Photoluminescence Spectral Analysis Research Articles

Effect of Zinc concentration in CdS thin films deposited in complexing agent by chemical bath deposition: structural, optical, morphological and topographical studies

ZnCdS thin films were prepared by varying the concentration of Zinc (Zn) in the presence of complexing agent, tri-ethanol amine (TEA) and deposited on a glass substrate by chemical bath deposition (CBD) method. The influence of Zn on structural, optical and morphological properties of ZnCdS thin films was studied. From the x-ray diffraction pattern (XRD), the hexagonal structure of ZnCdS thin films was confirmed with an average size of the crystallite (30–36 nm). The optical properties of ZnCdS thin film were investigated using UV–visible absorption and photoluminescence spectral analysis (UV-Vis and PL). The optical studies of thin films indicated that the band gap increased from 1.85 eV to 2.81 eV with increasing the concentration of Zn. Transmission spectra showed a blue shift with increasing the concentration of Zn. The microstructure and morphology of ZnCdS thin films were studied by scanning electron microscope (SEM). The average (Ra) and RMS roughness was calculated by atomic force microscope (AFM). From the results, the nano ZnCdS thin films prepared using various concentrations of Zn could be useful for optoelectronic and device applications.

Synergetic effect of g-C3N4/ZnO binary nanocomposites heterojunction on improving charge carrier separation through 2D/1D nanostructures for effective photocatalytic activity under the sunlight irradiation

The heterojunction between the two different semiconductors shown to increase the photocatalytic activity due to their ability in improving the photo-generated electron-hole pairs separation. Hence designing and synthesizing such heterojunctions employing different semiconducting materials to improve the photocatalytic efficiency using various methods have gained importance. For this purpose graphitic like carbon nitride (g-C3N4) is a hopeful photocatalytic material for environmental remediation but its photogenerated charge carriers recombination rate limits g-C3N4 for practical applications. Hence, in the present work we synthesized heterojunction of g-C3N4/ZnO binary nanocomposites in 2D/1D by sonication assisted hydrothermal method. X-ray diffraction analysis confirms the formation of g-C3N4/ZnO binary nanocomposites. Transmission electron microscope analysis shows that the binary nanocomposites consists ZnO rods coupled with sheet like structure of g-C3N4. The band gap of g-C3N4 is 2.67 eV; however, the g-C3N4/ZnO binary nanocomposites shifts the band gap to 2.9 eV. Photoluminescence spectral analysis evidently shows the recombination rate of electron-hole pairs in the g-C3N4/ZnO binary nanocomposites is effectively reduced due to the formation of the heterojunction. The photoelectrochemical analysis shows that g-C3N4/ZnO binary nanocomposites enhance the photocurrent to 1.5 μA and effectively separate the electron-hole pairs when compared with that of bare ZnO and g-C3N4. Hence, the g-C3N4/ZnO binary nanocomposites effectively enhanced RhB dye degradation to 99% for 20 min and enhanced the 4-chlorophenol degradation to 90% for 40 min. under the sunlight irradiation.

Multi-site tunable emission of Eu2+ ions in Ca10Na(PO4)7 host

In this paper, three types of Eu2+ luminescent centers with emission bands at 407, 473, and 583 nm were found in the Ca10Na(PO4)7 phosphors with a β-Ca3(PO4)2-type structure. The relationship between the luminescent centers and metal sites was determined by the Rietveld refinements and photoluminescence spectral analysis. The concentration quenching behavior and the temperature dependent luminescence properties of Ca10Na(PO4)7:Eu2+ phosphors were investigated. The emission color and chromaticity coordinates of phosphors can be tuned by adjusting doping concentration and altering temperature.

S-rGO modified sulphur doped carbon nitride with mixed-dimensional hierarchical nanostructures of silver vanadate for the enhanced photocatalytic degradation of pollutants in divergent fields

A sheet on sheet (2D/2D) structure of highly conductive S-rGO on S-gC3N4 promote effective transfer of electrons for Cr(VI) reduction and subsequent degradation of organic pollutants. The photocatalytic activity of the 2D/2D hybrid material is significantly increased by the decoration of α-Ag3VO4 hollow nanoflowers through ultrasonic assisted Kirkendall effect. The inter-particle electronic coupling in hollow nanoflower leads to self-narrowing of the band gap. The in-situ fabrication of β-AgVO3 nanowires to form a quaternary catalyst enhanced the photocatalytic activity and corrosion inhibition by supporting a combined conventional and Z-scheme mechanism. This enhanced photocatalytic activity is due to the synergistic effects of heterostructured semiconductor photocatalysis, increased surface area, improved utilization of solar light due to hollow structure, decreased photocorrosion and the surface plasmon resonance(SPR) of Ag0. The photocatalytic activities of S-gC3N4/S-rGO/Ag3VO4/AgVO3(SGO-SGA-x) composite photocatalysts were measured by the degradation of methylene blue(MB), methyl Orange(MO), 2,4-dichlorophenoxy acetic acid(2,4-D) and Cr(VI) reduction under visible-NIR irradiation. Electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) spectral analysis indicated that the in-situ formation of β-AgVO3 from Ag3VO4 could efficiently promote the separation efficiency of photogenerated charge carriers. Our present work indicated that the photocatalytic activity can be significantly enhanced by judiciously designing the semiconductor nanomaterials.

Mixed-halide perovskite synthesis by chemical reaction and crystal nucleation under an optical potential

The development of new methods to engineer lead halide perovskite crystals with a controlled band gap and emission properties is an active subject in materials science and chemistry. We present the preparation of mixed-halide lead perovskites by spatially- and temporally- controlled chemical reactions and crystal growth under an optical potential in unsaturated precursor solutions. The crystals are characterized by transmission and photoluminescence spectral measurements and X-ray diffraction analysis. When compared with the spontaneous formation of multiple crystals in saturated precursor solutions, the optical potential creates large single crystals with a high chloride composition, providing distinct blue and green fluorescent crystals of chloride–bromide lead perovskites. We discuss the formation of mixed-halide perovskites from the viewpoints of an increased rate of chemical reaction via the formation and desolvation of precursor complexes and a decreased free energy potential.

Investigation of thermal and fluorescent properties of benzoxazole-linked triphenylamine-based co-polyimides

A series of novel fluorescent co-polyimides are obtained by combining N 1-(4-aminophenyl)- N 1-(4-(benzo[ d]oxazol-2-yl) phenyl) benzene-1,4-diamine and 4,4′-oxydianiline with four aromatic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydiphthalic anhydride, and 4,4 ′-(hexafluoroisopropylidene)diphthalic anhydride following conventional polycondensation method. The resultant co-polyimides are characterized by elemental, Fourier transform infrared spectral analysis and gel permeation chromatography. All newly prepared polyimides (PIs) exhibit shallow highest occupied molecular orbital energy levels in the range of −4.47 to −4.98 eV and have reasonable optical bandgaps. The photoluminescence spectral analysis shows blue to green emission in solution form. Thermal and solubility properties reveal that the PIs with pendant 4-(benzo[ d]oxazol-2-yl group linked to triphenylamine unit in polymer backbone impart not only good thermal stability but also appreciable solubility making these new co-polyimides versatile for multipurpose usage.

Pulsed laser ablation in liquid assisted growth of gold nanoparticles: Evaluation of structural and optical features

High purity gold (Au) nanoparticles (NPs) with desired morphology are demanding for various applications. Being simple, versatile, and cost-effective technique, PLAL is promising for the production of impurities free nanoparticles (NPs) of diverse materials. This paper reports the preparation and characterization of colloidal Au-NPs. Such Au-NPs were produced via PLAL route, wherein the Au target was immersed inside deionized water and ablated using a Q-switched Nd:YAG laser (wavelength 1064 nm and pulse width 8 ns). The structural, morphological, and optical characteristics of the as-synthesized Au-NPs were evaluated as a function of varied laser energies and repetition rates. Optical traits of Au-NPs were analyzed by ultraviolet–visible (UV–Vis) absorption, photoluminescence, and Raman spectroscopy. Surface plasmon resonance (SPR) absorbance at the excitation wavelength of 633 nm was recorded to find the shape of the Au-NPs. Attenuated total reflection infrared (ATR-IR) spectra was obtained to verify the achieved Au-NPs purity. High-resolution transmission electron micrographs approved the nucleation of spherical colloidal Au-NPs (mean diameter of 7 to 30 nm) in deionized water. The UV–Vis spectra of Au-NPs disclosed the occurrences of SPR peaks in the range of 521 to 524 nm accompanied by blue-shift. The UV absorption edge of the UV–Vis spectra was used to determine the optical band gap energies of the produced Au-NPs which were further confirmed by the photoluminescence spectral analyses. Present findings based on PLAL-assisted synthesis of pure Au-NPs may be beneficial for the development photocatalysis and solar cells.

First observation of reversible mechanochromism and chromaticity study on calcium–copper–titanate

AbstractFirst ever intriguing reversible mechanochromism espied in and chromaticity study on polycrystalline CaCu3Ti4O12 composition milled up to 16 hours are reported. The composition changes its color from blackish‐brown (un‐milled sample)‐reddish‐brown (1 hours milled sample)‐ heina‐green (6 hours milled sample)‐spinach‐green (16 hours milled sample) mainly due to the phase separation and corresponding change in band‐gap energy on milling. The UV‐Vis spectra show three observable absorption edges correspond to , , and , dyz transitions. A marked mechanochromic effect with crystallite size reduction is explained in the light of the difference in the site group symmetry of CuO4 and ligand‐metal charge transfer coupled with Cu2+ d‐d transitions. The observed mechanochromism is reflected and well supported by photoluminescence spectral analysis. CIE chromaticity coordinates are located in the light blue region for an un‐milled sample and violet color region for 6 hours milled sample. The profound correlation between the structural and optical properties has been revealed.

Luminescence kinetics of low temperature nano ZnTiO3:Eu3+ red spinel under NUV excitation

The present study discusses the synthesis and characterization of rare form of low temperature cubic spinel phase of ZnTiO3, whose synthesis is a challenging task for researchers. Powder XRD pattern confirms the formation of single phase spinel form of ZnTiO3 crystallizes in cubic lattice. The average crystallite size obtained from TEM analysis and Scherrer’ method is about 7–8 nm. Trivalent Eu ions in host lattice are confirmed by XPS spectroscopy. Photoluminescence spectral analysis infers that ZnTiO3:xEu3+ (x = 0.25%, 0.5%, 0.75%, 1%, 1.25%) nanophosphors show strong red emission corresponding to the forced electric dipole transition 5D0–7F2 under near UV excitation. Hypersensitive 5D0–7F2 transition indicates inversion antisymmetry crystal field around Eu3+ environment, favourable to improve red color purity. The type of multipolar interaction responsible for florescence quenching is also discussed. The color co-ordinate of all samples estimated from emission spectra is comparable to the national television standard committee value of red emission. The compositional dependence of Judd–Offlet parameters were evaluated and discussed. Eu doped spinels with defects associated structure shows better luminescent LED applications.

Enhanced optoelectronic properties of Mg doped Cu2O thin films prepared by nebulizer pyrolysis technique

In the present work, pure and magnesium doped Cu2O films were deposited on glass substrates by nebulizer spray pyrolysis method with doping concentrations of 0, 3, 5 and 7% at 280 °C. The as-prepared films were analyzed by XRD, AFM, laser Raman, UV–Vis, photoluminescence, Hall Effect measurements. An X-ray diffraction study clearly depicts that films are possessing polycrystalline nature with a cubic structure. The surface topological properties have been characterized using atomic force microscopy (AFM) which reveals nano shaped hill rock grains covered the surface of the substrate. Laser Raman spectroscopy studies confirm the peaks observed at 109, 148, 217, 416 and 514 cm−1 belong to Cu2O phase. UV–Vis spectrophotometer measurements show that the band gap is decreased from 2.25 to 1.9 eV for the increase of doping concentration Mg. Photoluminescence spectral analysis giving an emission peak at 630 nm confirmed the formation of cuprous oxide. The electrical studies showed that the films are of p-type. For the doping of 7% Mg concentration the Cu2O showed a resistivity 1.53 × 102 andhigh carrier concentration of 21.67 × 1016 cm−3. FTO/ZnO/Cu2O/Ag heterojunction was fabricated using 7% Mg doped Cu2O thin film, and found the open circuit voltage (Voc) as 0.25 V, short circuit current (Isc) as 0.225 × 10−4 A and the efficiency as 0.65% for the 7% Mg doped Cu2O thin film.

Construction of an in-situ Fenton-like system based on a g-C3N4 composite photocatalyst.

In this study, g-C3N4/PDI/Fe (gCPF) composite material was prepared by incorporating Fe ion on the composite catalyst of g-C3N4/PDI (gCP). X-ray photoelectron spectroscopy (XPS) showed that the Fe was successfully incorporated on the pristine g-C3N4/PDI. UV-vis diffuse reflectance spectrometry (UV-vis DRS) and Photoluminescence spectral (PL) analysis confirmed the enhancement of the visible absorption band following a decline in the photoelectron/hole recombination rate with gCPF. A preparatory experiment was performed on photocatalytic degradation of p-nitrophenol (PNP) to examine the activity of gCPF. Results obtained in the radical quenching and the electron paramagnetic resonance (EPR) spectroscopic studies indicated that an in-situ Fenton-like system has been successfully established and the main reactive oxygen species (ROS) changed from O2- to both O2- and OH in the gCPF system. However, a competition toward conduction band electrons between Fe3+ and O2 caused an inhibitory effect on PNP degradation. To overcome the effect, nitrilotriacetic acid (NTA) was introduced as a reducing agent for Fe3+. Upon adding NTA, the efficiency of PNP degradation greatly enhanced from 33 to 80%. The effect of initial pH, dosage of NTA and content of dissolved O2 on PNP degradation was also studied. The photocatalytic stability was confirmed by recycling experiments.

Shape-controlled synthesis of bare ZnO nanomaterials with improved photoactivity and photostability

ABSTRACTUnderstanding the growth mechanisms of nanomaterials usually leads to the successful preparation of targeted micro-structures with excellent properties. In this paper, flower-like and roughly spherical ZnO nanocrystals have been successfully synthesised through facile wet chemical methods, i.e. hydrothermal pathways and homogeneous precipitation method. The photocatalytic activities of the prepared photocatalysts were evaluated by degradation of rhodamine B (RhB) and phenol under ultraviolet (UV) irradiation. Remarkably, the ZnO powder via homogeneous precipitation (urea/Zn2+ = 2.0) exhibited better photocatalytic performance and photostability than those of flower-like ZnO substrate. The enhanced photocatalytic properties could be attributed to more active catalytic sites and effective separation of carriers, which were confirmed by low-temperature nitrogen adsorption, photocurrent responses, and photoluminescence spectral analysis. A possible mechanism for the excellent photocatalytic activity of ZnO substrates was proposed.

Effect of codoping Ce3+ on the luminescence properties of Sr9Mg1.5(PO4)7:Eu2+ orange–yellow phosphor

AbstractSr9Mg1.5(PO4)7:Eu2+ has recently been reported as a promising blue light‐excited orange–yellow phosphor that can be used in white LED device. Here, Ce3+‐codoping is found to be an effective strategy to improve the luminescence performance of Sr9Mg1.5(PO4)7:Eu2+ phosphor. The coexistence of Eu2+ and Eu3+ ions has been verified via photoluminescence spectral analysis. The reduction of Eu3+ to Eu2+ in Sr9Mg1.5(PO4)7 lattice cannot be completed in a reducing atmosphere, but can be promoted through codoping with Ce3+ ions to a great extent, which finally increase the effective concentration of Eu2+ in the crystal lattice. The Eu3+−Eu2+ reduction mechanism is analyzed using a charge compensation model. This work not only achieves enhanced luminescence of the Sr9Mg1.5(PO4)7:Eu2+ phosphor by codoping with Ce3+ ions, but also provides new insights into the design of Ce3+/Eu2+ codoped luminescent materials.

Time-resolved photoluminescence spectral analysis of phonon-assisted DAP and e-A recombination in N+B-doped n-type 4H-SiC epilayers

It is crucial to clarify the roles of phonon-assisted donor-acceptor pairs (DAPs) and free-to-acceptor (e-A) emissions in n-type 4H-SiC doped with nitrogen (N) and boron (B), where N and B induce the shallow donor and the D center (deep B) acceptor levels, respectively, in order to understand the complicated carrier recombination mechanism, as well as developing fluorescent SiC with a high color rendering index by controlling the ratio of the two overlapped emissions. Here, time-resolved photoluminescence (TRPL) spectral analyses were performed, in which phonon-assisted DAPs and e-A components were individually recognized. The D center-related green luminescence (1.6–2.8 eV) shows a non-exponential decay followed by a very slow decay in TRPL measurements at room temperature (RT). It emerges that most of the DAP emission intensities decay much faster than e-A emissions and contribute to what is initially fast and non-exponential decay at low temperatures, while the slow decay at RT is mainly from e-A emissions. At a much higher temperature, such as 473 K, only the e-A emission remains and the decay transforms from non-exponential to exponential behavior. High-temperature thermal quenching of e-A emissions exhibits different behaviors for samples with differing B doping concentrations. An activation energy of 0.6 eV was estimated from the Arrhenius plot of e-A emission intensity from a B-doped sample, which matches the D center level. This indicates that the hole thermal emission rate is greatly enhanced at a high temperature, which accelerates the decay of e-A emission intensity at high temperatures.

Photovoltaic performance of planar CH3NH3PbI3 perovskite solar cells based on CdS and high transmittance Cd(S,O) electron transport layers stacked with ZnO hole blocking layer

The chemical bath deposited n-type CdS and Cd(S,O) layer were implemented as electron transport (ET) layers integrated with ZnO hole blocking (HB) layer in the fabrication of planar CH3NH3PbI3 (MAPbI3) perovskite solar cells (PSC). The bonding environment and native defect structure of CdS and Cd(S,O) ET layers were established by Raman and photoluminescence spectral analysis. Optical studies showed that Cd(S,O) has higher UV–Vis transmittance and band edge threshold relative to CdS of similar thickness. The photovoltaic performance of the solar cells evaluated with CdS and Cd(S,O) ET layers of different 40-, 55-, and 80-nm thickness shows the effect of light intensity at the MAPbI3 photoabsorber and establishes the importance of native defects in electron extraction and transport in determining photoconversion efficiency (PCE). The effect of defect states in CdS and Cd(S,O) over corresponding J–V curves and fill factor of PSC device are described in terms of an energy band model. For 40-nm-thick Cd(S,O)/ZnO (ET/HB) layer, a PCE of 11.1% was achieved and compared with 9.18% for the CdS/ZnO (ET/HB) layer.

Synthesis, growth and characterization of a new NLO active chalcone derivative - 4-chloro-N-{3-[(2E)-3-(methoxyphenyl)prop-2-Enoyl]phenyl}benzamide monohydrate

Single crystal of a new Chalcone derivative “4-chloro-N-{3-[(2E)-3-(methoxyphenyl)prop-2-enoyl]phenyl}benzamide(CMPB)” was grown by slow evaporation method using Claisen-Schmidt and Schotten-Boumann Condensation reaction. XRD analysis was carried out to determine the structure, inter and intramolecular interactions of the compound. FTIR spectrum was taken to confirm the presence of functional groups in the compound. The number of protons and carbons present in the compound were determined by 1H and 13C NMR spectral analysis. The absorption and emission spectrum were analyzed by UV–Vis and Photoluminescence spectral analysis. The band gap energy was calculated using the cut off wavelength obtained from the UV–Vis spectrum. Thermal analysis TG/DSC was carried out to find the stability, melting point and decomposition point of the title compound. The SHG test shows that the efficiency of the crystal is 1.4 times as that of KDP which indicates the title compound has good NLO activity.

Effect of deposition temperature on key optoelectronic properties of electrodeposited cuprous oxide thin films

The cuprous oxide (Cu2O) thin films were electrodeposited with different reaction temperatures. The structural, morphological, optical, photoluminescence and photo response properties of the deposited films were analyzed. XRD analysis reveals cubic crystal structure for the deposited films with polycrystalline nature. The film deposited at room temperature possess high crystallite size of 37 nm. The surface morphology shows that by increasing the deposition temperature pyramid shaped morphology changes. Laser Raman study confirms the peaks 109, 148, 219, 415 and 635 cm−1 conforms the Cu2O phase formation. The band gap of the films are 2.02, 2.10 and 2.27 eV for the RT, 40 and 50 °C, respectively. The photoluminescence spectral analysis contains an emission peak at 618 nm confirm the formation of Cu2O. The photo response study confirms the ohmic nature of the films. The film electrodeposited at room temperature showed good I–V curve at the illumination of 300 W cm−2.

New Blue Light Emissive Polyazomethine(S) Containing Bromo-Triphenyl Units: Synthesis and Photophysics

ABSTRACT A series of bromo-substituted triphenylamine based poly(azomethine)s (P1-P3) were synthesized from the N1 -(4-aminophenyl)-N 1-(4-bromophenyl)benzene-1,4-diamine (DA) and aromatic dialdehydes. The viscosity of P1-P3 solutions (0.97 to 1.12 g dL−1) and molecular weight distribution analysis by Gel Permeation Chromatography (GPC) discloses the attainment of appreciable molecular weight. The optical transparency and fluorescence properties of the P1-P3 were explored by UV-vis and photoluminescence spectral analysis. From which it was concluded that the presence of 4-bromotriphenylamine and azomethine (CH = N) linkage in our synthesized materials are possibly responsible for the fluorescence with quantum efficiencies of 0.9–2.1 %.

BIOMIMETIC SYNTHESIS AND ANTIBACTERIAL PROPERTIES OF STRONTIUM OXIDE NANOPARTICLES USING OCIMUM SANCTUM LEAF EXTRACT

Objective: The investigation and synthesis of nanoparticles using green chemical methods is an emerging field due to ecologically derived materials. In the present study, the reaction under microwave irradiation technique is proposed for synthesizing the strontium oxide nanoparticles (SrO NPs) by reacting the strontium nitrate powder with Ocimum sanctum L. leaf extract followed by heat treatment at 500oC for 2 h.Methods: The crystalline nature, size, and morphological structure of the SrO powder sample were characterized by techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy, ultraviolet (UV)-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and photoluminescence (PL) spectral analysis. To investigate the antibacterial properties of SrO NPs, pathogens such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumonia, and Morganella morganii was tested in Mueller–Hinton disc diffusion method.Results: The particle size of the SrO NPs is calculated to be 42 nm using Debye–Scherrer equation. The SrO NPs exhibited absorption peak in the range of 250–350 nm centered at 274 nm in UV region. In addition, it is demonstrated that band gap energy was calculated to be 5.39 eV from Tauc’s plot. The SrO NPs has shown the efficient antibacterial effect by inhibiting zone against Gram-negative bacteria.Conclusion: The main aim of the study is to synthesize cost-effective and eco-friendly green synthesis of SrO NPs from the OS (O. sanctum) leaf extract and their characterization. The mechanism for the formation of SrO NPs in the presence of eugenol as reducing agent is also discussed. The present green chemical approach using plant-based materials for the synthesis of nanoparticles enhances the eco-friendliness, compatibility, effectiveness, and reduces the toxicity.

Novel SiQDs–MoS2 heterostructures with increasing solar absorption for the photocatalytic degradation of malachite green

Novel heterostructures based on silicon quantum dots and molybdenum disulfide nanosheets (SiQDs–MoS2) were synthesized by a hydrothermal method, in which the introduced SiQDs play a determining role in manipulating the morphology, phase and band structure of MoS2. The resultant SiQDs–MoS2 is uniform flowerlike 3D microspheres assembled from petallike 2D MoS2 nanosheets anchored with 0D SiQDs, possessing abundant active sites. Besides, the primary MoS2 nanosheets consist of both semiconductive 2H and metallic 1T phases accompanied with intralayer mesopores and expanded interlayer spacing, endowing the resulting architectures with effective electron transfer. Significantly, the as-synthesized SiQDs–MoS2 exhibits intense full solar-spectrum absorption, indicating efficient solar energy harvesting. First-principles calculations simulate similar increased spectral absorption of monolayer MoS2 adhered with a Si cluster, suggesting the existence of new energy states associated with the integration of SiQDs and MoS2 nanosheets as evidenced by photoluminescence (PL) spectral analysis. As expected, the current SiQDs–MoS2 heterostructures demonstrate substantial photocatalytic activity even under visible and near-infrared (NIR) light on degradation of malachite green (MG). The type II electronic structure of SiQDs–MoS2 was proposed, enabling sufficient photogenerated electrons and holes for the photocatalytic reactions. This study may establish a new frontier on the rational design and feasible development of the hybrid structures with the desirable morphologies, phase compositions and band structures for the catalysis and beyond.