Light Absorption Spectra Research Articles

Light harvesting S-scheme g-C3N4/TiO2/M photocatalysts for efficient removal of hazardous moxifloxacin

The development of advanced photocatalysts with enhanced efficiency for environmental remediation is critical for addressing persistent organic pollutants like Moxifloxacin. In this study, we present a novel S-scheme heterojunction g-C3N4/TiO2/M photocatalyst designed to optimize light harvesting and charge separation for the effective degradation of Moxifloxacin. The innovative S-scheme configuration enables superior charge transfer dynamics by retaining potent photogenerated electrons in the conduction band of TiO2 and holes in the valence band of g-C3N4, significantly improving photocatalytic performance compared to conventional Type-II systems. Heterogeneous photocatalysis, particularly using TiO2-based materials, offers a promising approach. Here, we synthesized TiO2 hybridized with metal-doped g-C3N4 (GCNTM) via a simple hydrothermal method. The fabricated nanocomposites were characterized using SEM, XRD, FTIR, and UV–Vis (DRS). These GCNTM nanocomposites were employed for the degradation of hazardous Moxifloxacin (MXF) under visible light. Detailed analysis of the photocatalytic mechanism reveals that the synergistic interaction between g-C3N4, TiO2, and the co-catalyst M not only broadens the light absorption spectrum but also enhances the separation and lifespan of charge carriers. Among the synthesized materials, GCNTLa demonstrated the highest degradation efficiency, achieving 96 % removal of MXF. This enhanced activity is attributed to the effective suppression of charge recombination, leading to the generation of reactive species responsible for MXF degradation. Additionally, GCNTM showed remarkable stability and reusability, with only a 6 % reduction in efficiency after five cycles, confirming its high reusability and mechanical stability. Our S-scheme photocatalyst demonstrates a marked increase in the degradation rate of Moxifloxacin under visible light irradiation, highlighting its potential for practical environmental applications.

Visible-Light-Activated TiO2-Based Photocatalysts for the Inactivation of Pathogenic Bacteria

Pathogenic bacteria in the environment pose a significant threat to public health. Titanium dioxide (TiO2)-based photocatalysts have emerged as a promising solution due to their potent antimicrobial effects under visible light and their generally eco-friendly properties. This review focuses on the antibacterial properties of visible-light-activated, TiO2-based photocatalysts against pathogenic bacteria and explores the factors influencing their efficacy. Various TiO2 modification strategies are discussed, including doping with non-metals, creating structure defects, combining narrow-banded semiconductors, etc., to extend the light absorption spectrum from the UV to the visible light region. The factors affecting bacterial inactivation, and the underlying mechanisms are elucidated. Although certain modified TiO2 nanoparticles (NPs) show antibacterial activities in the dark, they exhibit much higher antibacterial efficacies under visible light, especially with higher light intensity. Doping TiO2 with elements such as N, S, Ce, Bi, etc., or introducing surface defects in TiO2 NPs without doping, can effectively inactivate various pathogenic bacteria, including multidrug-resistant bacteria, under visible light. These surface modifications are advantageous in their simplicity and cost-effectiveness in synthesis. Additionally, TiO2 can be coupled with narrow-banded semiconductors, resulting in narrower band gaps and enhanced photocatalytic efficiency and antibacterial activities under visible light. This information aids in understanding the current technologies for developing visible-light-driven, TiO2-based photocatalysts and their application in inactivating pathogenic bacteria in the environment.

Triple-junction Dion–Jacobson perovskite tandem solar cells: advancing efficiency via interface optimization and broadened light absorption spectrum

Abstract Dion-Jacobson (DJ) perovskites have emerged as game-changers in the world of photovoltaics due to their unique combination of advantages like cost-effective fabrication, tailorable bandgap, and exceptional efficiency. Further, in this study, MXene contacts have been utilized with 2D-perovskites solar cells to leverage the advantages of both, leading to improved stability, superior charge transport, and adjustable energy bandgap without the occurrence of pinhole effects. To further tap into the immense potential of perovskites, this study explores the power of a triple-junction All DJ perovskite tandem solar cell (ADJT-PSC) architecture. This design captures a broader spectrum of sunlight, maximizing energy harvesting and unlocking new possibilities for photovoltaic devices. In this symphony of light and power, 1.5-pentamethylenediamine (PeDA) methylammonium lead iodide (PeDAMAPb2I7) (1.98 eV), PeDAMA5Pb6I19 (1.6 eV), CsLaTa2Se7 (1.1 eV) take as the absorber layers in the top, middle, and bottom subcells, respectively. Moreover, optimizing the thickness of each perovskite layer is crucial for maximizing efficiency. This study conducted a thorough analysis and identified the ideal 350 nm/550 nm/200 nm thicknesses for the top/middle/bottom layers, respectively. Furthermore, the study explored the art of doping variation in the electron and hole transport layers. By meticulously adjusting the doping levels, ADJT-PSC can achieve a maximum efficiency of 35%.

Preparing Ruthenium Complex-Contained DaTp COFs via π-π Interactions for Visible-Light-Driven Photocatalytic Hydrogen Peroxide Production.

Hydrogen peroxide (H2O2) is a crucial energy carrier with growing significance in sustainable energy systems. Covalent organic frameworks (COFs) have recently emerged as promising materials for efficient H2O2 photosynthesis, while transition-metal complexes are recognized for their efficacy as molecular photocatalysts in H2O2 production. This study introduces a novel π-π interaction strategy to immobilize ruthenium complexes into COFs, using DaTp COF as a model system. This approach significantly enhances the photocatalytic activity for H2O2 production, achieving an initial rate of 3276 μmol g-1 h-1 without using scavengers under visible-light irradiation (λ > 420 nm). Notably, incorporating ruthenium complexes optimizes the oxygen reduction reaction pathways, shifting from a less efficient four-electron process to a more efficient two-electron process. Density functional theory calculations further reveal that ruthenium complexes not only broaden the light absorption spectrum of the COF but also increase water affinity, directly contributing to H2O2 generation. These findings offer a strategic framework for designing and enhancing COFs in H2O2 photosynthesis applications.

Cu/S Co-anchoring junction boosted the photogenerated carrier separation efficiency in g-C3N5 for enhanced H2 evolution

C3N5 is emerging as an important visible light catalyst because of its narrow band gap, nontoxicity and thermal stability. Herein, sulfur-doped g-C3N5 (SCN) was prepared by copolymerization of thioacetamide (TAA) and 3-amino-1,2,4-triazole (3-AT). Then copper nanoparticles (Cu NPs) were anchored onto the SCN framework, resulting in the formation of Cu/SCN. It was found that the average H2 production rate of SCN and Cu/SCN was 0.76 and 1.34 mmol g−1 h−1, which was much higher than that of C3N5, respectively. Acting as a new active spots, sulfur doping effectively reduces the band gap of g-C3N5, and the formation of S-Cu bonds further creates an efficient electron transport pathway. As a result, Cu/SCN possesses a broader visible light absorption spectrum, stronger reduction capability, and greater efficiency in photo-induced carrier separation and transfer. Therefore, this work introduces a novel strategy for design of high efficiency photocatalytic H2 evolution carbon nitride through non-noble metal and sulfur anchoring junction.

Experimental and calculation investigations of the photocatalytic selective and performance for CO2 reduction by cobalt-doped Bi4O5Br2 nanosheets

This study delves into the photocatalytic process of an innovative Co-doped Bi4O5Br2 material synthesized through a straightforward process. Experimental and theoretical findings corroborate that cobalt doping remarkably enhances the CO2 reduction capability of Bi4O5Br2 catalysts under visible light. Findings indicate that Co-doped Bi4O5Br2 exhibits substantial advantages over its pristine counterpart in photocatalytic CO2 reduction. Notably, the catalyst with 4 at.% Co doping demonstrates the highest photocatalytic CO2 reduction efficiency, achieving CO and methane production activities of up to 9.46 and 0.20 μmol/g/h, respectively. Furthermore, the low activation energy for CO2 reduction in Co-doped Bi4O5Br2, as indicated by reaction pathways calculations, facilitates the process. Detailed experimental results reveal that Co incorporation does not alter the surface morphology or the crystalline phase of the photocatalyst. The superior efficiency of Co-doped Bi4O5Br2 is attributed to multiple factors: a narrow band gap, expanded visible light absorption spectrum, greater absorption intensity within the visible range, and enhanced separation efficiency of photogenerated electrons and holes compared to pristine Bi4O5Br2. This highlights the practical application of Co-doped Bi4O5Br2 for enhancing photocatalytic performance, supporting future advancements in solar energy utilization and the creation of high-value chemical products.

The addition of Bi2WO6 nanoparticles to polyvinyl alcohol film: Improvements in optical, mechanical, and electrical properties

This study deals with the influence of adding Bi2WO6 (BWO) nanoparticles on the optical, structural, dielectric, and mechanical properties of polyvinyl alcohol (PVA). BWO nanoparticles synthesized by solvothermal method were characterized by X-Ray diffraction (XRD) and scanning electron microscope (SEM-EDS). The thick film nanocomposites were analyzed by Fourier Transformed Infrared (FTIR) spectrometer, XRD device, SEM, atomic force microscope (AFM), ultraviolet visible (UV–Vis) spectrophotometer, impedance analyzer, and tensile test machine. While FTIR analyses confirmed the formation of composite structure and the presence of BWO in the composites, AFM views indicated the reduced roughness for composites. Additionally, the UV–Vis light absorption spectra revealed a narrowed band gap in the composites. Moreover, with increasing BWO contribution, gradual increases were recorded in Young's modulus, toughness and % breaking strain parameters. The frequency dependent dielectric properties was also shown that the energy storage ability of the PVA matrix enhances 25 % and 50 % due to 2 % and 3 % BWO additives, respectively. However, the composite with higher ε′ and lower ε″ values than the pure PVA in the entire frequency range was the 2 % BWO-doped nanocomposite. Based on the serious and simultaneously improvements in electrical, optical and mechanical properties, it can be suggested that 2 % BWO additive provides the opportunity to expand the application area of PVA synergistically.

Environmentally friendly, high near-infrared reflection green pigments for thermal insulation

In this paper, TiO2 and MgAl-LDHs were coated on yellow pigment hydroxyl iron oxide (FeOOH) with sol-gel and hydrothermal synthesis method respectively to prepare loaded yellow pigment (FT8M0.25). Then, phthalocyanine blue (CuPc) was combined with FT8M0.25 to prepare composite green pigment (FT8M0.25Px). The results indicate the FT8M0.25Px has the structural characteristics of hydrotalcites and CuPc. The surface of FeOOH pigment has a clear TiO2 coating layer and MgAl-LDHs flake structure. KPFM analysis indicate that there is electron transfer between the interfaces of pigments. According to the analysis of color performance and near-infrared reflectance (NIR), the FT8M0.25P0.13 (a*=-12.98) is greener than that of Cr2O3 (a*=-6.65). The NIR of FT8M0.25P0.13 is as high as 73.54 %. The visible light absorption spectrum characteristics determine the color of the pigments, and there is electron transfer between the interfaces of each group. The formation of multi-level interfaces and the resulting multiple light reflections increase the reflectivity of the pigment. The developed coating achieved a considerable temperature difference of 20 °C before and after the coating surface with excellent photostability and reusability, which makes it possible for pigments to replace chromium containing pigments and be used as energy-saving cold pigments.

Accurate and efficient electronic structure calculations of semiconductor heterostructures using GGA-1/2 formalism

We have demonstrated that the electronic structures of interfaces between semiconductors, dislocations in solids, and real-size quantum dots—which are challenging to simulate due to the large number of atoms involved—can be calculated in a cost-effective and accurate manner through the implementation of the GGA-1/2 formalism with a pseudo-atomic orbital (PAO) basis. The band offsets, particularly those of the valence bands, of four interfaces (InAs/AlSb, ZnSe/ZnS, GaN/SiO2, and anatase/rutile) and the light absorption spectrum of a ZnSe/ZnS core/shell quantum dot with a diameter of 4.9 nm and the redshift due to the shell were accurately reproduced. The combination of the PAO basis and half-occupation method represents a highly realistic approach to studying the electronic structure of semiconductor heterostructures, as it allows for the relaxation of constraints in the size of the structural model while accurately predicting band edge positions.

Effective removal of organic compounds by g-C3N4-AQ/Fe(III) via photocatalytic oxidation and photochemical cycling of iron

Anthraquinone-anchored graphitic carbon nitride (denoted as g-C3N4-AQ), which has been reported in the photochemical production of H2O2, demonstrated significant visible light photocatalytic activity with Fe(III) for the degradation of organic compounds. The synthesized g-C3N4-AQ exhibited a light absorption spectrum and crystallinity comparable to that of pristine g-C3N4. FT-IR and XPS analyses confirmed the covalent bonding between AQ and g-C3N4. The synthesized g-C3N4-AQ generated 12 μM of H2O2 within 2 h under visible light illumination, a quantity negligible for the degradation of organic compounds. However, in the combination with Fe(III), the system successfully degraded organic compounds, achieving degradation of 88 – 99 % in the presence of dissolved oxygen. It was also observed that the photochemical activity of g-C3N4-AQ/Fe(III) was non-selective towards the target organic compounds. Intriguingly, the visible light-illuminated g-C3N4-AQ/Fe(III) selectively degraded target organic compounds in the absence of dissolved oxygen. Experimental work employing reactive oxidant scavengers and oxidant probes revealed that •OH is the main reactive species responsible for the degradation of organic compounds in the presence of dissolved oxygen, whereas in its absence, the hole acts as the primary oxidant in the selective degradation of organic compounds. This finding provides important insights into the application of the g-C3N4-AQ/Fe(III) system for effective micropollutant removal.

식품 신선도 모니터링을 위한 천연 염료와 고분자 기반의 색변환 가스 인디케이터

In this study, we developed colorimetric gas indicators that respond to exposure to ammonia gas, which may occur due to food spoilage. We prepared bio-compatible and eco-friendly anthocyanin dye and cellulose acetate (CA) polymer to fabricate the gas indicators. The color of anthocyanin-doped CA films changed depending on the time of exposure to ammonia gas or the concentration of the gas, which can be quantitatively analyzed by measuring the light absorption spectrum of the indicators. As the color of the indicator changed from purple to blue when exposed to ammonia gas, the absorption peak wavelength red-shifted from 535 nm to 615 nm. By enclosing the colorimetric films in fresh food packaging, we could monitor food spoilage in real-time. Additionally, we fabricated gas indicators in the form of electrospun nanofibrous membranes, which are highly porous and suitable for immediate gas detection. The nanofibrous gas indicators clearly distinguished ammonia gas concentrations ranging from 150 to 10,000 ppm.

Molybdenum doping leads to faster photo-dissolution of commercial molybdate red pigment than chrome yellow pigment under sunlight irradiation

The photo-dissolution of lead chromate pigments poses specific environmental hazards. In this study, we report that doping molybdenum in lead chromate pigments, resulting in commonly known molybdate red pigment, increases the risk of heavy metal leaching when exposed to light. Commercial molybdate red pigments undergo photo-dissolution when exposed to simulated sunlight and exhibit lower photostability compared to lead chromate pigments such as chrome yellow. After 24 h of irradiation, the leaching rates of toxic lead and chromium from molybdate red pigments were 2.98 and 3.70 times higher, respectively, than those from chrome yellow pigments. The primary factor leading to decreased pigment photostability is the activation of pigment semiconductors facilitated by molybdenum doping. Molybdate red pigments exhibit a broader light absorption spectrum and more efficient separation and transfer of photogenerated charge carriers than chrome yellow pigments, boosting the photochemical activity. To the best of our knowledge, this is the first study to illustrate the doping effect on the photostability of commercial inorganic pigments and the consequent heavy metal leaching. Our results suggest that Mo doping reduces the photostability of lead chromate pigments, highlighting the potential elevated environmental risks associated with complex inorganic pigments.

A comprehensive review on the usability of black phosphorus in energy and wastewater treatment

Increasing population and industrial development brings with it many problems that need to be solved, such as energy production, storage, saving, protection of limited reserves, and environmental pollution. Nanomaterials, which emerged with the introduction of nanotechnology into our lives, play an important role in many areas. The novel two-dimensional nanomaterial black phosphorus (BP) exhibits great potential in photocatalytic applications, energy technologies, and purification with properties such as broad light absorption spectrum, tunable direct band gap, and exceptionally high charge carrier mobility. This review gives a outline of the manufacturing techniques, structural, chemical, electrical and thermal properties of BP. Then, the success of BP derivatives with different dimensions and morphologies in environmental and energy applications is presented by comparing them with previous studies in these fields. The results show that heterojunction structures produced by combining BP with MoS2 and MOFs improve the electrochemical properties of BP, while carbonization processes increase its efficiency in battery and supercapacitor applications. Finally, in this review, a summary of BP’s potential future uses, awareness of easy production methods, and its activities in environmental and energy applications are discussed in a broad context.

Infrared optical spectra of a silicene quantum dot modulated by spin-orbit coupling and uniaxial strain

Abstract We theoretically study the electronic structure and light absorption spectra of a triangular silicene quantum dot (TZSQD) modulated by spin-orbit coupling (SOC) and the uniaxial strain from a symmetry point of view. After considering the SOC, the symmetry of the system decreases and the degenerate energy level split, creating the absorption peaks in the far infrared region and some multimodal structures in the near-infrared region and visible region. In addition, the intensity of the SOC also affects the degree of splitting of the energy levels, which makes the absorption peaks in the far infrared region are blueshifted to the mid-infrared region, and absorption edge in the near infrared region is redshifted to the mid-infrared region. We also find that when a uniaxial strain and SOC coexist at the same time, the symmetry of the system is further reduced, and the number of absorption peaks is increased. Moreover, the uniaxial strain intensity can efficiently regulate the frequency position of the absorption edge in the near-infrared region, and make its spectral range greatly expanded.

High Efficiency Removal Performance of Tetracycline by Magnetic CoFe2O4/NaBiO3 Photocatalytic Synergistic Persulfate Technology.

The widespread environmental contamination resulting from the misuse of tetracycline antibiotics (TCs) has garnered significant attention and study by scholars. Photocatalytic technology is one of the environmentally friendly advanced oxidation processes (AOPs) that can effectively solve the problem of residue of TCs in the water environment. This study involved the synthesis of the heterogeneous magnetic photocatalytic material of CoFe2O4/NaBiO3 via the solvothermal method, and it was characterized using different characterization techniques. Then, the photocatalytic system under visible light (Vis) was coupled with peroxymonosulfate (PMS) to explore the performance and mechanism of degradation of tetracycline hydrochloride (TCH) in the wastewater. The characterization results revealed that CoFe2O4/NaBiO3 effectively alleviated the agglomeration phenomenon of CoFe2O4 particles, increased the specific surface area, effectively narrowed the band gap, expanded the visible light absorption spectrum, and inhibited recombination of photogenerated electron-hole pairs. In the Vis+CoFe2O4/NaBiO3+PMS system, CoFe2O4/NaBiO3 effectively activated PMS to produce hydroxyl radicals (·OH) and sulfate radicals (SO4-). Under the conditions of a TCH concentration of 10 mg/L-1, a catalyst concentration of 1 g/L-1 and a PMS concentration of 100 mg/L-1, the degradation efficiency of TCH reached 94% after 100 min illumination. The degradation of TCH was enhanced with the increase in the CoFe2O4/NaBiO3 and PMS dosage. The solution pH and organic matter had a significant impact on TCH degradation. Notably, the TCH degradation efficiency decreased inversely with increasing values of these parameters. The quenching experiments indicated that the free radicals contributing to the Vis+CoFe2O4/NaBiO3+PMS system were ·OH followed by SO4-, hole (h+), and the superoxide radical (O2-). The main mechanism of PMS was based on the cycle of Co3+ and Co2+, as well as Fe3+ and Fe2+. The cyclic tests and characterization by XRD and FT-IR revealed that CoFe2O4/NaBiO3 had good degradation stability. The experimental findings can serve as a reference for the complete removal of antibiotics from wastewater.

A MoS2-based evaporator with porous structure and interlayer channels for solar desalination and photocatalytic degradation

The solar interfacial evaporator is a highly promising method for producing fresh water and has garnered significant attention due to its environmental friendliness and low energy consumption. MoS2, a frequently used semiconductor material for interfacial evaporation, has been the focus of research aimed at enhancing evaporation rate and efficiency, with less consideration given to its salt resistance and other potential capabilities. In this work, we introduce a novel ANF/MoS2@MXene evaporator that employs vertically aligned MoS2 nanosheets coated on MXene as the photothermal material and aramid nanofiber aerogel (ANF) as the substrate. The evaporator exhibits both photothermal and photocatalytic degradation effects. The existence of MXene and vertically oriented MoS2 nanosheets contributes to a broad light absorption spectrum, resulting in an evaporation rate of 1.42 kg m-2h−1 and an efficiency of 95.84 % under one sun. Additionally, the porous structure and interlayer channels within the ANF facilitate rapid water transfer and timely salt discharge. This leads to a stable evaporation rate of 1.28–1.37 kg m-2h−1, preventing salt crystal accumulation on the evaporator’s surface during 10 h of continuous operation in 3.5 % NaCl solution. The evaporator also demonstrated an effective degradation rate of 89.24 % in treating dye wastewater after 2-hour light exposure. This work presents a promising approach for constructing a photothermal evaporation/photocatalytic bifunctional system with enhanced salt resistance for MoS2-based evaporators.

Tuning oxygen vacancies via photoinduced defect engineering in plasma pre-treated TiO2 for efficient solar-light-driven oxidation of trace methane

Photocatalysis employing cost-effective commercial titanium dioxide offers an ideal solution for eliminating trace methane emissions from livestock and poultry farming. However, significant challenges such as the rapid recombination of photogenerated carriers, a limited light absorption spectrum, and weak adsorption capabilities considerably hinder the effectiveness of titanium dioxide in the photocatalytic treatment of trace methane. This study proposes a novel approach to activate plasma pre-treated N-doped commercial anatase TiO2 into dual-defect TiO2 (N-doped TiO2-x) featuring stable and controllable oxygen vacancies (OV) through photoinduced defect engineering. Characterizations of the photocatalyst confirm the successful creation of surface defects, further evaluated through solar-light-driven CH4 (ppm level) removal investigations. The yield of this N-doped TiO2-x in converting CH4 is 4.84 μmol h−1, 44 times greater than that of unmodified TiO2, significantly outperforming previous studies. UV–Vis diffuse reflection spectra, and photoluminescence indicate that the modified commercial anatase TiO2 possesses a narrower band gap, efficient photogenerated carrier separation, and enhanced charge transfer. Furthermore, density functional theory (DFT) calculations demonstrate that the synergistic effects of oxygen vacancies and N doping enhance the adsorption and activation of both O2 and CH4 in the rate-determining step of the reaction. This innovative strategy holds considerable promise for modifying various materials for more efficient photocatalytic applications.

Mitigating UV-Induced Degradation in Solar Panels through ZnO Nanocomposite Coatings

This study explores the enhancement of silicon-based solar cell performance and durability through the application of zinc oxide (ZnO) nanocomposite film coatings. Utilizing the sol–gel method, ZnO nanorods were synthesized and dispersed within a polyvinyl butyral (PVB) matrix, resulting in uniform nanocomposite films. Comprehensive characterization using X-ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), UV-Visible spectroscopy, and contact angle measurements confirmed the effective integration and desirable properties of ZnO within the PVB matrix. The ZnO coatings demonstrated superior UV absorptivity, significantly blocking UV radiation at 355 nm while maintaining high transparency in the visible range. This led to improvements in key photovoltaic parameters, including short circuit current (Jsc), open-circuit voltage (Voc), efficiency (η), and fill factor (FF). Although a minor reduction in Isc was observed due to the ZnO layer’s influence on the light absorption spectrum, the overall efficiency and fill factor experienced notable enhancements. Furthermore, the thermal load on the solar cells was effectively reduced, mitigating UV-induced degradation and thereby prolonging the operational lifespan of the solar panels. Under damp heat conditions, the coated solar panels exhibited remarkable durability compared to their uncoated counterparts, underscoring the protective advantages of ZnO films. These findings highlight the potential of ZnO nanocomposite coatings to significantly boost the efficiency, reliability, and longevity of silicon-based solar panels, making them more viable for long-term deployment in diverse environmental conditions.

Cyanoacetamide co-sensitizers DY-1 and DY-2: Unveiling a promising path to highly efficient photovoltaic devices

This paper presents a novel approach for enhancing the efficiency of dye-sensitized solar cells (DSSCs) through the co-sensitization of cyanoacetamide-based dyes DY-1 and DY-2 with N3 dye. The synthesis and characterization of DY-1 and DY-2 co-sensitizers are described and their potential applications in photovoltaic devices are investigated. The absorption properties of DY-1 and DY-2 were analyzed, revealing their efficient light absorption in the visible range. The co-sensitization of DY-1-2 with N3 dye demonstrated a significant enhancement in photovoltaic efficiency, ranging from 7.40 % to 7.92 %. The reasons for this efficiency enhancement were thoroughly analyzed and attributed to several factors. First, the combination of DY-1-2 with the N3 dye led to a broader light absorption spectrum, enabling more efficient utilization of incident photons. Additionally, co-sensitization facilitates efficient charge separation and injection processes, contributing to improved photocurrent. The acid-base co-sensitization approach further enhances the overall efficiency by maximizing the charge transfer and coverage on the semiconductor surface. This study sheds light on the development of novel sensitizers to enhance the performance of DSSCs, and the findings contribute to the advancement of photovoltaic devices.

Piezoelectric, Thermoelectric, and Photocatalytic Water Splitting Properties of Janus Arsenic Chalcohalide Monolayers.

In this study, we systematically investigate the piezoelectric, thermoelectric, and photocatalytic properties of novel two-dimensional Janus arsenic chalcohalide monolayers, AsXX' (X = S and Se and X' = Cl, Br, and I) using density functional theory. The positive phonon spectra and ab initio molecular dynamics simulation plots indicate these monolayers to be dynamically and thermally stable. The mechanical stability of these monolayers is confirmed by a nonzero elastic constant (C ij ), Young's modulus (Y 2D), and Poisson ratio (ν). These monolayers exhibit strong out-of-plane piezoelectric coefficients, making them candidate materials for piezoelectric devices. Our calculated results indicate that these monolayers have a low lattice thermal conductivity (κl) and high thermoelectric figure of merit (zT) up to 1.51 at 800 K. These monolayers have an indirect bandgap, high carrier mobility, and strong visible light absorption spectra. Furthermore, the AsSCl, AsSBr, and AsSeI monolayers exhibit appropriate band alignment for water splitting. The calculated value of the corrected solar-to-hydrogen conversion efficiency can reach up to 19%. The nonadiabatic molecular dynamics simulations reveal the prolonged electron-hole recombination rates of 1.52 0.98, and 0.67 ns for AsSCl, AsSBr, and AsSeI monolayers, respectively. Our findings demonstrate these monolayers to be potential candidates in energy-harvesting fields.