attaining substantially higher degradation rates than pure NiMn2O4 (66%) and ZnMn2O4 (77%). The nanocomposite catalyst was highly effective against methylene blue (MB) dye with a degradation efficiency of 92%.

Enhanced charge carriers separation/transportation via S-scheme ZnCeS–ZnWO heterostructure nanocomposite for photodegradation of synthetic dyes under sunlight

Domestic wastage and liquid discharge from industries cause serious water pollution and severely damage the life cycle of living species. Therefore, it is necessary to construct efficient photocatalysts for the removal of toxic pollutants from water. Herein, a novel heterostructure ZnWO–ZnCeS nanocomposite was prepared by the sol-gel route and studied its physical and photocatalytic properties using various analytical techniques. Under sunlight irradiation, the ZnWO–ZnCeS photocatalyst eliminated 99.7, 99.1, 99.0 % rhodamine-B (RhB), methylene blue (MB), and safranin-O (SO) dyes within 70 min with excellent performance higher than individual ZnWO and ZnCeS catalysts. The optimization tests exhibit the catalyst loading = 30 mg, dye content = 25 ppm, solution pH = 8 of ZnWO–ZnCeS against MB dye for practical application. The heterojunction of coupled ZnWO and ZnCeS leads to a synergistic effect that facilitates the charge transport and hampers the recombination of photo-induced charge carriers thereby leading to boosted photocatalytic performance. Furthermore, based on the scavenging test, the hydroxyl and superoxide radicals were the reactive species during the photodegradation reaction. The designed photodegradation reaction mechanism has proposed the formation of an S-scheme in ZnWO–ZnCeS that led to the accumulation of electrons at ZnCeS and holes at ZnWO, favoring the formation of reactive species for dye degradation. Moreover, this work provides a novel direction to synthesize S-scheme heterostructure photocatalysts for application in wastewater treatment.

Recent Advances in Efficient Photocatalytic Degradation Approaches for Azo Dyes

In recent decades, the textile industry has contributed to continuous pollution in the environment. Synthetic dyes which are commonly found in waste water are azo, sulfur, anthraquinone, triphenylmethyl, indigoid, and phthalocyanine derivatives. These pollutants block the light penetration in water bodies and prevent photosynthesis activity, thereby affecting aquatic life. As an environmental crisis, several technologies have been explored to control pollution. Among all the techniques, the photocatalysis process is considered as a green, simple, and economical process. To improve the photocatalytic activity, researchers worldwide have investigated various photocatalysts such as metal oxides, metal ferrites, and heterostructured nanocomposites. The major goal of this review article is to propose a high-performing, cost-effective hybrid photocatalyst reported to date for prospective azo dye pollutant remediation. This review article also aimed to highlight the challenges and uncertainties associated with dye degradation in the photocatalytic process.

High discharge energy density in rationally designed graphene oxide@zinc oxide/polymer blend-polyetherimide heterostructured bilayer nanocomposites

The advancement of new dielectric materials exhibiting greater discharge energy density is crucial for current power systems and electronic devices. In this work, various weight percentages of graphene oxide@zinc oxide (GO@ZO) nanofillers were incorporated inside a polymer blend of poly(vinylidene fluoride-hexafluoropropylene)/polyetherimide (P(VDF-HFP)/PEI; shortened as BP) and used as a high dielectric top layer. In contrast, linear-type PEI (L) was used as a bottom insulation layer to achieve a high breakdown strength (Eb) in bilayer nanocomposites. As a result, the 2BP-L composite demonstrated a high discharged energy density of 12.63 J/cm3 at an electric field of 527 MV/m with only 2 wt% GO@ZO nanofillers addition in the top layer. Such a high discharge energy density with minimal nanofiller loading is attributed to the utilization of novel surface-decorated GO@ZO nanofillers and new bilayer-heterostructured linear/ferroelectric-linear polymer. In comparison to its counterparts (i.e., PEI, P(VDF-HFP) and 0BP-L), the 2BP-L nanocomposite showed ∼426.3 %, 92.5 %, and 9.8 % enhancement in discharge energy density, respectively. The discharge rate and stability analysis revealed a significantly higher power density of 0.55 MW/cm3, indicating its high potential to be used as a pulsed power system. Finite element simulation revealed that the effective internal electric field distribution and higher dielectric displacement in 2BP-L resulted in such enhancement over its counterparts. This study presents a new model to maximize the energy storage capability of flexible energy storage devices and advances knowledge of the polarization mechanisms and breakdown of bilayer nanocomposite dielectric materials.

Near-Infrared-II-Activatable Self-Assembled Manganese Porphyrin-Gold Heterostructures for Photoacoustic Imaging-Guided Sonodynamic-Augmented Photothermal/Photodynamic Therapy.

Porphyrins and their derivatives are widely used as photosensitizers and sonosensitizers in tumor treatment. Nevertheless, their poor water solubility and low chemical stability reduce their singlet oxygen (1O2) yield and, consequently, their photodynamic therapy (PDT) and sonodynamic therapy (SDT) efficiency. Although strategies for porphyrin molecule assembly have been developed to augment 1O2 generation, there is scope for further improving PDT and SDT efficiencies. Herein, we synthesized ordered manganese porphyrin (SM) nanoparticles with well-defined self-assembled metalloporphyrin networks that enabled efficient energy transfer for enhanced photocatalytic and sonocatalytic activity in 1O2 production. Subsequently, Au nanoparticles were grown in situ on the SM surface by anchoring the terminal alkynyl of porphyrin to form plasmonic SMA heterostructures, which showed the excellent near-infrared-II (NIR-II) region absorption and photothermal properties, and facilitated electron-hole pair separation and transfer. With the modification of hyaluronic acid (HA), SMAH heterostructure nanocomposites exhibited good water solubility and were actively targeted to cancer cells. Under NIR-II light and ultrasound (US) irradiation, the SMAH generates hyperthermia, and a large amount of 1O2, inducing cancer cell damage. Both in vitro and in vivo studies confirmed that the SMAH nanocomposites effectively suppressed tumor growth by decreasing GSH levels in SDT-augmented PDT/PTT. Moreover, by utilizing the strong absorption in the NIR-II window, SMAH nanocomposites can achieve NIR-II photoacoustic imaging-guided combined cancer treatment. This work provides a paradigm for enhancing the 1O2 yield of metalloporphyrins to improve the synergistic therapeutic effect of SDT/PDT/PTT.

Optimizing Gas Sensing Properties of Fe-Loaded Indium Zinc Oxide Nanocomposite for Efficient Detection of Ammonia Gas

The current study delineates the role of gas sensing properties of Fe-IZO (Iron loaded Indium Zinc oxide) a mixed metal oxide nanocomposite. The heterostructured Fe-IZO nanocomposite (NC) was synthesized via the facile co-precipitation method. The Fe-IZO NC was characterized by various experimental techniques and the results attained allowed us to suggest the mechanism for considering the connection between morphological variations and gas-sensing characteristics of Fe-IZO NC. One of the cutting-edge circumstances now-a-days is the prime use of gas sensors for environmental applications. The NC has a good selectivity for NH3 gas that has shown good stability up to 80 d. The response time (ℸres) is 64 s, recovery time (ℸrec) is 72 s for 50 ppm (parts per million) and obtained a highest response of 87% at room temperature. The Fe-IZO NC heterostructure with efficient charge transfer can enable the subsequent reaction mechanism with NH3 gas and the adsorbed oxygen ions leading to an increased response. Consequently, the results attained in this work has shown that the synthesized heterostructured NC sensor is suitable for room temperature NH3 sensing with high performance.

Synthesis of heterostructured nanocomposites as supercapacitor electrodes and investigation of their electrochemical properties

Synthesis of heterostructured nanocomposites as supercapacitor electrodes and investigation of their electrochemical properties

Design of rich defects carbon coated MnFe2O4/LaMnO3/LaFeO3 heterostructure nanocomposites for broadband electromagnetic wave absorption

The precise construction of abundant heterointerfaces and defects in manganese ferrite for efficient electromagnetic wave (EMW) absorption is highly appealing, yet remains a grand challenge. Herein, we report a class of carbon-coated MnFe2O4/LaMnO3/LaFeO3 heterostructure nanocomposites with foam-like porous structures for enhancing EMW absorption. The optimized sample (the molar ratio of Mn:Fe:La is 1:2:1) delivers extraordinary absorption performance of the minimum reflection loss reaches −68.25 dB at 4.24 GHz, along with the maximum effective absorption (RL ≤ -10 dB) bandwidth is 12.26 GHz (3.11–15.37 GHz) at a thickness of 3.9 mm. EMW absorption mechanism reveals that the multiple polarizations induced by adjustable heterointerfaces and abundant defects in spinel/perovskite nanocomposites enhance its dielectric loss capacity, resulting in impressive EMW absorption performance. Moreover, the amorphous carbon shell further optimizes impedance matching. This study not only provides a good reference for future preparation of microwave absorbing materials with rich heterogeneous interfaces and defects but also broadens the application of such kinds of carbon-coated spinel/perovskite nanocomposites.

Facile synthesis of green engineered CuO/Cu2O-C nano heterostructures with the controlled Cu2O content for the photodegradation of crystal violet

Copper oxide/cuprous oxide and carbon heterostructured nanocomposites (CuO/Cu2O-C NCs) were fabricated using an agro-biomass wheatgrass extract (WGE), presenting an innovative, eco-friendly, and facile green synthetic approach. The CuO/Cu2O-C nanocomposites engineered using WGE were extensively characterized using UV–Vis, IR, XRD, DLS, XPS, SEM, TEM, BET, and TGA characterization techniques. The synthesized CuO/Cu2O-C NCs were crystalline with a monoclinic phase and an average crystallite size of 32 nm, as confirmed by XRD. Tauc plots were utilized to calculate the band gap energies (2.05 and 1.53 eV). The synthetic procedure is optimized, and the effect of plant extract in the controlled synthesis of Cu2O content in the CuO/Cu2O-C NCs was investigated. These green CuO/Cu2O-C NCs were tested for photocatalytic activity. A detailed kinetic study was conducted to degrade pathological effluent crystal violet (CV). The nanocomposite with a higher concentration of Cu2O is potentially a superior photocatalyst and demonstrated an excellent synergistic action, removing around 80 % of the crystal violet stain in visible light. Apart from photodegradation, these CuO/Cu2O-C NCs were good antioxidants and displayed good antibacterial activity against the gram-positive and gram-negative bacterial strains. The key highlight of this work is the low-cost disruptive engineering strategy for synthesizing frugal nanomaterials for multifaceted applications.

Efficient photodegradation of paraquat herbicide over TiO2-WO3 heterojunction embedded in diatomite matrix and process optimization.

Photodegradation of paraquat herbicide was assessed over several TiO2-WO3 heterojunctions embedded in the diatomite matrix. The characterization results indicated that WO3 embedding in the TiO2 decorated-diatomite matrix could not only enhance the adsorption capacity, visible-light response, and distribution of semiconductor species but also lessen the recombination rate and band gap energy. These characteristics were more noticeable as 5 wt.% of WO3 was embedded. Despite better optical properties of immobilized TiO2-WO3 nanocomposites, overloading WO3 generally alleviates the synergetic effect of tungsten due to surface coverage of diatomite matrix and, subsequently, the significant attenuation of textural properties, more formation of agglomerations and defects as trapping centers in the oxidation sites of heterostructures, and also, less likely of forming TiO2-WO3 heterojunction. In accordance with characterization results, the highest UV-photodegradation of paraquat was attained over heterostructured nanocomposite containing 5 wt.% WO3 (T25-W5/Di). The effects of significant operating parameters were also investigated, modeled, and optimized using response surface methodology (RSM)-central composite design (CCD). Under optimized operation conditions, the experimental removal efficiency of paraquat reached 97.1 and 80% using UV and simulated solar light, respectively. Moreover, the reusability results confirm the sustained activity of the T25-W5/Di nanocomposite.

Constructing novel inorganic-organic α-Fe2O3/SNW-1 Z-scheme heterojunction for Methylene Blue photodegradation

A novel organic/inorganic heterostructured photocatalyst binary nanocomposite was typically prepared by the solvothermal method. The overwhelming superiority of this composite has been confirmed by spectroscopic and characterization methods, where the addition of α-Fe2O3 reduced the agglomeration of the Schiff-based covalent organic framework SNW-1 and significantly increased the specific surface area. The effects of operating parameters such as catalyst dosage, initial solution concentration, and pH on photocatalytic degradation of methylene blue (MB) dye were carefully investigated. Among them, a UV irradiation time of 80 min, a powder dose of 0.6 g/L, and pH=2 were the best choice. Under these favorable conditions, the α-Fe2O3/SNW-1 system exhibited excellent photocatalytic performance, and the degradation rate of MB reached more than 95%. In addition, the photocatalytic degradation efficiency of the pollutants acid orange 7 (AO7), rhodamine-B (RhB), and acid red (ArB) comfortably reached 92%, 92%, and 91%, respectively. After five cycles of testing, the prepared photocatalyst showed good stability and reusability. Through energy band calculation, free radical quenching experiment, and electron paramagnetic resonance (ESR) study, it was discovered that the main active substances were ·O2- and ·OH, and the photogenerated holes and electrons also participated in the photocatalytic reaction. The Z-scheme charge transfer mechanism of α-Fe2O3/SNW-1 was proposed. Photoelectric chemical tests further demonstrated the extraordinary photocatalytic activity, low internal resistance, and high carrier separation capability of the binary nanocomposites. This study presents the potential application of high-performance photocatalysts for the removal of organic dyes in water purification.

PtS-decorated WS2 microflakes based sensors for selective ammonia detection at room temperature

In this paper, platinum sulfide decorated WS2 microflakes (PtS/WS2) heterostructure nanocomposites were prepared by an in-situ chemical reduction process. The chemiresistive-type gas sensor based on the synthesized PtS/WS2 heterostructure nanocomposites exhibited a significantly improved sensing properties compared to that of the pure WS2 microflakes at different concentration of NH3 from 1 ppm to 10 ppm at room temperature. As the concentrations of PtS nanoparticles decorated on the surface of WS2 microflakes increased, the response of the PtS/WS2 heterostructure sensor to ammonia firstly increased when the concentration of PtS increased up to 1 wt%, whereas above 1%, the response decreased instead. Moreover, it was found that the response speeds of the PtS-decorated WS2 were significantly improved compared to that pure WS2. The sensors also exhibited excellent selectivity to formaldehyde, toluene, acetone, methanol and ethanol at room temperature. The sensing mechanisms were studied by using the in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The enhanced sensing properties could be explained by “electronic sensitization” effect induced by the PtS/WS2 heterostructure, being confirmed by density functional theory (DFT) calculations.