Band Gap Research Articles

High-Temperature Molecular Ferroelectric [C4N2H14]2[Sb2I10] with Narrow Bandgap and Switchable Photoelectric Response.

Organic-inorganic hybrid ferroelectrics have attracted considerable attention due to their outstanding piezoelectricity, mechanical flexibility, and robust nonlinear optical properties. But the species with above room-temperature (RT) ferroelectricity, visible-light bandgap, and high photoelectric performance are still scarce. Herein, a novel organic-inorganic hybrid ferroelectric [C4N2H14]2[Sb2I10] has been synthesized hydrothermally and employed as a light-absorbing layer in organic-inorganic hybrid solar cells. A polar monoclinic structure with a space group of Pn was resolved by single-crystal XRD. A direct band gap of 1.89 eV was revealed in [C4N2H14]2[Sb2I10] by UV-vis spectroscopy and density functional theory (DFT) studies. A dramatic enhancement in photoelectric performance has been achieved by turning the ferroelectric polarization, leading to a maximum Voc ∼ 0.52 V and Jsc ∼ 15.52 μA/cm2, which are 15-fold and 29-fold higher than those of the unpoled sample, respectively. This work may open new avenues for the application of molecular ferroelectrics in optoelectronic devices.

Iron-irradiated methylammonium lead iodide bromide (MAPbI2Br) thin films with enhanced optical and electrical properties for high-efficiency perovskite solar cells

In the pursuit of enhancing the optoelectronic properties of perovskite thin films for photovoltaic applications, this study investigates the effects of Fe ion irradiation on methylammonium lead iodide bromide (MAPbI₂Br) thin films. Thin films of methylammonium lead iodide bromide, (CH3NH3PbI2Br, or MAPbI2Br) have been deposited by sol–gel dip coating technique. These films were irradiated with 300 keV Fe ions with flouncy of 2 × 1014 ions/cm2. The prepared films all show the cubic crystal structure. However, the film irradiated with Fe ions has a larger grain size, according to XRD. The optical characteristics, such as refractive index, band gap energy, and extinction coefficients, are examined by UV–Vis analysis. Although both the films showed a direct bandgap, the film irradiated with Fe ions showed a lower value for the bandgap energy (1.76 eV) and high refractive index. The device structure used was FTO/TiO2/MAPbI2Br/spiro-OMeTAD/Au. The devices made with 300 keV Fe ions irradiated film has high current density of 10.86 mA cm−2, fill factor of 0.80, an open circuit voltage of 1.06 V, and an efficiency of 9.93%. The findings emphasize the potential of Fe ion irradiation as a novel technique to improve grain structure and optoelectronic properties, advancing perovskite-based device technology for higher efficiency solar cells.

Intrinsic defects in α-Al2O3: structural and electronic properties

Abstract Due to their high dielectric constants and wide band gaps, Al 2 O 3 has become popular in semiconductor applications, but with high-density interface defect structures. Understanding the structural distortions of intrinsic defects and their impact on electronic properties, is of particular importance for the applications. Herein, we study the impacts of four intrinsic defects on the structural and electronic properties of α- Al 2 O 3 using first-principles calculations. The four intrinsic defects cause structural distortions at their respective defect sites and defect states within the band gap, with O i inducing the most significant distortions and exhibiting the most complex defect states accordingly. When the Fermi level is 3.05 eV under O-poor conditions, VO is the most favorable defects based on the formation energy calculations. Additionally, the intrinsic defects in α- Al 2 O 3 can effectively modulate band edges, and thus modify the leakage currents. In summary, our results provide significant theoretical insights for α- Al 2 O 3 -based semiconductor applications.

High pressure induced superconductivity and chirality-neutral Fermi surface in SrSi2

In this study, we investigate the electronic structure and topological properties of the compound SrSi2 using angle-resolved photoemission spectroscopy (ARPES), electrical transport measurements, and calculations. In contrast to recent theoretical predictions that SrSi2 is a Weyl semimetal with robust Weyl nodes and Fermi arcs, our ARPES measurements on undoped and Ca-doped SrSi2 single crystals show no evidence of the predicted Weyl fermions or Fermi arcs at ambient pressure. Instead, ARPES and transport data show that SrSi2 is a narrow-gap semiconductor at ambient conditions. Our hybrid functional calculations also find a small band gap, in agreement with experiments. However, by applying external pressure, we induce a topological phase transition where the electronic bands overlap and Weyl nodes appear, as confirmed by transport measurements and calculations. Interestingly, we also observe a pressure-induced superconducting transition above 20 GPa. Our results establish SrSi2 as a platform to study the interplay between topological states and superconductivity driven by external pressure. Importantly, our results challenge the previously predicted intrinsic Weyl semimetallic nature of SrSi2 and highlight the need for combined experimental and advanced computational approaches to correctly describe the complex electronic structures in topological materials. Published by the American Physical Society 2024

Tuning optical and electronic properties of indanthrene derivatives with electron-withdrawing groups (-Cl, -NO₂ and -C≡N) for enhanced organic solar cell performance: a DFT approach

Abstract In this study, we focused on improving the electronic and optical properties of the reference compound indanthrene (R) by introducing electron-withdrawing groups (−Cl, −C≡N, −NO₂). density functional theory and time-dependent density functional theory calculations were performed using Gaussian 16 software to study indanthrene derivatives as electron acceptor materials. The electronic and optical properties of the designed molecules (M1-M8) were investigated through frontier molecular orbital analysis, UV-visible absorption spectra, density of states, and transition density matrix analysis, utilizing GaussView 6.0 and Multiwfn 3.8 software. The designed molecules exhibit absorption across the entire visible spectrum, with maxima extending up to ~737 nm. Their electron affinity values range from 3.0 to 4.0 eV, surpassing the fullerene-based acceptor material. Among the designed molecules, M5 stands out with superior photovoltaic parameters, including a narrow optical band gap (~1.68 eV), exciton binding energy (0.25 eV), higher electron affinity (3.35 eV), an extended excited state lifetime (17.0 ns) owing to its low electron and hole reorganization energies (λe ~ 0.190 eV, and λh ~ 0.134 eV), and improved short-circuit current density of ~ 15.7 mA/cm². The photovoltaic parameters and power conversion efficiency were assessed using the Scharber and Alharbi models. The calculated device parameters, including light harvesting energy and photovoltaic characteristics (Voc, FF, Jsc, and PCE), suggest that these molecules, with electron-withdrawing groups, show great potential for use as acceptors in organic solar cells, particularly in terms of stability and power conversion efficiency. Notably, M2 and M5, with their PCE values exceeding 16%, emerge as outstanding candidates for device performance, impressively outperforming the other designed molecules.

Studies on Synthesis, Physical and Optical Properties of Dysprosium Ion-Doped Transparent Heavy Metal Oxide Glasses

The melt quench method was used to synthesize Dysprosium ions doped heavy metal oxide glasses of composition 50%TeO2–(30-x)%B2O3-10%Bi2O3–10%Na2O–x%Dy2O3(mol%) (x= 0, 0.2, 0.4, 0.6 and 0.8). The proof of glassy nature of prepared samples is substantiated by the X-ray diffractogram (XRD). Differential scanning calorimetry (DSC) is carried to obtain the value of glass transition temperature (Tg). Physical parameters such as polaron radius, density, inter-ions distance, lanthanide ion concentration and oxygen packing density (OPD) were calculated. Tauc’s plot is drawn to get information of energy band gap and hence refractive index. The distinctive absorption bands of dysprosium ions exist at 320, 348, 365, 387, 794, and 882 nm. The energy transitions from the 6H15/2 level to various higher levels of dysprosium ions are responsible for the UV-VIS-NIR absorption spectra. Using emissions monitoring at 576 nm, the excitation spectra was obtained between 200 and 550 nm. The 6H15/2→4I13/2, 4G11/2, 4I15/2, and 4F9/2 transitions were identified as the sources of the excitation bands at 390, 426, 452 and 470 nm, respectively. Notable bands of emission were observed when stimulated at 447 nm for 485, 575, 662, and 756 nm wavelengths it is due to the energy transfer from 4F9/2→6H15/2, 4F9/2→6H13/2, 4F9/2→6H11/2, and 4F9/2→6H9/2, 6F11/2. It was found the light emission from the samples was white.

Energy Transfer Studies on Red Emitting CaGdSbWO8: Sm3+/Eu3+ Phosphor for w-LEDs and Indoor Plant Growth Lighting System.

In the present research work, a solid-state reaction method was employed to synthesize a series of CaGd(0.95-x)SbWO8:Sm0.05Eux (x = 1, 1.5, 2, 3 and 4mol%) phosphors. The phase purity, crystallinity, morphological and compositional studies were analysed via X-ray diffraction (XRD), scanning electron microscopy (SEM) imaging, and energy dispersive spectroscopy (EDS) analysis. The Fourier transform infrared (FT-IR) spectroscopy was utilized to measure OH content in the prepared phosphor material. The diffused reflectance spectroscopy (DRS) analysis was applied to measure the optical energy band gap. The photoluminescence (PL) spectroscopy at excitation wavelengths 275 and 405nm was carried out to analyze the luminescence properties of the prepared phosphors. The intensity of emission peaks of Sm3+ ions decreased as the concentration of Eu3+ ions increased showing the energy transfer mechanism from Sm3+ to Eu3+ ions. The dipole-dipole interaction mechanism is responsible for the energy transfer between Sm3+ to Eu3+ ions as assessed using the Reisfeld approximation. The CIE coordinates of the prepared samples lie in the warm red region represented by the relatively low (3200K) value of correlated color temperature. These results show the suitability of the prepared phosphor for white light emitting diode (w-LEDs) and also in indoor plant growth lighting systems.

Self-assembly of ZnO-Biochar/Kaolinite/Chitosan/GO with 1D/2D/3D heterojunctions for enhanced removal of estrogens and triclosan in water

This Study focuses on the preparation of sustainable and efficient Chitosan catalyst for the removal of three organic pollutants, 17β-Estradiol (E2), 17α-ethynyl estradiol (EE2) and triclosan (TCS) from water. The prepared nanocomposites were characterized by different techniques which confirmed the presence of the key components Chitosan, Carica Papaya seed and Kaolinite. The optical characterization proved the nanocomposite is photoactive with a band gap of 1.81 eV and 1.77 eV for Chitosan/kaolinite biochar (CS/KBC) and Chitosan/kaolinite biochar/GO (CS/KBC/GO) respectively, confirming the ability of the nanocomposite to be active in the visible light region of the spectrum. The degradation experiment using CS/KBC/GO was observed better with 100% removal for 5 mg/L E2 and EE2 over 60 min and 97.8% over 120 min for 10 mg/L TCS at optimum conditions (pH 3 for E2, and EE2 and pH 7). It was observed that the superoxide radical played a major role in the degradation of the contaminants. Furthermore, the CS/KBC/GO was efficient over four cycles without any decrease in performance, which rules out the question of catalyst deactivation proving the sustainability of the catalyst. The toxicity test shows that the water is safe as it does not harm cerio daphnia silvestrii organism.; CS/KBC/GO efficiently removed the micropollutants from real-life waste samples and the performance was very good with a slight decrease in performance for the wastewater due to the complex matrix of the water sample that competes for the active site.

Synthesis, Characterization, and Optical Properties of NiCr2O4 and CoCr2O4 Spinel Nanostructures for Photocatalytic Applications

This study focuses on the synthesis and characterization of two cubic spinel oxides, NiCr2O4 and CoCr2O4, utilizing X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, and UV-Visible (UV-Vis) spectroscopy. The investigation aimed to explore their structural and optical properties for potential applications in advanced technologies such as catalysis, sensors, and optoelectronics. XRD analysis confirmed that both NiCr2O4 and CoCr2O4 crystallize in the cubic spinel structure with the space group Fd-3m. The lattice parameters, 8.307 Å for NiCr2O4 and 8.285 Å for CoCr2O4, reveal slight variations attributed to the differing ionic radii of Ni2+ and Co2+, with both compounds exhibiting high crystallinity. FT-IR spectroscopy confirmed the presence of metal-oxygen bonding characteristic of spinel structures. In NiCr2O4, the Ni-O and Cr-O stretching vibrations were identified at 681 cm⁻1 and 485 cm⁻1, respectively, while CoCr2O4 exhibited similar vibrations at 570 cm⁻1 and 485 cm⁻1. UV-Vis spectroscopy demonstrated significant optical absorption in the UV and visible regions. NiCr2O4 displayed absorption peaks at 237 nm, 295 nm, 406 nm, and 580 nm, whereas CoCr2O4 exhibited peaks at 247 nm, 295 nm, 411 nm, and 574 nm. Analysis using Tauc plots determined optical band gaps of 2.969 eV for NiCr2O4 and 2.015 eV for CoCr2O4, confirming their semiconducting nature and suitability for visible-light-driven applications.

Even harmonic generation in semiconductors below and above the band gap assisted by an intense terahertz field

Even harmonic generation in semiconductors below and above the band gap assisted by an intense terahertz field

Correlation of Band Bending and Ionic Losses in 1.68 eV Wide Band Gap Perovskite Solar Cells

AbstractPerovskite solar cells (PSCs) are promising for high‐efficiency tandem applications, but their long‐term stability, particularly due to ion migration, remains a challenge. Despite progress in stabilizing PSCs, they still fall short compared to mature technologies like silicon. This study explores how different piperazinium salt treatments using iodide, chloride, tosylate, and bistriflimide anions affect the energetics, carrier dynamics, and stability of 1.68 eV bandgap PSCs. Chloride‐based treatments achieved the highest power conversion efficiency (21.5%) and open‐circuit voltage (1.28 V), correlating with stronger band bending and n‐type character at the surface. At the same time, they showed reduced long‐term stability due to increased ionic losses. Tosylate‐treated devices offered the best balance, retaining 96.4% efficiency after 1000 h (ISOS‐LC‐1I). These findings suggest that targeted surface treatments can enhance both efficiency and stability in PSCs.

Thermodynamic Optoelectronic and Photovoltaic Properties of Al-doped Boron Arsenide alloy

Abstract This study investigates the electronic, optical, thermoelectric, and thermodynamic properties of BAs using Density Functional (DFT) and Semi-Classical Boltzmann theories. The band gap, initially determined by the GGA approximation, is refined using the TB-mBJ method, HSE, SOC and GGA+U inelectronic property. Our calculations show a significant reduction in the band gap closed by the various approaches when aluminum (Al) is introduced into the BAs lattice, extending the material`s light absorption spectrum into the visible range. The thermoelectric properties of both pure and Al-doped BAs are evaluated near the Fermi level at various temperatures. The positive Seebeck coefficient indicates p-type behavior, and Al incorporation enhances electrical conductivity. The mechanical properties indicate that the compounds are stable. These findings denote potential applications for Al-doped BAs in thermoelectric and optoelectronic devices.

Platinum Compound on Gold–Magnesia Hybrid Structure: A Theoretical Investigation on Adsorption, Hydrolysis, and Interaction with DNA Purine Bases

Cisplatin-based platinum compounds are important clinical chemotherapeutic agents that participate in most tumor chemotherapy regimens. Through density-functional theory calculations, the formation and stability of the inorganic oxide carrier, the mechanisms of the hydrolysis reaction of the activated platinum compound, and its binding mechanism with DNA bases can be studied. The higher the oxidation state of Pt (II to IV), the more electrons transfer from the magnesia–gold composite material to the platinum compound. After adsorption on the composite carrier, 5d←2p coordination bonds of Pt-N are strengthened. For flat and oblique adsorption modes of cisplatin, there is no significant difference in the density of states of the gold and magnesium oxide film, indicating the maintenance of the heterojunction structural framework. However, there are significant changes in the electronic states of cisplatin itself with different adsorption configurations. In the flat configuration, the band gap width of cisplatin is larger than that of the oblique configuration. The Cl-Pt bond range in the Pt(III) compound shows a clear charge reduction on the magnesia film, indicating the Cl-Pt bond is an active site with the potential for decomposition and hydrolysis. The substitution of chloride ions by water can lead to hydrolysis products, enhancing the polarization of the composite and showing strong charge separation. The hydrolysis of the free platinum compound is endothermic by 0.309 eV, exceeding the small activation energy barrier of 0.399 eV, indicating that hydrolysis of this platinum compound is easily achievable. ADME (absorption, distribution, metabolism, and excretion) prediction parameters indicate that hydrolysis products have good ESOL (Estimated SOLubility) solubility and high gastrointestinal absorption, consistent with Lipinski’s rule. During the coordination reaction process, there are significant changes in the distribution of frontier molecular orbitals, with the HOMO (highest occupied molecular orbital) of the initial state primarily located on the purine base, providing the possibility for electron transfer to the empty orbitals of the platinum compound in the LUMO (lowest unoccupied molecular orbital). The HOMO and HOMO-1 of the transition state and product are mainly distributed on the platinum compound, indicating clear electron transfer and orbital rearrangement. The activation energy barrier for the purine coordination reaction with the hydrolysis products is reduced to 0.61 eV, and the dipole moment gradually decreases to 6.77 Debye during the reaction, indicating a reduction in the system’s charge separation and polarization. This contribution is anticipated to provide a new theoretical clue for developing inorganic oxide carriers of platinum compounds.

DFT investigation on thermoelectric, electronic, optoelectronic, elastic, and structural properties of sodium‐based halide double perovskites Rb2NaSbZ6 (Z = Cl, Br, and I)

AbstractSodium‐based halide double perovskites (HDPs) present a promising alternative to Pb‐based perovskites for safe solar and thermal energy conversion devices due to their high durability and non‐toxic elements. This study examines the electronic, thermoelectric, elastic, optoelectronic, and structural properties of Rb2NaSbZ6 (Z = I, Br, Cl) double perovskite compounds using density functional theory (DFT). These compounds, characterized by a cubic structure, show increasing structural parameters as halogens are substituted from chlorine to iodine. Structural stability is confirmed by evaluating the enthalpy of formation, Gibbs free energy, Born and Huang criteria, and tolerance factor. Pugh's ratio indicates the ductile nature of the compounds. All investigated halide compounds exhibit an indirect band gap ranging from 3.9 to 2.34 eV, with valence and conduction band extrema located at different symmetry points, and a higher effective mass of holes is noted. This study also analyzes the refractive index, optical loss, light absorption, and polarization across the energy range of 0–10 eV. The spectral characteristics indicate that these HDPs are suitable for optoelectronic and photovoltaic devices due to their absorption in the visible and near‐ultraviolet spectra. High figures of merit (0.45–0.6) derived from power factor and thermal conductivity calculations suggest the potential of these compositions as thermoelectric devices. These findings provide a comprehensive understanding of these materials, facilitating their further deployment.

Influence of strain and point defects on the electronic structure and related properties of (111)NiO epitaxial films

Abstract (111)NiO epitaxial films are grown on c-sapphire substrates at various growth temperatures ranging from room temperature to 600 ∘ C using pulsed laser deposition technique. Two series of samples, where different laser fluences are used to ablate the target, are studied here. Films grown with higher laser fluence, are found to be embedded with Ni-clusters crystallographically aligned with the (111)NiO matrix. While the layers grown with lower laser energy density exhibit p-type conductivity, especially at low growth temperatures. X-ray diffraction study shows the coexistence of biaxial compressive and tensile hydrostatic strains in these samples, which results in an expansion of the lattice primarily along the growth direction. This effective uniaxial expansion ε ⊥ increases with the reduction of the growth temperature. Band gap of these samples is found to decrease linearly with ε ⊥ . This result is validated by density functional theory calculations. Experimental findings and the theoretical study further indicate that V Ni + O I and V O + N i I complexes exist as the dominant native defects in samples grown with Ni-deficient (low laser fluence) and Ni-rich (high laser fluence) conditions, respectively. P-type conductivity observed in the samples grown in Ni-deficient conditions is more likely to result from V Ni + O I defects than Ni-vacancies ( V Ni ).

ReLMM: Reinforcement Learning Optimizes Feature Selection in Modeling Materials.

A challenge to materials discovery is the identification of the physical features that are most correlated to a given target material property without redundancy. Such variables necessarily comprise the optimal search domain in subsequent material design. Here, we introduce a reinforcement learning-based material model (ReLMM) as a tool for analyzing a given database in identifying a minimal or near minimal subset of physical features for the design of a material with a given target property. We aim for minimality in the selected subset with respect to its size─smaller being better─ while maintaining the desired accuracy of the prediction. We have shown, using synthetic multiscale data sets, that ReLMM can identify the relative importance of features, and thus help identify which should be selected across scales. In the context of semiconducting materials, ReLMM can be used to improve the prediction of the band gap by identifying which features should be selected in model building. For metal halide perovskites, ReLMM was seen to find a near minimal data set at least as well as, if not better than, state-of-the-art feature selection tools such as LASSO and XGBoost. We also found that our domain-science oriented approach can be used to uncover the hierarchical structure of a material from a database consisting of molecular-scale, mesoscale and device-scale features and labels in complementarity with an earlier hierarchical model called NestedAE.

Theoretical Study of Exciton Properties of Dilute Gainasn Semiconductors

In this research, the electronic band structure, electronic properties and the exciton binding energy of dilute quaternary GaInAsN alloy semiconductors are investigated. This study was aimed to theoretically study the exciton properties of dilute GaInAsN semiconductors. The effects of Nitrogen incorporation in InGaAs alloy was studied within the band anti-crossing model (BAC). The pseudopotential inputs within the virtual crystal approximation (VCA) was employed to make modifications for the nitrogen and indium related alloy disorder effects. The Harrison’s model used to study the bandstructure. In general, the results of our computations are in agreement with recent experimental findings. It is found that the presence of nitrogen in the GaInAsN alloy reduces the fundamental bandgap energy within the band anticrossing (BAC) model in the vicinity of the first Brillouin zone boundary, to . The heavy hole and electron effective masses, reduced mass, energy band gap, high frequency dielectric constant, static dielectric constant, the refractive indices, polarity, covalency, Bohr radius and binding energy are also modified by the nitrogen and indium fractions of the alloy. For all the alloy compositions studied, it was observed that the binding energies of the excitons vary between the values for InAs and GaAs . Also, the corresponding excitons Bohr radii vary between the values for InAs and GaAs . The information derived from the present study predicts that GaInAsN tunable binding energies and electronic properties are of great technological importance for mid-infrared (MIR) optoelectronics.

Exploring the physicochemical properties and antifungal activity of zinc oxide nanoparticles

ABSTRACT In this study, zinc oxide nanoparticles were synthesized using the chemical precipitation method with zinc acetate dihydrate and sodium hydroxide as precursors. UV-Vis spectroscopy confirmed the formation of ZnONPs, showing a characteristic absorption peak at around 360–370 nm, corresponding to a band gap energy of approximately 3.2 eV. XRD analysis indicated the crystalline nature of ZnONPs with a hexagonal wurtzite structure. FTIR and EDS analyses confirmed the presence of ZnONPs in the component. TEM revealed nearly spherical ZnONPs with average particle sizes of 26.1 nm for bare ZnONPs and 24.6 nm for PVP-capped ZnONPs. BET measurements showed a higher specific surface area for PVP-capped ZnONPs. The antifungal efficacy of ZnONPs was tested against Phytophthora capsici at concentrations ranging from 20 to 100 ppm. Results demonstrated significant inhibition of fungal growth, especially with PVP-capped ZnONPs, with complete inhibition at concentrations ≥60 ppm after 12 to 48 hours of incubation.

UNTANGLING THE VALLEY STRUCTURE OF STATES FOR INTRAVALLEY EXCHANGE ANISOTROPY IN LEAD CHALCOGENIDES QUANTUM DOTS

We put forward a generalized procedure which allows to restore the bulk-like electron and hole wave functions localized in certain valleys from the wave functions of quantum confined electron/hole states obtained in atomistic calculations of nanostructures. The procedure is applied to the lead chalcogenide quantum dots to accurately extract the intravalley velocity matrix elements and the constants of the effective intravalley Hamiltonian of the exchange interaction for the ground exciton state in PbS and PbSe quantum dots. Our results suggest that intravalley parameters in PbS quantum dots are much more anisotropic than the ones in PbSe. Renormalization of the velocity matrix elements, forbidden band gap, valley and exchange splittings of exciton and exciton binding energy are also calculated.

Effective removal of atrazine pesticide residue from wastewater using transition metal-doped zinc oxide photocatalyst

Frequent use of pesticides results in the release of large quantities of their residues in the environment, raising various concerns for humans and the ecosystem. This work introduces a simple and cost-effective method for removal atrazine pesticide residue (APR) from agricultural wastewater using Cu doped-ZnO photocatalyst (Cu-ZnO). The modification of ZnO with Cu significantly improved its optical and photoelectrochemical properties, with the band gap narrowing from 3.3 to 2.64 eV. The photodegradation of APR was 93.6 and 91.7% in aqueous solution and agricultural wastewater, respectively. After being reused four times, Cu-ZnO did not display a notable drop in degradation performance, with the rates of 93.6, 91.2, 86.8, and 83.1% during the first, second, third, and fourth recycles, respectively. Also, the release of Cu from Cu-ZnO after six cycles was <2%, suggesting the excellent stability of the modified photocatalyst without any issues related to secondary pollution. Under natural sunlight, 83.9% of APR was removed, confirming the benefit of Cu-ZnO in reducing the treatment costs of pesticides by utilizing renewable energy. In addition, the degradation mechanism of APR by Cu-ZnO was proposed based on the outcomes of radical quenching and TOC removal tests.