Photoluminescence Peak Intensity Research Articles

Morphology-Dependent Photocatalytic Degradation of Organic Pollutant and Antibacterial Activity with CdS Nanostructures.

Efficient removal of organic pollutants from waste water by nanostructured photocatalysts has become an emerging research due to its importance in environmental remediation. Herein, CdS nanostructures with different morphologies i.e., spherical, nanopetal and rose-like have been synthesized by wet chemical method using TEA as a structure directing agent. The morphology, crystal structure, composition, surface area and optical properties of the nanostructures are investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Brunauer-Emment-Teller (BET) analyser, Ultraviolet-Visible (UV-Vis) absorption spectroscopy and Photoluminescence (PL) spectroscopy. XRD patterns indicate the existence of hexagonal phase of CdS in all the three morphologies. The SEM images confirm the morphological transformation of spherical CdS nanoparticles (NPs) to nanopetal and rose-like morphology with the increase in concentration of TEA in the synthesis process. UV-visible absorption spectra show that rose-like CdS nanostructure exhibits red-shift of absorption wavelength compared to spherical and nanopetal CdS nanostructures. The increase in intensity of PL peak of rose-like CdS at 576.6 nm compared to that of spherical and nanopetal CdS, confirms the presence of more S vacancies or defect states. The BET specific surface areas of spherical, nanopetal and rose-like CdS nanostructures are determined to be 4.18, 6.64 and 8.93 m₂/g, respectively. The EIS Nyquist plot confirms the higher electron transfer efficiency of rose-like CdS than that of spherical and nanopetal CdS. The photocatalytic activity of these three nanostructures are evaluated for the degradation of methylene blue (MB) dye in water solution under sunlight irradiation. Among the three structures, rose-like CdS nanostructure shows highest photocatalytic efficiency (96.5%) under sunlight irradiation within 120 min of sunlight irradiation. Antibacterial activity of the synthesized CdS nanostructures is performed against two Gram-positive and Gram-negative bacteria and rose-like CdS shows more activity against both types of bacteria than that of spherical and nanopetal CdS.

CNTs/Cf based counter electrode for highly efficient hole-transport-material-free perovskite solar cells

A carbon nanotubes (CNTs)/carbon fiber (Cf) has been prepared and used as a counter electrode (CE) for hole-transport-material-free perovskite solar cells (PSCs). It was found that CNTs/Cf material effectively increased the contact area between perovskite and carbon layer, correspondingly decreased the charge exchange resistance and enhanced hole extraction ability at perovskite/CE interface. In addition, hole transfer in CNTs/Cf CE was accelerated due to the existence of “highway” hole transfer path derived from CNTs/Cf structure, which reduced photoluminescence peak intensity. As a result, the PSC based on CNTs/Cf CE with high-efficiency hole extraction ability and fast hole transfer performance had a high power conversion efficiency (PCE) of 11.80 % compared with that of CNTs CE (8.93 %) and Cf CE (7.47 %).

Structural, morphological, optical analyses of Ni-doped CdS thin films and their photovoltaic performance in hybrid solar cells

This work reports influences of variation in Ni-doping on structural, morphological, and optical properties of CdS thin films and in their hybrid solar cell applications. X-ray diffraction data showed that increase of Ni-doping in CdS structure caused not only a broadening in CdS peak but also a decrease in the intensity of main cubic CdS peak. Morphological studies illustrated that lower amount of Ni-doping treatment firstly reduced the grain size of CdS thin films, whereas higher concentration of Ni-doping led to bigger grains. The best transparent CdS sample was achieved for 1 at% Ni-doping as 95% at 675 nm. Compared with CdS thin films (2.98 eV), bandwidths of Ni-doped CdS samples gradually increased and reached to 3.39 eV, which is due to the existence of strong quantum confinement effect. Photoluminescence (PL) data of the device demonstrated that the most efficient electron transfer was accomplished at CdS/P3HT interface for 1 at% Ni-doping because this device demonstrated the lowest PL peak intensity. Current density–voltage (J–V) characteristics of CdS-based device exhibited a power conversion efficiency (PCE) of 0.296% and it enhanced to 0.663% for device including 1 at% Ni atoms, which is most probably due to achievement of most efficient exciton dissociation between CdS and P3HT layers as approved by PL results. However, with increasing Ni-doping amount up to 3 at% and 5 at%, PCE values were in turn obtained as 0.131% and 0.208%, indicating a deterioration in PCE value of cells, which might be due to the less efficient exciton dissociation at the interface. Further increase of Ni-doping to 7 at% led to an efficiency value of 0.417%, which is still lower than that of 1 at% Ni-doped CdS-based device.

Effects of gap thickness and emitter location on the photoluminescence enhancement of monolayer MoS2 in a plasmonic nanoparticle-film coupled system

Abstract Plasmonic nanocavities comprised of metal film-coupled nanoparticles have emerged as a versatile nanophotonic platform benefiting from their ultrasmall mode volume and large Purcell factors. In the weak-coupling regime, the particle-film gap thickness affects the photoluminescence (PL) of quantum emitters sandwiched therein. Here, we investigated the Purcell effect-enhanced PL of monolayer MoS2 inserted in the gap of a gold nanoparticle (AuNP)–alumina (Al2O3)–gold film (Au Film) structure. Under confocal illumination by a 532 nm CW laser, we observed a 7-fold PL peak intensity enhancement for the cavity-sandwiched MoS2 at an optimal Al2O3 thickness of 5 nm, corresponding to a local PL enhancement of ∼350 by normalizing the actual illumination area to the cavity’s effective near-field enhancement area. Full-wave simulations reveal a counterintuitive fact that radiation enhancement comes from the non-central area of the cavity rather than the cavity center. By scanning an electric dipole across the nanocavity, we obtained an average radiation enhancement factor of about 65 for an Al2O3 spacer thickness of 4 nm, agreeing well with the experimental thickness and indicating further PL enhancement optimization. Our results indicate the importance of configuration optimization, emitter location and excitation condition when using such plasmonic nanocavities to modulate the radiation properties of quantum emitters.

Evaluation of photoluminescence from milk with various vitamin B2 concentrations

Concentrations of vitamin B2 in milk were evaluated based on photoluminescence (PL) peak intensities at around λ = 545 nm. PL was measured in a back-scattering configuration using a 3.2 mm diameter optical fibre bundle irradiated by ultra-violet LEDs, violet LEDs or a blue LED as the excitation light. The tip of the optical fibre bundle was dipped into commercially available whole milk, low-fat milk and non-fat milk. PL peaking at 545 nm was observed under LED irradiation. Vitamin B2 concentrations were measured using a standard addition method and a calibration curve method. Deviation between the vitamin B2 concentration measured by PL using a standard addition method and those by HPLC technique varied with wavelength of excitation light and was smallest with violet LED (405 nm) excitation. The standard deviation of results measured by PL using a calibration curve method was better than those using a standard addition method.

Influences of thickness and temperature of low temperature GaAs buffer layer on two-step MOVPE grown GaAs/Ge heterostructures

We investigate influence of GaAs buffer layer (BL) growth parameters such as temperature and thickness on the structural, morphological, crystalline and optical quality of metal organic vapor phase epitaxy (MOVPE) grown heterostructures of GaAs on Ge. It was found that the optimal BL conditions significantly decrease the effects of anti-phase boundaries (APBs) even when grown on offcut Ge substrate by two-step growth technique with AsH3 pre-flow to promote double atomic step formation. It is observed that as the growth temperature increases, the growth rate of the GaAs BL increases, too. Improvement on the structural quality is observed up to BLs temperature of 535 °C, then it decreases. On the other hand, as the different thick BLs, 12, 25, 75 nm are considered, the epilayer grown on the 25 nm thick BL has shown the lowest full width at half maximum (FWHM) value, large photoluminescence peak intensity and internal quantum efficiency (IQE).

Ag nanoparticles localised surface plasmon field regulated spectral characteristics of Ho3+-doped phosphate-based glass-ceramic

The holmium ion (Ho3+)- activated phosphate-based glass-ceramics with silver nanoparticles (Ag NPs) inclusion were prepared using the standard melt-quenching. The samples were characterised to evaluate the effects of different Ag NPs contents on their structure, microstructure and optical properties. The XRD pattern of the as-quenched samples revealed their glass-ceramic nature. The FTIR and Raman analyses showed the modification of the glass-ceramics network structure due to the embedment of Ag NPs. The TEM and HRTEM images together with the localized surface plasmon resonance (LSPR) absorption bands of the glass-ceramics confirmed the existence of Ag NPs inside the host matrix. The complex impedance analyses of the glass-ceramics suggested the glassy phase dominance in the host network. The photoluminescence (PL) peak intensities were significantly enhanced due to the influence of Ag NPs enabled LSPR effects. The PL decay curve analysis of the glass-ceramics indicated the effect of Ag NPs mediated amplified local electric field and energy transfer from the Ag NPs to Ho3+, a mechanism responsible for the optical traits improvement. The achieved branching ratio and stimulated emission cross-section of the optimum glass-ceramic for the three PL peaks were 73.88% and 46.68 × 10−21 cm2 (green); 83.97% and 41.12 × 10−21 cm2 (red); and 71.40% and 36.95 × 10−21 cm2 (IR). Based on the obtained findings, a structural-optical correlation was established.

Spectral features of Ho3+ -doped boro-phosphate glass-ceramics: Role of Ag nanoparticles sensitization

The development of the metallic nanoparticles-sensitised and lanthanides-doped multi-functional luminescent glass-ceramics (GCs) for advanced applications remains challenging. In this perception, the role of varying silver nanoparticle (Ag NP) concentration on the structures, microstructures and optical properties of some new class of zinc-sulfo-boro-phosphate GCs activated with holmium ions (Ho3+) was analysed using different mechanisms. These GCs were prepared by the standard melt-quenching and thoroughly characterised using various analytic means. The XRD patterns of the as-quenched samples confirmed their GC nature. The Judd–Ofelt (J–O) intensity parameters and radiative properties plus the CIE colour coordinates for these GCs were evaluated using the measured photoluminescence (PL) spectral data. The absorption spectra of the GCs revealed 13 peaks associated to the Ho3+ transitions and the absorption edge data were used to calculate the optical band gap and Urbach energy. The PL spectra of the titled GCs revealed an intense green and red emission peak distinctive of the electronic transitions in Ho3+. Despite the strong mediation of the Ag NPs LSPR on the PL emission of Ho3+, the structural alterations in the GCs network played a dominant role towards the PL peak intensity quenching. The density, Raman, FTIR and impedance spectral analyses exhibited the formation of more bridging oxygen and significant reduction of the nonbridging oxygen in the GC matrix due to the addition of Ag NPs, leading to the Ho3+ clustering. An interrelationship between the structural and optical attributes in these GCs was ascertained for the first time. The proposed GC compositions are established to be beneficial for the advancement of the novel luminescent materials for various photonic and optoelectronic applications.

Effect of Ocimum gratissimum plant leaf extract concentration and annealing temperature on the structure and optical properties of synthesized zinc oxide nanoparticles

Zinc oxide nanoparticles biosynthesized using two concentrations of Ocimum gratissimum (Og) plant leaf extracts were annealed at two different temperatures. Their UV-Vis absorbance peaks at 372 nm - 375 nm indicate a blue shift in excitonic absorption and their optical energy band gap values were in the range 3.22 eV – 3.31 eV. SEM images show the nanoparticles to be polydispersed and of a wide range of sizes with smaller nanoparticles clustering around bigger micrometer- sized ones with sharp edges. An annealing temperature of 400 resulted in the sintering of the nanoparticles but nanoparticles annealed at 250 had porous surfaces suggesting a possible use in gas sensor applications. XRD patterns show that the ZnO nanoparticles have the hexagonal wurtzite structure and are of good crystalline structure. Obtained crystallite sizes increased with annealing temperature and were in the range 14 nm to 29 nm. FTIR spectra show phenols, amines and aldehydes as the available reducing agents involved in the nanoparticle synthesis. The photoluminescence (PL) spectra show two emission peaks: a UV emission peak at 369 -381 nm indicating that the zinc oxide nanoparticles exhibited band-edge photoluminescence and a green emission peak at 523 nm – 538 nm suggesting the presence of defects from singly ionized oxygen vacancies. The PL peak intensities were dependent on the annealing temperatures with the UV- emission peaks for higher annealing temperatures exhibiting a spectral shift towards lower wavelengths. Plant leaf extracts concentration and the annealing temperatures used affect the structure and optical properties of the synthesized ZnO nanoparticles.

Non-contact localized probing of ferroelectric phase transitions in Li+/Er3+:BaTiO3 ceramics using fluorescence abnormalities

Fluorescence abnormalities associated with the ferroelectric phase transition of Li+/Er3+:BaTiO3 (BLET) ceramics were studied based on photoluminescence (PL) spectra. Sharp changes were found in the integrated intensities, peak intensities, and fluorescence intensity ratios of both upconversion spectra (2H11/2/4S3/2−4I15/2) and downconversion infrared spectra (4I13/2−4I15/2) around the ferroelectric-paraelectric phase transition temperature in BLET ceramics under the excitation of a 980 nm laser. All changes happened within the temperature interval of 126 °C–130 °C. The relative changing rate (RCR) was adopted to quantitatively describe this structure-sensitive PL. For the system under study, the maximum RCR occurs for the PL peak intensity at 542.7 nm.

Solution processed graphene quantum dots decorated ZnO nanoflowers for mediating photoluminescence

We report the fabrication of hybridization between graphene quantum dots (GQDs) and ZnO nanoflowers (NFs) for mediating photoluminescence by using a straightforward solution-based technique. Hydrothermally grown two-dimensional ZnO NFs played an essential role in assembling GQDs. The large surface area to volume ratio of ZnO NFs led to a highly dense distribution of GQDs, giving rise to photoluminescence (PL) emission at around 442 nm from GQDs and the synergic effects. Thus, GQDs/ZnO hybrid results in strong and broad PL over the spectral range from near UV to red region. We also suggested that an energy interaction between GQDs and various defect sites in ZnO NFs can promote the radiative recombination of both components, thereby providing PL peak intensities more than two times higher than individual components. Fabricated GQDs/ZnO heterojunctions on both soft and hard substrates emit similar intense and wide PL spectrum under ultraviolet irradiation, indicating that this heterojunction can consider as a promising platform for flexible and transparent optoelectronic applications.

Yellow emissive Se,N-codoped carbon dots toward sensitive fluorescence assay of crystal violet

Crystal violet (CV), a hazardous dye, poses a serious threat to the environment and human health. This motivates us to develop a facile method for its sensitive detection. Herein, we demonstrate a rapid sensing of CV using a novel fluorescent nanomaterial, yellow emissive Se,N-codoped carbon dots (CDs). CDs with an intense photoluminescence peak at 566 nm are synthesized by a hydrothermal technique using selenourea and o-phenylenediamine as precursors. This material shows a high quantum yield of up to 16.7 %. It is found that the yellow fluorescence of CDs can be selectively quenched by CV, which makes them promising for CV sensing. The linearity is obeyed in the range of 0.02–1.60 μM, and the limit of detection is as low as 7.3 nM. After detailed investigations, the inner filter effect is proposed to be the sensing mechanism. For practical usage, the newly built method is applied to determine the trace amount of CV in fish tissue samples, and satisfactory results are obtained.

Optical and surface properties of CdSe thin films prepared by sol-gel spin coating method

In this work, L-cysteine capped CdSe nanocrystals thin films were grown on glass substrate by using spin-coating method. The annealing temperature effect on structural, morphological, and optical properties of CdSe thin film is investigated by X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Atomic force microscopy (AFM), UV–Vis and photoluminescence (PL) techniques. XRD analysis showed crystallization and phase transformation of CdSe thin films from cubic (Zinc Blende, β-CdSe) to hexagonal (Wurtzite, α-CdSe) structure are obtained after air-annealing at 250 °C during 30 min. DSC analysis showed the exothermic peak in the range of 170–225 °C, indicating the structural phase transformation of CdSe thin film. AFM analysis exhibited a change in the surface roughness of thin films and the shape of CdSe nanoparticles from hemispherical nanocrystals into microrods as a function of annealing temperature. The surface and volume energy loss (VELF and SELF) functions show different dependences on the incident photon energy for the CdSe films in the energy range 1.5–4 eV as a function of air-annealing temperature. The dispersive optical parameters such as refractive index (n), extinction coefficient (k), and the dielectric constants were found to vary with the annealing temperature. PL measurements showed that the increase in the annealing temperature up to 200 °C results an improvement in the crystalline quality of the CdSe thin film, a decrease in their optical band gap, and an enhancement in the PL peak intensity.

Effect of KOH passivation for top-down fabricated InGaN nanowire light emitting diodes

Gallium nitride (GaN) nanowire (NW) light emitting diodes (LEDs) are promising candidates for microdisplay applications due to smaller dimensions and potential for novel integration approaches. For the commonly adopted top-down GaN NW fabrication, the required dry etching steps tend to result in surface states, leading to reduced radiative recombination rates in LEDs. To passivate the surface and tune the diameter of the NWs, hydroxyl-based chemicals such as potassium hydroxide (KOH) are widely used to treat the surface of these nanostructures. However, studies on the effects of temperature, concentration, and the damage recovery aspects of hydroxyl etching of GaN NWs are very scarce. These etching parameters are of great importance for device performance. Here, these effects are explored thoroughly with a focus on the correlation of InGaN/GaN NW LED performances to KOH etching temperature, concentration, and time, together with a fundamental crystallographic analysis. The KOH concentration resulting in total removal of the NW base tapering and a collimated etch profile for InGaN NW LEDs was found to be 0.8 wt. % at a temperature of 45 °C. A 20 min etch at 23 °C with a 0.1 wt. % KOH concentration will remove surface states from a top-down fabricated NW LED to recover up to 90% of the peak photoluminescence (PL) intensity lost by the dry etch step. The oscillation behavior in PL intensity with regard to the KOH etch time has been demonstrated in InGaN/GaN NW LEDs for the first time, which will shed light upon the design and passivation of these devices for microdisplays.

Study of Oxidation and Polarization-Dependent Optical Properties of Environmentally Stable Layered GaTe Using a Novel Passivation Approach.

Emerging two-dimensional gallium chalcogenides, such as gallium telluride (GaTe), are considered promising layered semiconductors that can serve as vital building blocks towards the implementation of nanodevices in the fields of nanoelectronics, optoelectronics, and quantum photonics. However, oxidation-induced electronic, structural, and optical changes observed in ambient-exposed gallium chalcogenides need to be further investigated and addressed. Herein, we report on the thickness-dependent effect of air exposure on the Raman and photoluminescence (PL) properties of GaTe flakes, with thicknesses spanning in the range of a few layers to 100 nm. We have developed a novel chemical passivation that results in complete encapsulation of the as-exfoliated GaTe flakes in ultrathin hydrogen–silsesquioxane (HSQ) film. A combination of correlation and comparison of Raman and PL studies reveal that the HSQ-capped GaTe flakes are effectively protected from oxidation in air ambient over the studied-period of one year, and thus, preserving their structural and optical characteristics. This contrasts with the behavior of uncapped GaTe, where we observe a significant reduction of the GaTe-related PL (~100×) and Raman (~4×) peak intensities for the few-layered flakes over a period of few days. The time-evolution of the Raman spectra in uncapped GaTe is accompanied by the appearance of two new prominent broad peaks at ~130 cm−1 and ~146 cm−1, which are attributed to the formation of polycrystalline tellurium, due to oxidation of ambient-exposed GaTe. Furthermore, and by leveraging this novel passivation, we were able to explore the optical anisotropy of HSQ-capped GaTe flakes. This is caused by the one-dimensional-like nature of the GaTe layer, as the layer comprises Ga–Ga chains extending along the b-axis direction. In concurrence with high-resolution transmission electron microscopy analysis, polarization-dependent PL spectroscopy was used to identify the b-axis crystal direction in HSQ-capped GaTe flakes with various thicknesses over a range of wavelengths (458 nm–633 nm). Thus, our novel surface-passivation offers a new approach to explore and reveal the physical properties of the layered GaTe, with the potential of fabricating reliable polarization-dependent nanophotonics with structural and optical stability.

MOCVD Growth and Characterization of InN Quantum Dots

Metal‐polar InN quantum dots (QDs) are grown by metalorganic chemical vapor deposition at temperatures between 500 and 600 °C. Dot densities between 4 × 108 and 4 × 1010 cm−2 are observed. InN QDs exhibit room‐temperature photoluminescence (PL) with peak wavelengths from 1100 to >1550 nm. GaN cap layers grown on InN QDs have little effect on either peak PL wavelength or intensity, a step toward creating multilayer structures for InN QD devices.

Electrical and optical properties of the specimens with graphene quantum dots prepared by different number of wet transfer

Graphene quantum dots (GQDs) are grown on the copper foil substrate by the chemical vapor deposition (CVD) synthesis. 1–3 wet transfer numbers are then used in the preparations of the GQDs/glass substrate in order to improve the density and uniformity of GQDs via the stacking of multiple layers. The CH4 input time, flow rate, and the number of wet transfer are determined to obtain the optimum conditions in electrical (resistivity) and optical (transmittance) properties. The multilayered graphene is characteristically close to the graphite-like material. The G-band peak intensity in Raman analyses is varied proportional to the density of GQDs. Increasing the wet transfer number can lead to increases in the mean diameter of GQDs and the amount of oxygen vacancies, thus resulting in the rise of carrier concentration and the lowering of carrier mobility. The resistivity varying with the wet transfer number is inversely proportional to the density of GQDs. A bandgap reduction can bring in the lowerings of photoluminescence peak intensities. The specimen with 2 wet transfers has the lowest resistivity and the second highest transmittance of these specimens. GQDs can bring in a significant reduction of resistivity compared to the same substrate without GQD.

Gamma irradiation dose dependent nano-structural, optical and impedance spectroscopy of PdS thin films

Gamma irradiation is recognized to modify the properties of thin films. In the present work, the effects of gamma irradiation on the nano-structural electrical and optical properties as of function of radiation dose has been studied. The PdS thin films deposited on glass substrate by successive ion layer adsorption and reaction (SILAR). The deposited thin films were irradiated by the gamma radiation with the 60Co for the Gamma dose range from 0 to 100 kGy. As deposited and gamma irradiated PdS thin films were investigated by impedance spectroscopy, X-ray diffraction, energy dispersive X-ray, scanning electron microscopy and Photoluminescence. The X-ray diffraction patterns exhibited a tetragonal structure of PdS thin films before after gamma irradiation, and demonstrated the changes in crystallinity, dislocation density, crystallite size and micro-strain. Field emission scanning electron microscopy and energy dispersive X-ray study conformed atomic composition of PdS thin film (1:1 ratio of Pd:S) and revealed that shape and size of grain depend on dose of gamma irradiation. Photoluminescence peak are found to be shifted to longer wavelength, intensity and width of photoluminescence peak increased for the gamma irradiated samples with increasing gamma dose. Impedance spectroscopy revealed that the enhancement of charge carrier density of irradiated PdS thin films increased linearly with gamma dose. The achieved results prove that gamma irradiation has superficial influence on nano-structural, optical and electrical properties of the deposited PdS thin films.

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.

Insights into the Photoassisted Electrocatalytic Reduction of CO2 over a Two‐dimensional MoS2 Nanostructure Loaded on SnO2 Nanoparticles

AbstractPhotoelectrochemical reduction of CO2 to value‐added chemicals and fuels is an attractive strategy to store renewable energy and mitigate greenhouse gas emissions. In this study, based on the density functional theory (DFT) calculation, a two‐dimensional nanostructure MoS2 loaded on SnO2 nanoparticles (MS/SON) was prepared for photoassisted electrocatalytic reduction of CO2 to HCOOH through a two‐step process of facile hydrothermal and pyrolysis method. Through physical structure characterization and photoelectric performance test, the results indicated that the 5 % MS/SON exhibits exclusive HCOOH selectivity, the maximum FE is 43.8 %, the current density reached to 9 mA cm−2 at −1.4 V and the photocurrent value is 12.5 μA cm−2 under 0.5 V bias. The overpotential is as low as 245 mV. Besides, after the introduction of MoS2, there is a red shift in the adsorption band edge from 380 nm to 500 nm, indicating an enhancement of light response; the peak intensity of photoluminescence (PL) decreased, showing that the electron and hole are effectively separated; the values of electrochemical impedance spectroscopy (EIS) and Tafel plots (70 mV dec−1) were smaller than other ratios, demonstrating that the faster charge transfer rate; the proper introduction of MoS2 increased the specific surface area from 47.64 m2 g−1 to 55.99 m2 g−1, which was helpful to expand the number of active sites. It is demonstrated that MS/SON is an excellent CO2 reduction material.