Localized Surface Plasmon Research Articles

Directional picoantenna behavior of tunnel junctions formed by an atomic-scale surface defect.

Plasmonic nanoantennas have attracted much attention lately, among other reasons because of the directionality of light emitted by fluorophores coupled to their localized surface plasmon resonances. Plasmonic picocavities, i.e., cavities with mode volumes below 1 nm3, could act as enhanced antennas due to their extreme field confinement, but the directionality on their emission is difficult to control. In this work, we show that the plasmonic picocavity formed between the tip of a scanning tunneling microscope and a metal surface with a monoatomic step shows directional emission profiles and, thus, can be considered as a realization of a picoantenna. Electromagnetic calculations demonstrate that the observed directionality arises from the reshaping and tilting of the surface charges induced at the scanning tip due to the atomic step. Our results pave the way to exploiting picoantennas as an efficient way for the far-field probing and control of light-matter interactions below the nanoscale.

Localized surface plasmon resonance of a Cu nanodot array covered with a native oxidation layer

Localized surface plasmon resonance of a Cu nanodot array covered with a native oxidation layer

Investigation of dependent scattering criterion for dispersed particulate medium: Effects of metal particle plasmon resonances and host medium absorption

Spectral radiative transfer between particles within dispersed particulate medium is prevalent across various fields, which may be influenced by the microscopic dependent scattering effect (DSE). However, independent scattering assumption (ISA) is only employed in the radiative transfer of most studies, which can lead to significant errors. Consequently, there is an urgent need to establish the more accurate and widely applicable dependent scattering criterion for determining whether the radiative transfer is independent or dependent scattering. However, the most existing criteria are only applicable under the assumption of optically soft particles with weak absorption. This limitation results in the criteria being valid only for certain types of particles, excluding nonmetal particles with highly complex refractive indices and metal particles with strongly absorption. Furthermore, the existing criteria also fail to consider the impact of host medium absorption (HMA) on the localized surface plasmon resonance (LSPR) of metal particles and the DSE between particles. It would represent another significant limitation. To address these above limitations, this paper develops a comprehensive and systematic dependent scattering criterion with considering the plasmon resonances for metal particle and host medium absorption. The multiple sphere T-matrix (MSTM) method, generalized Mie scattering, and Monte Carlo ray tracing (MCRT) method are further employed to calculate and compare the radiative properties across different scales. The extinction cross section is the most suitable contrast parameter in the dependent scattering criterion with the consideration of host medium absorption. Clearance-to-wavelength ratio c/λ is used to characterize dependent scattering criterion. Consequently, the dependent scattering criterion c/λ for nonmetal particles is 6. While the dependent scattering criterion c/λ for metal particles is 5.5.

Dynamically Tunable Localized Surface Plasmon Resonance in Self‐Assembled SrCoOx‐Au Vertically Aligned Nanocomposite Thin Films

AbstractWhile the physical principles for regulating localized surface plasmon resonance (LSPR) are well established, dynamically tuning the LSPR in a given material post synthesis remains challenging. Herein, this study demonstrates a strategy for dynamically tuning the LSPR of Au nanostructures by selectively altering the dielectric environment. Au is integrated with an electrochemically gatable oxide, i.e., SrCoOx (SCO), into vertically aligned nanocomposite thin films via a self‐assembly growth mechanism, where Au develops into nanopillars embedded in the SCO matrix. By selectively controlling the tri‐state phase transitions of SCO matrix via varying the bias voltage polarity in ionic liquid gating (ILG), the LSPR behavior of Au nanopillars can be dynamically tuned. Specifically, gating with a negative bias fully suppresses the LSPR, while a positive bias leads to a continuous blueshift of the LSPR wavelength upon increasing the ILG duration. This work not only opens new directions for the dynamic control of LSPR of noble metal nanostructures, but also offers insight to the voltage control of multifunctionalities via structural and physical intercoupling between different phases in self‐assembled nanocomposites.

Construction of aptamers-modified plasmonic GO/urchin-like Au nanoparticles with enhanced photothermal performance and their efficient capture and elimination of Staphylococcus aureus

Here, aptamers-modified graphene oxide/urchin-like Au nanoparticles (Apt-GUANPs) were developed for efficient capture and photothermal therapy (PTT) of Staphylococcus aureus (S. aureus). Specifically, anisotropic UANPs were first prepared, and the excellent photothermal property was related to the localized surface plasmon resonance (LSPR) in the near infrared (NIR) region caused by sharp branching. Then GO, which was used to enhance the photothermal effect, was added and assembled into GUANPs by electrostatic action. Infrared images showed that GUANPs exhibited a stronger photothermal effect than UANPs. Under the irradiation of 808 nm laser, the photothermal conversion efficiency (η) of GUANPs was as high as 40.5 %, which was attributed to the enhanced optical response of GUANPs at 808 nm and the strong plasmonic coupling effect between tightly packed UANPs loaded on GO surfaces. Aptamers were modified on the surfaces of GUANPs for specific capture of S. aureus, with the capture efficiency of up to 72 %. Utilizing the specific capture ability of aptamers and the excellent photothermal property of GUANPs, Apt-GUANPs exhibited the strong photothermal killing ability against S. aureus. Therefore, Apt-GUANPs will be a promising and efficient photothermal agent, and will have a great application prospect in the treatment of bacterial infections in the future.

Seed‐Mediated Synthesis of Gold Nanobipyramids at Low CTAB Concentration Using Binary Surfactants

AbstractThe conventional method for synthesizing gold nanobipyramids (AuNBPs) is well established. However, the cytotoxicity resulting from the conjugates between hexadecyltrimethylammonium bromide (CTAB) and gold limits their biomedical applications. This study introduces a dual surfactant approach with CTAB and sodium oleate (NaOL) in the seed‐mediated synthesis of the AuNBPs, which can significantly reduce the CTAB concentration to 10 mM. Additionally, optimal growth conditions are achieved by varying the volumes of seed solution, AgNO3, and HCl. Under low CTAB concentrations, AuNBPs with tunable sizes and localized surface plasmon resonances between 600 and 1200 nm are successfully synthesized, as characterized by UV–vis‐NIR spectroscopy, transmission electron microscopy (TEM), and finite‐difference time‐domain (FDTD) simulations. This work demonstrates a method for synthesizing AuNBPs at low CTAB concentrations using binary surfactants and provides a framework applicable to the synthesis of other metallic nanomaterials.

Femtosecond laser-induced black silicon: a dual application in photodetection and surface-enhanced Raman scattering

A multifunctional structured silicon with enhanced optical and photoelectric properties has been processed by femtosecond (fs) laser in ambient air. The structured surface decorated with Au nanoparticles (NPs) exhibits excellent infrared absorption properties related to localized surface plasmon resonance (LSPR) coupled to microstructures. Over 75% absorption is achieved at 1550 nm, which is three orders of magnitude higher than that of unprocessed Si. The absorption enhancement results in increased photocurrent response in n + -n junction diodes, exhibiting a responsivity of 125 mA/W and an external quantum efficiency (EQE) of 10% at 1550 nm, for a bias voltage of 10 V. Moreover, the structured Si is also tested as a surface-enhanced Raman spectroscopy (SERS) substrate showing a strong signal under 638 nm excitation with Raman enhancement factors (EFs) as high as 108. In particular, the capability of detecting Raman analyte down to 10−11 M for RhB and 10−10 M for 4-MBA is demonstrated, simultaneously assessing the enhanced near-field due to the LSPR originating from the processed surface roughness leading to the valuable performances achieved by the n + -n junction diodes. These results offer a new path toward the elaboration of high-efficiency applications of Si structured surfaces in the fields of photoelectric sensing and detection.

Localized surface plasmon resonance-enhanced photoelectrochemical immunoassay based on high-entropy yolk-shell Au@(ZnCdMnGaCu)xS

The yolk-shell structure has become a research hotspot in the field of photocatalysis in recent years due to its stability, movable yolk, and internal voids. However, yolk-shell has not been fully explored and applied in photoelectrochemical (PEC) immunoassays. In this work, a smartphone-based portable PEC immunoassay was constructed by using high-entropy yolk-shell Au@(ZnCdMnGaCu)xS as a photosensitive material, showing satisfactory detection with the assistance of localized surface plasmon resonance (LSPR). Specifically, a typical sandwich reaction introduces a detection antibody modified and labeled with gold nanoparticles (Au NPs) of alkaline phosphatase (ALP) into the system with the presence of prostate-specific antigen (PSA). Ascorbic acid (AA) content increased with increasing PSA and showed a linear enhancement of photocurrent at PSA concentrations of 0.01–50 ng mL−1 with a limit of detection of 8.94 pg mL−1. Additionally, the proposed assay technology not only provides a portable detection system for the immediate detection of tumor markers, but also offers a promising paradigm for the development of high-entropy materials.

Multi-species defect engineering synergistic localized surface plasmon resonance boosting photocatalytic CO2 reduction

Inadequate charge carrier kinetics and a scarcity of active sites still challenge photocatalytic CO2 reduction reaction (CO2RR). We exploit the synergy between multi-species defect engineering and the localized surface plasmon resonance (LSPR) effect in Bi/BiV1-mO4-m to address these limitations. Theoretical calculations show that V and O defects collectively modulate the work function of BiVO4, which induces hot electrons to transfer from Bi nanoparticles to BiV1-mO4-m. These electrons are then captured by O defects, confirmed by femtosecond transient absorption spectroscopy. Electron density is significantly increased at the O defects, enhancing CO2 adsorption and establishing it as a new reaction site. Bi/BiV1-mO4-m achieves photocatalytic CO2RR in pure water; Bi/BiV1-mO4-m achieves direct solar-driven photocatalytic CO2RR with a CO yield of 501 μmol/g/h under concentrated sunlight.

Theoretical study of a triple-band tunable terahertz metamaterial absorber with polarization insensitive and high refractive index sensing based on bulk Dirac semimetal

In this paper, a triple-band metamaterial absorber in the terahertz frequencies is proposed, and its refractive index sensing characteristics are analyzed, where the bulk Dirac semimetal (BDS) periodic array is on top of a photonic crystal slab backed with a metal ground plane. The simulation results show that the absorber achieves three perfect absorption peaks in the range of 3.4–5.2 THz, whose absorption rates are over 96%, and a maximum quality factor (Q) of 74.1. The designed absorber exhibits excellent polarization insensitivity and dynamic tunability; further, the tuning of the Fermi energy level of BDS enables the dynamic adjustment of absorption frequencies and absorption rates of these peaks. By analyzing the distributions of the electromagnetic field and different structural parameters, it is revealed that the absorber mainly dissipates the electromagnetic wave through coupled resonance and localized surface plasmon resonance (LSPR) effects to achieve perfect absorption. Further, the metamaterial absorber shows the capacity to detect analytes with varying refractive indices, and the absorber has a maximum sensitivity S of 405 GHz/RIU with high detection accuracy. This work provides novel design options for triple-band terahertz metamaterial absorbers and their potential applications in refractive index sensing.

Self-Assembly of Soft and Conformable Broadband Absorbing Nanocellulose-Gold Nanoparticle Composites.

Broadband light-absorbing materials are of large interest for numerous applications ranging from solar harvesting and photocatalysis to low reflection coatings. Fabrication of these materials is often complex and typically utilizes coating techniques optimized for flat and hard materials. Here, we show a self-assembly based strategy for generating robust but mechanically flexible broadband light-absorbing soft materials that can conform to curved surfaces and surface irregularities. The materials were fabricated by adsorbing large quantities of gold nanoparticles (AuNPs) on the nanofibrils of hydrated bacterial cellulose (BC) membranes by tailoring the interaction potential between the cellulose nanofibrils and the AuNPs. The highly efficient self-assembly process resulted in very dense multilayers of AuNPs on the nanofibrils, causing extensive broadening of the localized surface plasmon resonance band and a striking black appearance of the BC membranes. The nanocomposite materials showed an absorptance >96% in both the visible and the near-infrared wavelength range. The AuNP-functionalized BC membranes demonstrated excellent conformability to curved and structured surfaces and could adopt the shape of highly irregular surface structures without any obvious changes in their optical properties. The proposed self-assembly based strategy enables the fabrication of soft and conformable broadband light-absorbing nanocomposites with unique optical and mechanical properties using sustainable cellulose-based materials.

Coherent random fiber laser emission from CdSe/ZnS quantum dots.

We experimentally demonstrate the coherent random laser emission by combining CdSe/ZnS colloidal quantum dots (CQDs) with hollow optical fiber. Through the localized surface plasmon resonance (LSPR) induced by Ag nanoparticles (NPs), well-distinguished discrete spikes are observed from the Ag modified hollow fiber loaded with CdSe/ZnS QDs solution. In addition, coherent random laser action with low threshold is also realized in the hollow optical fiber filled with high packing-density CdSe/ZnS QDs even if the Ag NPs is not introduced. The self-assembled clusters of CdSe/ZnS QDs serve as the optical gain media as well as the strong scattering centers. The angle measurement experiments show that the directional emission of random laser can be adjusted by using different pumping manners. This facile, inexpensive, low pump threshold random laser could be widely used in photonic devices and display imaging.&#xD.

A novel stearic acid/expanded graphite/Fe3O4 composite phase change material with effective photo/electro/magneto-triggered thermal conversion and storage for thermotherapy applications

Composite phase change materials (CPCMs) have demonstrated high potential in thermotherapy; however, their poor energy conversion limits thermal−charge performance, thus negatively affecting their practical applications. Herein, we combined stearic acid (SA), expanded graphite (EG), and Fe3O4 nanoparticles (NPs) to obtain an 80 wt% SA/EG/Fe3O4 CPCM with multisource−triggered thermal conversion and storage abilities. The CPCM was equipped with a photothermal conversion facilitated by high light absorption of EG and localized surface plasmon resonance of Fe3O4. The high electrical conductivity of EG also offered the CPCM with an effective electrothermal conversion. An accelerated magnetothermal conversion was further achieved for the CPCM owing to the superparamagnetism of Fe3O4 NPs. Resultantly, the 80 wt% SA/EG/Fe3O4 CPCM could be facily charged as applied with either low−energy electricity (2.0 V), actual sunlight radiation (98−110 mW/cm2), or alternating magnetic field (120 W). In addition, it exhibited relatively high thermal storage capacity (152.4 J/g), excellent leakage resistance, and high thermal stability, conductivity, and cycling reliability. As in the form of a heat pack, the 80 wt% SA/EG/Fe3O4 CPCM maintained a heat release to a human back within 50–52 °C for 34 min, overtaking the criteria for high−temperature thermotherapy. The proposed multisource−triggered thermal conversion abilities and suitable thermal properties made SA/EG/Fe3O4 CPCM promising for multiple energy utilization and practical thermotherapy applications.

Titanium boride nanosheets with photo-enhanced sonodynamic efficiency for glioblastoma treatment

Sonodynamic therapy (SDT) has garnered significant attention in cancer treatment, however, the low-yield reactive oxygen species (ROS) generation from sonosensitizers remains a major challenge. In this study, titanium boride nanosheets (TiB2 NSs) with photo-enhanced sonodynamic efficiency was fabricated for SDT of glioblastoma (GBM). Compared with commonly-used TiO2 nanoparticles, the obtained TiB2 NSs exhibited much higher ROS generation efficiency under ultrasound (US) irradiation due to their narrower band gap (2.50 eV). Importantly, TiB2 NSs displayed strong localized surface plasmon resonance (LSPR) effect in the second near-infrared (NIR II) window, which facilitated charge transfer rate and improved the separation efficiency of US-triggered electron–hole pairs, leading to photo-enhanced ROS generation efficiency. Furthermore, TiB2 NSs were encapsulated with macrophage cell membranes (CM) and then modified with RGD peptide to construct biomimetic nanoagents (TiB2@CM-RGD) for efficient blood-brain barrier (BBB) penetrating and GBM targeting. After intravenous injection into the tumor-bearing mouse, TiB2@CM-RGD can efficiently cross BBB and accumulate in the tumor sites. The tumor growth was significantly inhibited under simultaneous NIR II laser and US irradiation without causing appreciable long-term toxicity. Our work highlighted a new type of multifunctional titanium-based sonosensitizer with photo-enhanced sonodynamic efficiency for GBM treatment. Statement of significanceTitanium boride nanosheets (TiB2 NSs) with photo-enhanced sonodynamic efficiency was fabricated for SDT of glioblastoma (GBM). The obtained TiB2 NSs displayed strong localized surface plasmon resonance (LSPR) effect in the second near-infrared (NIR II) window, which facilitated charge transfer rate and improved the separation efficiency of US-triggered electron-hole pairs, leading to photo-enhanced ROS generation efficiency. Furthermore, TiB2 NSs were encapsulated with macrophage cell membranes (CM) and then modified with RGD peptide to construct biomimetic nanoagents (TiB2@CM-RGD) for efficient blood-brain barrier (BBB) penetrating and GBM targeting. After intravenous injection into the tumor-bearing mouse, TiB2@CM-RGD can efficiently cross BBB and accumulate in the tumor sites. The tumor growth was significantly inhibited under simultaneous NIR II laser and US irradiation without causing appreciable long-term toxicity.

Less is more: surface-lattice-resonance-enhanced aluminum metasurface with giant saturable absorption for a wavelength-tunable Q-switched Yb-doped fiber laser

Resonant metasurfaces provide a promising solution to overcome the limitations of nonlinear materials in nature by enhancing the interaction between light and matter and amplifying optical nonlinearity. In this paper, we design an aluminum (Al) metasurface that supports surface lattice resonance (SLR) with less nanoparticle filling density but more prominent saturable absorption effects, in comparison to a counterpart that supports localized surface plasmon resonance (LSPR). In detail, the SLR metasurface exhibits a narrower resonance linewidth and a greater near-field enhancement, leading to a more significant modulation depth (9.6%) at a low incident fluence of 25 μJ/cm2. As an application example, we have further achieved wavelength-tunable Q-switched pulse generation from 1020 to 1048 nm by incorporating the SLR-based Al metasurface as a passive saturable absorber (SA) in a polarization-maintaining ytterbium-doped fiber laser. Typically, the Q-switched pulse with a repetition rate of 33.7 kHz, pulse width of 2.1 μs, pulse energy of 141.7 nJ, and signal-to-noise ratio (SNR) of greater than 40 dB at the fundamental frequency can be obtained. In addition, we have investigated the effects of pump power and central wavelength of the filter on the repetition rate and pulse width of output pulses, respectively. In spite of demonstration of only using the Al metasurface to achieve a passive Q-switched fiber laser, our work offers an alternative scheme to build planar, lightweight, and broadband SA devices that could find emerging applications from ultrafast optics to neuromorphic photonics, considering the fast dynamics, CMOS-compatible fabrication, and decent nonlinear optical response of Al-material-based nanoplasmonics.

The Fabrication of Gold Nanostructures as SERS Substrates for the Detection of Contaminants in Water.

Gold nanostructures (AuNSs) were used to fabricate surface-enhanced Raman spectroscopy (SERS) substrates. These AuNSs were produced using the solid-state dewetting method from thin films. The fragmentation process was studied at 300 °C, with durations of thermal treatment of 1, 3, 6, and 12 h. These SERS substrates were then employed to detect Rhodamine B (RhB) as the model analyte, simulating a contaminant in the water at a concentration of 5 ppm. The morphology of the AuNSs was examined using SEM, which revealed a spheroidal shape that began to coalesce at 12 h. The size of the AuNSs was estimated to range from 22 ± 7 to 24 ± 6 nm, depending on the annealing time. The localized surface plasmon resonance of the AuNSs was determined using absorption spectroscopy, showing a shift as the annealing time increased. The SERS signals of RhB adsorbed on the AuNS substrates were validated by performing a 10 × 10 point map scan over each sample surface (1, 3, 6, and 12 h), and a comparative analysis showed no significant differences in the positions of the bands; however, variations in intensity enhancement ranged from 5 to 123 times at 6 and 1 h, respectively.

Silver Nanoparticles: A Comprehensive Review of Synthesis Methods and Chemical and Physical Properties.

Recently, silver nanoparticles (NPs) have attracted significant attention for being highly desirable nanomaterials in scientific studies as a result of their extraordinary characteristics. They are widely known as effective antibacterial agents that are capable of targeting a wide range of pathogens. Their distinct optical characteristics, such as their localized surface plasmon resonance, enlarge their utilization, particularly in the fields of biosensing and imaging. Also, the capacity to control their surface charge and modify them using biocompatible substances offers improved durability and specific interactions with biological systems. Due to their exceptional stability and minimal chemical reactivity, silver NPs are highly suitable for a diverse array of biological applications. These NPs are produced through chemical, biological, and physical processes, each of which has distinct advantages and disadvantages. Chemical and physical techniques often encounter issues with complicated purification, reactive substances, and excessive energy usage. However, eco-friendly biological approaches exist, even though they require longer processing times. A key factor affecting the stability, size distribution, and purity of the NPs is the synthesis process selected. This review focuses on how essential it is to choose the appropriate synthesis method in order to optimize the characteristics and use of silver NPs.

Preparation of C@CuNi/TiO2 with a local surface plasmon resonance for photocatalytic degradation of organic dyes and antibiotics under visible light irradiation

A composite photocatalyst with carbon-coated CuNi nanoparticles-loaded TiO2 nanotubes (C@CuNi/TiO2) was synthesized via a microwave hydrothermal alkali stripping method combined with subsequent in-situ carbothermal reduction. The structure, morphology, and surface chemical composition were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The findings demonstrate that the microwave hydrothermal alkali peeling enables the formation of a three-dimensional C@CuNi/TiO2 composite structure. The results of transient photocurrent response (i-t) and electrochemical impedance spectroscopy under visible light demonstrate that C@CuNi/TiO2 exhibits a reduced rate of electron-hole recombination and lower surface resistance compared to C@TiO2, C@Cu/TiO2, and C@Ni/TiO2. After a two-hour exposure to visible light, the composite photocatalyst C@CuNi/TiO2, featuring a molar ratio of 2 % CuNi nanoparticles to TiO2 nanotubes, exhibited remarkable degradation activity towards organic dyes (Rhodamine B (RhB), Methylene Blue (MB), Methyl Orange (MO)), as well as antibiotics (tetracycline (TC) and levofloxacin (LVFX)). After 5 cycles of photocatalytic reaction, the photodegradation activity of RhB remained above 79 %. It is indicated that CuNi nanoparticles effectively trap and enrich photoelectrons through the photoexcitation of TiO2 nanotubes. Additionally, the local surface plasmonic resonance (LSPR) effect of CuNi nanoparticles reduces the recombination rate of photogenerated electron/hole and the electron transport resistance in the composite photocatalyst, thereby enhancing its overall photocatalytic activity.

Plasmonic molybdenum carbide MXene nanosheets for highly efficient and stable perovskite solar cells

Besides the excellent metallic electrical conductivity, high carrier mobility, and high optical transmittance, the two-dimensional MXenes exhibiting impressive optical and plasmonic properties have been explored to photodiodes. However, their potential use of surface plasmons oscillating in perovskite solar cells has not been studied. Herein, we incorporate, for the first time, Mo2CTx MXene nanosheets with characteristic plasmonic absorption in the whole visible region into the perovskite active layer. First, the presence of Mo2CTx nanosheets in the perovskite film increases the perovskite grain size due to the decreased growth rate and passivation of the defects around the grain boundaries through strong interaction with undercoordinated Pb2+. Furthermore, with the help of the localized surface plasmon resonance effect of Mo2CTx nanosheets, the exciton binding energy in the perovskite absorber is reduced, which suggests the efficient exciton dissociation and enhanced charge separation. Consequently, Mo2CTx nanosheets based perovskite solar cell device exhibits a champion power conversion efficiency (PCE) of 24.05 %. It is worth noting that the unencapsulated devices demonstrate considerably improved stability, maintaining about 89.25 % of the initial PCE after aging in air for 3000 h. This fascinating strategy provides more opportunities of the functional MXene materials for the perovskite optoelectronics.

Novel PtCu/MIL-101(Cr) for efficient degradation of bisphenol A: Photothermal synergism promoted by the localized surface plasmon resonance effect

Semiconductor photocatalysis is one of the most useful methods to solve environmental pollution problems. Herein, nanomaterial PtCu/MIL-101(Cr) was produced by an improved hydrothermal technique. The composite exhibited excellent photocatalytic performance with 99.7 % BPA degradation under 100 min visible light irradiation. First, the PtCu alloy has the effect of the local surface plasmon resonance effect, which can convert the photons to hot electrons and increase the reaction temperature. The synergistic effect (1+1>2) between photocatalysis and thermocatalysis significantly improved the photocatalytic efficiency. Second, the bimetallic alloying lowered the metals' work function and reduced the Schottky barrier between the PtCu alloy and MIL-101(Cr), which effectively promoted the carrier transfer. The ·O2-, ·OH and h+ were dominant reactive substances in the degradation process. The intermediates and degradation pathways of BPA were analyzed by 3D-EEM. The reaction mechanism was proposed based on theoretical calculations and experimental analysis. This work provides new directions for designing photothermal synergistic green catalysts and purifying the environment.