Quantum Dots Loading Research Articles

Pd quantum dots loading Ti3+,N co-doped TiO2 nanotube arrays with enhanced photocatalytic hydrogen production and the salt ions effects

Pd quantum dots (QDs) loading Ti3+,N co-doped TiO2 nanotube array (NTA) films were prepared by anodic oxidation of Ti foils, followed by calcination at 400 °C and Pd photo-depositions using a PdCl2 solution. The photocatalytic hydrogen production activity of the Pd QDs loading Ti3+,N co-doped TiO2 NTA was tested under UV–vis light irradiation in a methanol aqueous solution and compared with those of Ag and Au loaded Ti3+,N co-doped TiO2 NTAs. The effects of Pd content, salt ions and catalytic reaction temperature on the photocatalytic activities of the Pd QDs loading Ti3+,N co-doped TiO2 NTA catalysts were explored systematically. The photocatalytic reaction mechanism was proposed based on the experimental results. The results show that the hydrogen evolution reaction (HER) rate (17.6 µmol cm−2h−1) over the Pd QDs loading TiO2NTA/Pd10 (10 cycles of Pd photo-depositions) was increased to 16 times higher than that of the unloaded TiO2NTA (1.1 µmol cm−2h−1). Interestingly, adding small amount of alkali salt (0.5 g L−1) in the preparation process of the TiO2 NTAs or in the photocatalytic reaction medium (1 g L−1) can further increase the HER rates distinctly (2.7–3.4 times).

Surface-engineering of decahedron shaped bismuth vanadate for improved photoelectrochemical water oxidation by indium doping coupled with graphitic carbon nitride quantum dots

Surface of a photocatalyst critically determines the efficiency of water oxidation by providing suitable reaction sites and energetics. Manipulating the properties of semiconductor surface for better charge extraction and efficiency forms the basis of present study. We chose monoclinic BiVO4 as a model system, due to its suitable band structure and stability with a theoretical current density approaching 7 mA/cm2 is a promising material for photoelectrochemical water oxidation. An in-situ growth procedure yields, indium doped BiVO4 (BiVO4:In) photoanode with distinctive morphology. This photoanode forms a type II heterojunction (BiVO4:In)-CNQD) with g-C3N4 quantum dots (CNQD) loading to address the shortcomings. A photocurrent density of ~2.42 mA/cm2 with a solar to hydrogen conversion of 2.66% with an average Faradaic yield of 90% is yielded, which is ~4-folds higher than its bare counterpart. (BiVO4:In)-CNQD photoanode shows a significant cathodic shift of 136 mv than bare BiVO4 photoanode. Indium in BiVO4 favors the creation of oxygen vacancies, which improves charge separation and charge carrier density in BiVO4:In photoanode. It is also observed that the BiVO4:In photoanode shows higher surface hydrophilic characteristics, results in more polar surface and water adsorption on the surface, leading to more active water at the reaction site.

Interface modulation of BiVO4 based photoanode with Bi(III)Bi(V)O4 for enhanced solar water splitting

Despite being considered as one of the most promising semiconductor photocatalysts, BiVO4 still suffers the problems of inefficient light harvesting, multiple charge recombination channels and back reactions, restricting its application for solar energy conversion. Here, we demonstrate a unique Bi2O4(400)/BiVO4(040) heterojunction prepared via an oxidation conversion process, which dramatically accelerated the interfacial charge transfer compared to pure BiVO4. Furthermore, with Mo doping, carbon quantum dots (CQDs) loading and Ni-FeOOH co-catalyst deposition, the resulting Bi2O4/Mo-BiVO4/CQDs/Ni-FeOOH photoanode reaches a remarkable photocurrent density of 6.7 mA/cm2 at 1.23 V vs. RHE under AM 1.5G irradiation in the absence of hole scavengers. Our findings demonstrate that proper material interface engineering together with composition tuning provides a viable route to achieve highly efficient solar water splitting.

Uniform-dispersed ZnS quantum dots loading on graphene as a promising anode for potassium-ion batteries

The potassium-ion batteries (PIBs) have become the promising energy storage devices due to their relatively moderate cost and plenteous potassium resources. Whereas, the main drawback of PIBs is unsatisfactory electrochemical performance induced by the larger ionic radius of potassium ion. Herein, we report a well-designed, uniform-dispersed, and morphology-controllable zinc sulfide (ZnS) quantum dots loading on graphene as an anode in the PIBs. The directed uniform dispersion of the in-situ growing ZnS quantum dots (∼2.8 nm in size) on graphene can mitigate the volume effect during the insertion-extraction process and shorten the migration path of potassium ions. As a result, the battery exhibits superior cycling stability (350.4 mAh/g over 200 cycles at 0.1 A/g) and rate performance (98.8 mAh/g at 2.0 A/g). We believe the design of active material with quantum dot-minimized size provides a novel route into PIBs and contributes to eliminating the major electrode failure issues of the system.

CdSe quantum dots modified thiol functionalized g-C3N4: Intimate interfacial charge transfer between 0D/2D nanostructure for visible light H2 evolution

Abstract In this paper, a novel hybrid photocatalyst comprising of CdSe quantum dots (QDs) supported on thiol (-SH) functionalized g-C3N4 sheet (TF-g-C3N4) has been synthesized and studied for hydrogen (H2) evolution. Thiol-functional group has a strong affinity towards the CdSe QDs, which assists the uniform dispersion of 0-dimensional CdSe QDs on TF-g-C3N4 sheets. The hybrid-structure of CdSe-TF-g-C3N4 prepared by different weight % loading of CdSe QDs (6 wt %, 12 wt %, 18 wt % and 24 wt %) on TF-g-C3N4 sheets. Thiol-functional group on the g-C3N4 sheet acts as a hole quencher, which suppresses the photogenerated charge recombination. The enhanced photocatalytic rate of H2 generation was observed for the functionalized TF-g-C3N4 sheet (8.1 times) as compared to non-functionalized g-C3N4 sheet. The hybrid-structure photocatalyst with 18 wt% CdSe QDs on TF-g-C3N4 sheet shows the synergetic increase in photocatalytic H2 evolution compared to its components due to intimate interfacial attachment between CdSe QDs and –SH functional group. At an irradiation wavelength of λ ≥ 420 n m , 18 wt% CdSe-TF-g-C3N4 shows steady H2 evolution at the rate of 31,000 μmolh−1g−1, which is over 103.3 fold the rate of H2 evolution for g-C3N4 sheets and 12.3 times TF-g-C3N4. The developed heterostructure photocatalyst 18 wt% CdSe-TF-g-C3N4 shows an outstanding apparent quantum yield (AQY) efficiency of 13.86% at an irradiation wavelength of 460 nm. Hence, this novel heterostructure, CdSe -TF-g-C3N4 proves itself as one of the capable candidates for visible-light photocatalyst with optimum morphology, and bandgap.

Pt quantum dots decorated nest-like 3D porous ZnO nanostructures for enhanced visible-light degradation of RhB

In this work, a novel Pt/ZnO composite: Pt quantum dots decorated nest-like 3D porous ZnO nanostructures has been prepared via a simple and effective method. The effect of loading Pt quantum dots on photocatalytic properties of ZnO nanostructures is investigated by using SEM, TEM, EDX, XPS, PL, UV–Vis DRS, and BET studies. The results show that nest-like 3D porous ZnO nanostructures can be rapidly synthesized at 80 ℃ for 30 min under microwave heating. Subsequently, the metallic Pt quantum dots are successfully supported and uniformly distributed on the nest-like ZnO nanostructures by photochemical method to form the Pt/ZnO composite. The loading of Pt quantum dots on the nest-like 3D porous ZnO nanostructures intensively increases the visible light absorption resulting in about 4 times higher current response to the visible light, together with the BET surface area enhancement by 75%, than that of the pure ZnO. As a result, Pt/ZnO composite exhibits high catalytic stability and photocatalytic activity towards the degradation of Rhodamine B. In addition, the enhanced photocatalytic activity of Pt/ZnO is attributed to the Pt quantum dots acting as excellent photosensitizer and transporter of photogenerated electrons under visible light, which can retard the recombination of electrons and holes.

Optimal fabrication of 0D/1D Cu2O quantum dots sensitized CdS nanorods heterojunction: Efficient photoredox catalyst for H2 generation under visible light irradiation

Abstract The heterogeneous structure of Cu2O quantum dots (QDs) sensitized CdS nanorods (NRs) was synthesized by an easy and cost-effective technique. The morphology, structure and optical properties of as-prepared photocatalysts are thoroughly investigated by field emission gun scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UVDRS) and photoluminescence (PL) spectroscopic techniques. The different weight percentages (10, 20, and 30) of Cu2O QDs deposited on the CdS NRs structures and their photocatalytic hydrogen (H2) evolution (PCHE) performance are systematically investigated. The Cu2O QDs deposition on CdS NRs shows an increase in the rate of hydrogen (H2) evolution due to the formation of type II heterojunction in between Cu2O QDs and CdS NRs. The 20% loading of Cu2O QDs on CdS exhibits the highest photocatalytic H2 generation than other ratios as well as pure Cu2O QDs and CdS NRs. The photocatalytic rate of H2 evolution of 26060 μmolg-1h-1 was obtained for 20 % Cu2O-CdS, which is18 times more than pure Cu2O QDs and 5.1 times than CdS NRs. Photoelectrochemical (PEC) measurements, electrochemical impedance spectroscopy, and photoluminescence measurements suggest that the Cu2O QDs deposition on CdS NRs reduces interfacial recombination of photogenerated charge carrier owing to the formation of the p-n junction between the components. The apparent quantum yield (AQY) obtained for 20 % Cu2O QDs modified CdS NRs photocatalysts is exceptionally high i.e. 20.67%. This convenient and cost-effective strategy will pave the way for large-scale synthesis of type II heterogeneous photocatalyst for efficient H2 evolution.

A sensitive immunoassay for simultaneous detection of foodborne pathogens using MnO2 nanoflowers-assisted loading and release of quantum dots

In this study, a sensitive immunoassay using immunomagnetic nanobeads (MNBs), manganese dioxide nanoflowers (MnO2 NFs) and quantum dots (QDs) was developed for simultaneous detection of E. coli O157: H7 and Salmonella typhimurium. MnO2 NFs were synthesized, functionalized and incubated with QDs to obtain QDs@MnO2 nanocomposites, followed by modification with antibodies (pAbs) to obtain pAb-QDs@MnO2 nanocomposites (QM NCs). Target bacteria were first conjugated with MNBs and QM NCs to form MNB-bacteria-QM complexes. Then, QDs were quickly released from the complexes using glutathione to reduce MnO2 to Mn2+. Finally, fluorescent intensity at characteristic wavelength was measured by optical detector to determine target bacteria. This immunoassay could simultaneously and quantitatively detect E. coli from 1.5 × 101 to 1.5 × 106 CFU/mL with detection limit of 15 CFU/mL and Salmonella from 4.0 × 101 to 4.0 × 106 CFU/mL with detection limit of 40 CFU/mL in 2 h. The mean recovery for both bacteria in spiked chicken samples was ∼96%.

Ultrathin TiO2-coated SiO2 nanoparticles as light scattering centers for quantum dot-sensitized solar cells

SiO2/TiO2 core/shell nanoparticles (ST-NPs) with an ultrathin and conformal TiO2 shell were fabricated via atomic layer deposition (ALD) technique with a specially-designed rotary reactor. We successfully employed the ST-NPs as light scattering centers in a mesoporous TiO2 photoanode in quantum dot (QD)-sensitized solar cells (QDSSCs). ST-NPs enhanced the light scattering in the TiO2 photoanode without deterioration of QD loading behavior. Consequently, visible light absorbance was improved in the PbS QDs-sensitized TiO2 photoanode, and thus the photocurrent density increased from 14 to 17 mA/cm2. Detailed electron microscopy was utilized to reveal the uniqueness of the ultrathin TiO2 shell in ST-NPs, and in-depth electrochemical impedance spectroscopy divulged the increase in photogenerated carrier lifetime and improved recombination resistance for the QDSSC with ST-NPs.

Controlling Pt co-catalyst loading in a WO3 quantum dot and MoS2 nanosheet composite Z-scheme system for enhanced photocatalytic H2 evolution

A solid-state Z-scheme system, with the synergistic integration of the advantages of various narrow-band semiconductors, is considered to be a potential strategy to develop efficient photocatalysts for operation under visible light illumination. However, the charge separation efficiency of these systems has always been reduced by disordered electron transfer between coupling semiconductors. In this work, we constructed a direct Z-scheme system WO3-MoS2-Pt through the loading of WO3 quantum dots onto MoS2 nanosheets and the selective depositing of a Pt co-catalyst onto MoS2. X-ray diffraction, transmission electron microscopy, atomic electron microscopy and x-ray photoelectron spectroscopy, etc were used to confirm the successful preparation of the targeted photocatalyst. This photocatalytic system showed high visible-light-driven H2 evolution activity (802.2 μmol · h−1 · g−1) and good photostability. Control experiment and mechanism analysis suggested that the remarkable performance can be attributed to the heterojunction formed WO3 and MoS2 and the vectorial electron transfer (WO3 → MoS2 → Pt) achieved by selectively loading the Pt co-catalyst.

A sensitive electrochemiluminescence biosensor based on metal-organic framework and imprinted polymer for squamous cell carcinoma antigen detection

An electropolymerized dopamine molecularly imprinted polymer (MIP) electrochemiluminescence (ECL) biosensor was constructed to detect squamous cell carcinoma antigen (SCCA). Besides having a large surface area, which allows the loading of more ZnSe quantum dots (ZnSeQDs), Fe(III)-MIL-88B-NH2 metal organic framework (MOF) is an efficient co-reaction accelerator that facilitates the transition of S2O82− into SO4−. As a result, the signal probe of Fe(III)-MIL-88B-NH2@ZnSeQDs/Ab has a strong ECL emission, which allowed the development of a three-way signal amplification strategy for ZnSeQDs emission. The electropolymerized dopamine MIP was found to improve the selectivity in the detection of SCCA. Under optimized conditions, the biosensor displayed a wide linear range from 0.0001 to 100 ng mL-1 with a detection limit of 31 fg mL-1. The prepared biosensor showed several advantages, including good specificity, outstanding selectivity and excellent stability. The proposed method can be used for the rapid and sensitive detection of SCCA in human serum and has promise for clinical application.

Flexible Microsensor Made of Boron-Doped Graphene Quantum Dots/ZnO Nanorod for Voltammetric Sensing of Hydroquinone

The micro size and mechanical properties of carbon fiber make it an ideal electrode material, but the low surface area of carbon fiber promotes a poor electrochemical response. The combination of graphene quantum dots and metal oxide may modulate their chemical and electrochemical properties, resulting in synergistic signal amplification effect. In this study, a new robust nano-hybrid microelectrode was designed by modifying carbon fiber with boron-doped graphene quantum dots/ZnO nanorod for the electrocatalytic analysis of hydroquinone (HQ). Remarkably, high specific surface area of vertically-aligned ZnO nanorod promoted loading of high-density boron-doped graphene quantum dots. Electrochemical results showed that these modifications promoted a larger active surface area and electron transfer of the carbon fiber microelectrode, as well as enhancement of the electrocatalytic activity toward HQ. Under optimal conditions, the linear response range of the proposed microelectrode to HQ was 0.1 to 100 μM, and the limit of detection was 0.03 μM. The proposed microelectrodes show good repeatability, reproducibility and electrode stability. Furthermore, the proposed microelectrode was successfully applied to environmental water samples analysis of HQ, providing a new method for the efficient detection of HQ.

Electrophoretic Deposition of Quantum Dots and Characterisation of Composites.

Electrophoretic deposition (EPD) is an emerging technique in nanomaterial-based device fabrication. Here, we report an in-depth study of this approach as a means to deposit colloidal quantum dots (CQDs), in a range of solvents. For the first time, we report the significant improvement of EPD performance via the use of dichloromethane (DCM) for deposition of CQDs, producing a corresponding CQD-TiO2 composite with a near 10-fold increase in quantum dot loading relative to more commonly used solvents such as chloroform or toluene. We propose this effect is due to the higher dielectric constant of the solvent relative to more commonly used and therefore the stronger effect of EPD in this medium, though there remains the possibility that changes in zeta potential may also play an important role. In addition, this solvent choice enables the true universality of QD EPD to be demonstrated, via the sensitization of porous TiO2 electrodes with a range of ligand capped CdSe QDs and a range of group II-VI CQDs including CdS, CdSe/CdS, CdS/CdSe and CdTe/CdSe, and group IV-VI PbS QDs.

Stimuli-responsive photoluminescence soft hybrid microgel particles: synthesis and characterizations

Stimuli-responsive (pH and temperature sensitive) photoluminescence hybrid particles are prepared using oppositely charged cationic microgels of Poly(N-isopropyl polyacrylamide) (PNIPAm) and anionic cadmium sulfide (CdS) quantum dots (QDs). A facile synthetic strategy such as in situ/post incorporation of QDs along with pH tuneable electrostatic interactions is optimized to obtain hybrid microgels with maximum photoluminescence. Transmission electron microscope (TEM), fluorescence spectroscopy and dynamic light scattering (DLS) methods are used for characterizing the synthesized hybrid particles. TEM studies directly confirm the successful loading of QDs onto microgels whereas fluorescence spectroscopy reveals higher photo luminosity of the hybrid microgels prepared via in situ compared to post incorporation method. The pH-dependent photoluminescence supported by temperature-dependent swelling studies using DLS suggest that the hybrid microgels prepared at low pH have greater fluorescence with less thermoresponsivity and these behaviors follow an opposite trend with increasing pH. Further, these results are compared with the hybrid microgels prepared using similar charged anionic microgels and anionic quantum dots under same experimental condition (via in situ) and suggest that maximum photoluminescence can be achieved only through oppositely charged species.

Boosting the Photocatalytic Ability of g-C3N4 for Hydrogen Production by Ti3C2 MXene Quantum Dots.

The big challenging issues in photocatalytic H2 evolution are efficient separation of the photoinduced carriers, the stability of the catalyst, enhancing quantum efficiency, and requiring photoinduced electrons to enrich on photocatalysts' surface. Herein, Ti3C2 MXene quantum dots (QDs) possess the activity of Pt as a co-catalyst in promoting the photocatalytic H2 evolution to form heterostructures with g-C3N4 nanosheets (NSs) (denoted g-C3N4@Ti3C2 QDs). The photocatalytic H2 evolution rate of g-C3N4@Ti3C2 QD composites with an optimized Ti3C2 QD loading amounts (100 mL) is nearly 26, 3 and 10 times higher than pristine g-C3N4 NSs, Pt/g-C3N4, and Ti3C2 MXene sheet/g-C3N4, respectively. The Ti3C2 QDs increase the specific surface area of g-C3N4 and boost the density of the active site. Besides, metallic Ti3C2 QDs possess excellent electronic conductivity, causing the improvement of carrier transfer efficiency.

Enhanced imaging of glycan expressing cancer cells using poly(glycidyl methacrylate)-grafted silica nanospheres labeled with quantum dots

Glycosylation on the cell surface contains abundant biological information, and detecting the glycan on cell surfaces can offer critical insight into biology and diseases. Here, a signal amplification strategy for the sensitive detection of glycan expression on the cell surface was proposed. In this approach, glycans on the cell surface were detected with poly(glycidyl methacrylate)-grafted silica nanosphere labeled with quantum dots (QDs) and biotin through the specific affinity reaction of avidin-biotin on the cancer cells. Glycans on the cell surface were first labeled via selective oxidization of sialyl groups into aldehydes by periodate. Aniline-catalyzed hydrazone ligation with biotin hydrazide was then used for the specific recognition to avidin. The nanoprobe was fabricated with “living” SiO2 nanoparticles with alkyl bromide groups on their surfaces. They were then subsequently grafted with poly(glycidyl methacrylate) (PGMA) brushes via the successive surface-initiated atom transfer radical polymerization. The CdTe QDs and biotin were immobilized through a ring-open reaction with epoxy groups in the PGMA brushes to obtain QDs/biotin-polymer brush-functionalized silica nanosphere (SiO2-PGMA-QDs/biotin). Enhanced sensitivity could be achieved by an increase in CdTe QDs loading per assay event, because of the large number of surface functional epoxy groups offered by the PGMA. As a result, fluorescence signal increased versus the unamplified method. This method successfully demonstrates a simple, specific, and potent method to detect glycans on the cell surface.

Enhanced Photoelectrochemical Performance of WO3 -Based Composite Photoanode Coupled with Carbon Quantum Dots and NiFe Layered Double Hydroxide.

An attractive photoanode material, WO3 , has suffered from its limited visible-light absorption and sluggish surface reaction kinetics, as well as poor stability in neutral electrolytes. Herein, a NiFe/CQD/WO3 composite photoanode was designed and fabricated, with loading of carbon quantum dots (CQDs) and electrodeposition of NiFe layered double hydroxide. The NiFe/CQD/WO3 photoanode obtained a photocurrent density of 1.43 mA cm-2 at 1.23 V vs. reversible hydrogen electrode, which is approximately three times higher than that of bare WO3 . During the test period of 3 h, the stability of WO3 was improved substantially after the loading of cocatalysts. Furthermore, mechanistic insights of the favored band structure and beneficial charge-transfer pathway elucidate the high photoelectrochemical performance of the NiFe/CQD/WO3 composite photoanode.

Photoelectrochemical Formation of Polysulfide at PbS QD-Sensitized Plasmonic Electrodes.

Effective electron-hole separation is a key to enhance photoenergy conversion of semiconductor quantum dot (QD)-sensitized plasmonic solar cells. However, in contrast to intense studies on electron transfer, hole transfer from QDs and consequent chemical reactions with donors in electrolytes remain unclear. Herein, in situ electrochemical surface-enhanced Raman scattering (SERS) measurement on a PbS QD-sensitized TiO2/Au/TiO2 photoelectrode indicated formation of cyclo-octasulfur (α-S8) via tuning the electrochemical potential. A photocurrent density of 100 nA/cm2 was recorded simultaneously even with an extremely low QD loading. Two-dimensional correlation analysis of the SERS revealed subsequent formation of S8- and S42- at -1.1 to -0.1 V (vs Ag/AgCl), S8 from -0.3 V, and S52- and S62- at ≥0.2 V via complex disproportionation reactions. The sensitive detection is attributed to the enhanced electromagnetic field of localized surface plasmon resonance, which provides a better understanding of charge separation processes in QD-sensitized solar cells.

Sn4+ doping combined with hydrogen treatment for CdS/TiO2 photoelectrodes: An efficient strategy to improve quantum dots loading and charge transport for high photoelectrochemical performance

We demonstrate that Sn4+ doping and hydrogen treatment can be used as effective strategies to fundamentally improve the loading of CdS quantum-dots per-unit-area and the charge transport of TiO2 nanorods. By tuning doping concentration, the Sn4+ doped TiO2 nanorods which are prepared by one-pot hydrothermal method enhance light absorption, decrease electron transport resistance, then improve photon-to-charge conversion owing to the generation of doping energy level and mixed-cation composition of SnxTi1-xO2. Moreover, after hydrogen treatment at various temperatures, many oxygen vacancies and hydroxyl groups are formed on the surface of SnxTi1-xO2 nanorods, which have broadened light absorption to visible region and facilitated charge separation and transport, thus improving the photoelectrochemical properties. Remarkably, the surface active center density of TiO2 nanorods increases arising from Sn4+ doping and hydrogen treatment, which is beneficial to sensitize more uniform and dense CdS quantum-dots. Additionally, the Sn4+ doped and hydrogen treated CdS/TiO2 photoelectrodes show the maximum photocurrent density of 7.72 mA cm−2 at 0 V versus Ag/AgCl, which is 15.8 and 2.3 times higher than that of conventional TiO2 and CdS/TiO2 photoelectrodes, respectively, due to the enhanced optical absorption, increased heterojunction areas and superior charge transport properties, demonstrating their promising potential in various solar-energy driven applications.

High selectivity for room temperature detection of ammonia via in-situ Raman spectroscopy based on Pt quantum dots modified WS2 nanosheets

Currently, the determination of room-temperature gas-sensing performance is primarily based on the method of collecting and analyzing the electrical signals generated after gas interacting with sensitive materials. However, we found that there are Raman characteristic peaks associated with gas sensitivity in the in-situ Raman tests, which is considered as a favorable voucher for evaluating gas-sensing performance. Moreover, in-situ Raman spectroscopy is a non-destructive analytical technique for in-depth understanding of the chemical structure, changes in bonds under atmosphere, etc. of materials. In this study, in order to investigate the Raman signals of the sensitive materials under room-temperature ammonia (NH3) atmosphere and evaluate its gas-sensing performance, the nanocomposites of tungsten disulfide (WS2) nanosheets (NSs) decorated by platinum (Pt) quantum dots (QDs) were prepared by in-situ hydrothermal method for in-situ Raman spectroscopy tests under room-temperature NH3 atmosphere. The Raman spectrum results show that there is the characteristic peak at 1328 cm−1, and the peak intensity ratio of the characteristic peak to the strongest Raman peak of WS2 NSs shows an approximately linear with the concentration of NH3, and behave good stability and selectivity to NH3. Furthermore, the effective area percentage of Pt QDs loading on WS2 NSs is approximately linear with the theoretical molar ratio of Pt to WS2, indicating that the theoretical molar ratio and the actual effective area percentage to the peak intensity ratio are consistent. The in-situ Raman technique under atmosphere could provide a direction for evaluating room-temperature gas-sensing performance.