Separation Efficiency Of Photogenerated Carriers Research Articles

Sm-doped ZnO with enhanced photocatalytic performance toward destruction of RhB

In this work, Sm-doped ZnO was prepared by a Sol-Gel method. The structure, morphology, composition and optical properties of the prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), surface photovoltage spectrum (SPS) and X-ray photoelectron spectros­copy (XPS). Sm-doping results in high specific surface area and boosted photogenerated carriers separation efficiency, and produces more active free radicals to participate in the photocatalytic reaction. Photocatalytic activities of the samples toward removal of rhodamine B(RhB) were evaluated under UV light irradiation, the results display that Sm-doped ZnO shows higher photocatalytic activity than the reference ZnO.

Broad-spectrum absorptive ZnCr LDHs/ZIF-67 S-scheme heterojunction for hydrogen evolution reaction under visible light irradiation

Zinc-chromium layered double hydroxides (ZnCr LDHs) occupy longer wavelength of the absorption range due to the existence of trivalent Cr ion, which is beneficial to capture more photons. However, the catalytic performance of single ZnCr LDHs is limited by the feeble dynamics. Herein, the 2D/3D S-scheme heterojunction ZnCr LDHs/ZIF-67 was coupled together by moderate electrostatic self-assembly to block the recombination of photogenerated charges on single ZnCr LDHs. Thanks to the successful formation of S-scheme heterojunction, the prepared ZZC-25 heterojunction presents a high hydrogen evolution of about 3.0 mmol g−1 h−1, which is 308.34 times and 4.82 times higher than that of ZnCr LDHs and ZIF-67, respectively. The results demonstrate that the incorporation of an S-scheme heterojunction serves as an effective strategy to enhance the photocatalytic performance of a single wide spectrum semiconductor. The present study offers experimental guidance for the efficient separation of photo-generated carriers in LDHs-based wide-spectrum semiconductors.

In Situ Construction of CuTCPP/Bi4O5Br2 Hybrids for Improved Photocatalytic CO2 and Cr(VI) Reduction.

Global warming and heavy metal pollution pose tremendous challenges to human development, and photocatalysis is considered to be an effective strategy to solve these problems. Herein, copper(II) tetra (4-carboxyphenyl) porphyrin (CuTCPP) molecules were successfully in situ loaded onto Bi4O5Br2 by a hydrothermal approach. A series of experimental results show that the light absorption capacity and photogenerated carrier separation efficiency were synchronously enhanced after the construction of CuTCPP/Bi4O5Br2 composites. Hence, the as-prepared composites possess significantly improved photocatalytic ability for both CO2 and Cr(VI) reduction. Specifically, CuTCPP/Bi4O5Br2-2 achieves a CO generation rate of 17.14 μmol g-1 under 5 h irradiation, which is twice as high as that of Bi4O5Br2 (8.57 μmol g-1). Besides, the optimized CuTCPP/Bi4O5Br2-2 also exhibits a removal rate of 61.87% for Cr(VI) within 100 min under irradiation. Furthermore, the mechanism of CO2 and Cr(VI) photoreduction was explored by in situ Fourier transform infrared spectroscopy and capture experiments, respectively. This work can be a reference toward the construction of photocatalysts with high activity for solar energy conversion.

Constructing multiple active sites of Bi2WO6 for efficient photocatalytic NO removal and NO2 inhibition

Insufficient photocatalytic NOx oxidation capacity will lead to excessive toxic by-products (NO2), which still seriously restrict its practical application. Herein, the multiple active sites (Cl, Bi0 and OVs) modified Bi2WO6 has been established by in-situ synthesis method. The synergistic effect of multiple active sites greatly increased the photo-electric properties of the Bi2WO6, resulting in the boosting photocatalytic NOx deep oxidation to nitrate. The visible light driven OVs-Bi@BWO-Cl catalyst exhibited a highest NO conversion efficiency (67.3 %) with extremely low NO2 concentration (17.9 ppb). The synergism of structural regulation from the OVs with Cl-doping and surface plasmon resonance of Bi0 significantly enhanced light absorption and provided a fast charge transport channel, improving the separation efficiency of photo-generated carriers. The in-situ DRIFTS and density functional theory (DFT) results shown that the synergistic effect by multiple active sites could enhance the adsorption and activation of reactants to accelerate the processes of H2O/O2-to-ROS and decrease the energy barrier of NO removal to promote deep oxidation of NO-to-NO3−. This work can provide ideas for the design and preparation of the catalyst for safe photocatalytic environment purification.

Engineering oxygen vacancies and morphology of BiOCl microspheres via electrification to enhance visible light photocatalytic performance

Enhancing the separation efficiency of photo-generated carriers and the surface area of catalysts is beneficial to improve the photocatalytic performance, which is critical to achieving application of photocatalysis in practical environmental remediation. In this work, the BiOCl microspheres were treated with electrification for the first time to synergistically tune oxygen vacancies (OVs) and microstructure. With 6h electrification, the photocatalytic performance of BiOCl-6 microspheres was significantly enhanced, which can not only degrade organic contaminants, but also effectively reduce toxic heavy metal ions. The photocatalytic reaction rates for methyl blue (MB), ciprofloxacin (CIP) and hexavalent chromium Cr(VI) reached 0.071, 0.056 and 0.097min-1, respectively, which were 5.1, 7.0 and 8.1 times higher than that of pristine BiOCl. The density functional theory (DFT) calculations and experimental investigation suggest that the designed OVs facilitates the separation of photo-excited carriers and expands the light adsorption range of BiOCl. Meanwhile, the increased surface area of BiOCl-6 microspheres enhances the adsorption for contaminants and provides more active sites for photocatalytic reaction. This work provides a new approach to synergistically enhance photocatalytic performance for photocatalysts by vacancy engineering and morphology control.

Enhanced CO2 photoreduction to CO by small-size NH2-UiO-66 nanoparticles immobilization on Mo2C

The small-size and efficient charge separation of MOFs catalysts are essential for improving photocatalytic performance. In this work, a series of small-size NH2-UiO-66 nanoparticle-modified Mo2C photocatalysts were successfully prepared by hydrothermal synthesis with in situ growing NH2-UiO-66 on the surface of Mo2C. The addition of Mo2C can not only obtain small-size NH2-UiO-66 nanoparticles, but also significantly increase the separation efficiency of photo-generated carriers and prolongs the carrier lifetime, thereby promoting the photoreduction of CO2 in water vapor with excellent stability. The resulting 11-Mo2C/NH2-UiO-66 (11-MCNU) exhibits excellent catalytic activity for CO2 reduction to CO product at room temperature and atmospheric pressure. The yield of CO can reach 11 μmol g−1 in the absence of organic solvents, sacrifice agents and photosensitizers, which is much higher than that of the isolated NH2-UiO-66 and Mo2C.

Efficient separation of photo-generated carriers for in-situ induction of PDI cation radicals to enhance the photocatalytic performance of PDI supramolecules

In order to investigate whether the formation of hydrogen bonds can affect the degradation products of pollutants, a photocatalyst PDI-SE was obtained by end substituting perylene tetracarboxylic dianhydride with serine (SE) in this paper. As a reference, PDI-IS with isopropylamine (IS) terminal alkyl substitution was synthesized simultaneously. Their photocatalytic performance to decompose phenol and tetrabromobisphenol A (TBBPA) were investigated. PDI-SE could degrade 79.3% of phenol or 68.4% of TBBPA within 4 h under visible light. The degradation products of TBBPA were tracked using high-resolution mass spectrometry. The morphology, composition, structure, and optoelectronic properties of two photocatalysts, particularly their transient absorption spectra and fluorescence lifetime were studied. We also conducted theoretical calculations on their binding energy with phenol or TBBPA, distribution and separation of electron and hole of excited state PDI-SE and PDI-IS supramolecules. Due to the formation of hydrogen bonds the binding energy of PDI-SE with phenol or TBBPA is 1.24 eV or 1.99 eV, which is stronger than that of PDI-IS (0.85 eV or 1.66 eV). Although both PDI-SE and PDI-IS can form free radical cations in excited states, the high separation of electrons and holes of PDI-SE leads to a longer lifetime of free radical cations, so caused its excellent photocatalytic activity compared to PDI-IS. This article proposes a new strategy based on molecular design to promote efficient separation of photogenerated electrons and holes, thereby forming stronger oxidizing PDI cationic radicals in situ to enhance the photocatalytic performance of PDI supramolecules.

Vanadium-doped metal-organic framework@Znln2S4 core-shell heterojunction-attenuated photoelectrochemical immunoassay

Considering that cancer has become the second leading cause of death in humans, it is essential to develop an analytical approach that can sensitively detect tumor markers for early detection. We report an attenuated photoelectrochemical (PEC) immunoassay based on the organic-inorganic heterojunction 10MIL-88B(FeV)/ZnIn2S4 (10M88B(FeV)/ZIS) as a photoactive material for monitoring carcinoembryonic antigen (CEA). The 10M88B(FeV)/ZIS heterojunctions have excellent light-harvesting properties and high electrical conductivity, which are attributed to the advantages of both organic and inorganic semiconductors, namely, remarkable photogenerated carrier separation efficiency and long photogenerated carrier lifetime. Horseradish peroxidase (HRP) in the presence of H2O2 can catalyze 3,3′-diaminofenamide (DAB) producing brown precipitates (oxDAB), which is then loaded onto the 10M88B(FeV)/ZIS heterojunction to reduce the photocurrent and enable the quantitative detection of CEA. Under optimal conditions, the photocurrent values of the PEC biosensor are linearly related to the logarithm of the CEA concentrations, ranging from 0.01 ng mL−1 to 100 ng mL−1 with a detection limit (LOD) of 4.0 pg mL−1. Notably, the accuracy of the PEC biosensor is in agreement with that of the human CEA enzyme-linked immunosorbent assay (ELISA) kit.

BiOCl modified TiO2 based catalyst with enhanced hydrogen generation properties under visible light via promote photogenerated electron-hole separation

Due to its wide band gap and low photogenerated carrier separation efficiency, TiO2 has an undesirable photocatalytic activity. In the present work, BiOCl was hydrothermally deposited on TiO2 and BiOCl/TiO2 composites with different ratios were obtained. The results show that 30 % BiOCl/TiO2 has the best performance of 1354.94 μmolg−1h−1, which is 18.4 times than pure TiO2 and 73.1 times than pure BiOCl. The significant increase in the photocatalytic efficiency of BiOCl/TiO2 composites is attributed to the reduction of their bandgap width and the fast separation of photogenerated electron-hole pairs. This work brings a new idea to increase the photocatalytic hydrogen production capability of TiO2.

Constructing efficient Ti4O7/PbO2 heterostructured photoelectrode for water remediation

Photoelectrocatalytic oxidation (PEC) technology is considered to be an efficient process for the treatment of organic wastewater, and its performance depends on the characteristics of the PEC photoanodes. Therefore, the construction of heterogeneous nanostructured photoelectrodes based on suitable semiconductor materials for fast induced carrier transfer efficiency is essential for a high-performance PEC technique. Herein, titanium suboxide/lead (IV) oxide (Ti4O7/PbO2) ceramic photoelectrode with efficient PEC performance was synthesized by coupling PbO2 nanospheres with Ti4O7 through a hydrothermal method. To maximize the PEC performance of the ceramic electrodes, the Ti4O7/PbO2 nano-heterostructures were optimized by modulating the hydrothermal temperature. The optimized ceramic electrodes possessed a low Tafel slope, a low charge-transfer resistance and a good photocurrent response. Ti4O7/PbO2-110 exhibited an efficient PEC activity (approximately 92.21%) for the degradation of reactive brilliant blue KN-R. The efficient PEC performance of Ti4O7/PbO2-110 arose from the formation of a type II heterojunction between Ti4O7 and PbO2, which achieved efficient photogenerated carrier separation and facilitated the formation of intermediate active species. This work not only validates the efficient performance of Ti4O7/PbO2-110 for PEC water purification but also provides a reference strategy for the preparation of heterostructured ceramic photoelectrodes with a high PEC efficiency.

Fabrication of oxygen-vacancy-adjustable Yb3+/Er3+ co-doped BiOBr 3D flowerlike hierarchical architectures with enhanced photocatalytic activity under broad spectrum (UV/vis/NIR) excitation

A novel Yb3+/Er3+ co-doped BiOBr photocatalyst with 3D flowerlike hierarchical architectures were successfully fabricated through self-assembled process without any templates under hydrothermal conditions, and the structure and properties of the photocatalysts were characterized. The results indicate that Yb3+ ions and Er3+ ions are successfully doped into the lattice of BiOBr, and the as-obtained photocatalyst can respond the NIR light and emit red and green light due to the up-conversion effect of the rare-earth ions. Meanwhile, with co-doped Yb3+/Er3+ ions content increasing, oxygen vacancy concentration in the photocatalyst rises. The oxygen vacancy will form the intermediate energy band, which can decrease the photon energy required for electronical transition, and thus help to utilize the luminous energy generated by up-conversion luminescence. Moreover, the appropriate introduction of defects (oxygen vacancy defect and impurity atom) can further promote the transfer and separation efficiency of photo-generated carriers. Hence, Yb3+/Er3+ co-doped BiOBr photocatalyst exhibits enhanced photocatalytic properties under broad spectrum (UV/vis/NIR) excitation, which is about 4 times as high as that of pure BiOBr.

Unveiling the cobalt vanadate supported hexagonal boron nitride nanocomposite for photocatalytic wastewater treatment: Enhanced degradation of dyes, antibiotics, and real industrial wastewater

In recent years, the expansion of industrial sectors has imposed a burden on water resources globally owing to unsustainable consumption and discharges into the environment. Here, a Co3V2O8 (CV)/hexagonal boron nitride (HBN) heterojunction has been constructed using an applicable solid-state technique that produces efficient photocatalytic action during water cleanup activities. The nanocomposite was studied utilizing different approaches such as XRD, SEM, TEM, FT-IR, EDX, XPS, UV–Vis spectroscopy, EIS, PL, BET, and M − S plots. The pristine HBN has a band gap of 5 eV, while the CV/HBN nanocomposite has a band gap of 1.8 eV. According to our findings, the photocatalyst has a high degradation ratio of up to 98.1%, 89.8%, 87.5%, 96.5%, and 90.2% in brilliant cresyl blue (CB), rhodamine-B (Rh–B), amoxicillin (AMX), metronidazole (MNZ), and industrial wastewater (IW) under visible light irradiation, correspondingly. It emphasizes that the remarkable photocatalytic activity is mostly due to the photocatalyst's superior performance and dominant absorption of visible light, as well as the efficient photogenerated carrier separation brought about by the interaction of cobalt vanadate and HBN. The catalyst demonstrated stable behavior, adhering to five reuse cycles. The present research reveals that the CV/HBN nanocomposite is a very stable and active photocatalyst that may be used as an alternative to costlier noble metal-based photocatalysts in photocatalysis applications. When compared to untreated IW, the degraded IW sample exhibits superior plant growth, which is visible from the phytotoxicity tests.

High-Performance Self-Powered Photoelectrochemical Ultraviolet Photodetectors Based on an In2O3 Nanocube Film.

Ultraviolet photodetectors (UV PDs) have attracted significant attention due to their wide range of applications, such as underwater communication, biological analysis, and early fire warning systems. Indium oxide (In2O3) is a candidate for developing high-performance photoelectrochemical (PEC)-type UV PDs owing to its high UV absorption and good stability. However, the self-powered photoresponse of the previously reported In2O3-based PEC UV PDs is unsatisfactory. In this work, high-performance self-powered PEC UV PDs were constructed by using an In2O3 nanocube film (NCF) as a photoanode. In2O3 NCF photoanodes were synthesized on FTO by using hydrothermal methods with a calcining process. The influence of the electrolyte concentration, bias potential, and irradiation light on the photoresponse properties was systematically studied. In2O3 NCF PEC UV PDs exhibit outstanding self-powered photoresponses to 365 nm UV light with a high responsivity of 44.43 mA/W and fast response speed (20/30 ms) under zero bias potential, these results are superior to those of previously reported In2O3-based PEC UV PDs. The improved self-powered photoresponse is attributed to the higher photogenerated carrier separation efficiency and faster charge transport of the in-situ grown In2O3 NCF. In addition, these PDs exhibit excellent multicycle stability, maintaining the photocurrent at 98.69% of the initial value after 700 optical switching cycles. Therefore, our results prove the great promise of In2O3 in self-powered PEC UV PDs.

Halogen-doped ultrathin Bi2WO6 for promoted separation of photogenerated carriers and efficient photocatalysis

Although photocatalysis is a viable and sustainable technique to remove refractory pollutants from wastewater, it is plagued by the low separation efficiency of photo-generated carriers. Herein, in situ surfactants (CTAC, CTAB, and DTAI) assisted synthesis of halogen-doped ultra-thin Bi2WO6 (BWO) nanosheets with oxygen vacancies, which efficiently degraded RhB and TC under visible light. Surfactant as a halogen source can also prevent the formation of BWO layered structures, thus making the sample thinner and thus reducing the transmission distance of photogenerated electrons. The degradation rates of rhodamine B (RhB) and tetracycline (TC) by BWO-Cl-90 and BWO-Br-90 upon visible light illumination are 5.8 times / 5.5 times and 2.5 times / 2.8 times by those of pure BWO, respectively. The free radical trapping experiments and ESR reveal that singlet oxygen (1O2) and photogenerated holes (h+) are the main active free radicals in the degradation of organic pollutants by BWO-Cl-90, while the superoxide radical (·O2-) and photogenerated holes (h+) play the main roles for BWO-Br-90. The photocatalytic mechanism is proposed. In addition, the EIS, photocurrent and photoluminescence (PL) experiments show that halogen doping improves the separation ability of photogenerated carriers. This study reveals a practical method to modify Bi2WO6-based materials for effective wastewater treatment and purification.

Constructing stable type-II NaLiTi3O7/La2S3 heterojunctions for efficient photocatalytic charge separation and hydrogen production

Designing titanium-based oxides with efficient photogenerated carrier separation is an essential approach to enhance their photocatalytic hydrogen production performance. ALiTi3O7 possesses excellent stability, corrosion resistance, and non-toxicity. More importantly, its stoichiometry can be changed along with the variations in A-site elements and Li content, leading to tunable redox potentials of the conduction band minimum (CBM) and valence band maximum (VBM). Exploring the possible application of such materials in the field of photocatalysis is crucial for developing novel and efficient titanium-based photocatalysts. As a member of the family, NaLiTi3O7 (NLT) has a large bandgap, limiting its application as visible light photocatalyst. To address this issue, non-toxic La2S3 (LS) narrow-bandgap semiconductor was incorporated to form a heterojunction. The characterization techniques have revealed the structural and interfacial characteristics of the NLT-LS heterojunction, while the Infrared, Raman, UV–Vis diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS), and work-function tests elucidated the influence of the interface interaction on charge carrier separation mechanism. The test results further demonstrated that the formation of a type II heterojunction facilitated the transfer of photogenerated electrons from the conduction band of LS to the conduction band of NLT under light radiation. Simultaneously, the induced holes were confined to the valence band of LS. This charge transfer characteristic significantly improved the separation efficiency of the photogenerated carriers in the heterojunction, ultimately resulting in a photocatalytic hydrogen production rate of 102.4 μmol h−1 g−1 for the NLT-LS2 sample, which is ∼8 times higher than that of pure NLT and almost no decay after four cycles.

Three-dimensional donor-acceptor conjugated porous polymers based on metal-porphyrin and triazine for highly effective photodegradation of organic pollutants in water

Three-dimensional donor-acceptor (D-A) type conjugated porous polymers (CPPs) was designed and synthesized via imine condensation of copper tetraaminoporphyrin (CuTAPP) as donor and 1,3,5-tris-(4-formyl phenyl) triazine (TFPT) as acceptor, named as CuPT-CPP. The CuPT-CPP possesses a high specific surface area (73.7 m2/g) and excellent photophysical properties. The simultaneous introduction of the organometallic molecules and D-A structures in CuPT-CPP could be broadened the visible-light response range (400–800 nm) and facilitated efficient photogenerated carrier separation and transportation. As heterogeneous photocatalysts, CuPT-CPP has excellent photocatalytic performances under visible light irradiation, leading to excellent model pollutant rhodamine B degradation efficiency up to about 100% in 3 h, it has superb stability and reusability during the photocatalytic processes, and CuPT-CPP also exhibited broad substrate adaptability, which could photocatalytic degradation of methylene blue (MB), methyl orange (MO), and tetracycline hydrochloride (TC). This work indicates that three-dimensional D-A type porphyrin- and triazine-based CuPT-CPP has great potential in the practical application of photocatalysis.

Efficient photocatalytic hydrogen generation by CeCO3OH/TiO2 composites

Due to its low photogenerated carrier separation efficiency and wide band gap, the photocatalytic activity of TiO2 is not ideal. In this work, CeCO3OH/TiO2 composites were successfully prepared by a simple hydrothermal method. A series of characterisations shows that the CeCO3OH/TiO2 composites improves the photogenerated carrier separation efficiency, narrowes the band gap width and increases the visible light absorption capacity compared with the monomer, enhancing the photocatalytic hydrogen evolution performance. Under visible light irradiation, 20% CeCO3OH/TiO2 exhibites the highest photocatalytic hydrogen production performance of 2386.16 μmol g−1 h−1, which is 18.7 times higher than that of pure TiO2 and 25.8 times higher than that of pure CeCO3OH. It provides ideas for the development of more efficient photocatalytic materials and technologies.

Effect of polarization electric field in photodegradation over ε-Cd(IO3)2 photocatalyst against antibiotics and dyes

The efficient photogenerated carriers separation is the key factor in enhancing the activity of photocatalysts to solve environmental pollution problems. The internal polarized electric fields in polar materials most likely provide a more direct and stronger driving force for photogenerated carriers separation. Here, we investigate polar ε-Cd(IO3)2 (CIO) with two different morphologies as an efficient photocatalyst for the photodegradation of antibiotics and dyes. According to the theoretical calculation of the ratios of mh*/me* along three different crystal axis directions, the photogenerated carrier separation efficiency along the c-axis direction is the largest, which matches the direction of the polarized electric field in the crystal. The internal polarized electric field promotes the separation of photogenerated carriers, leading to a high transfer efficiency of the catalyst. Moreover, photodegradation experiments demonstrate that the photocatalytic activity of CIO-1 is approximately 3 times that of TiO2 P25. This study provides some insights that might aid the development of polar photocatalysts with superior performance.

Cu, B co-modification boosted the photogenerated carrier separation efficiency in C3N4 for enhanced hydrogen evolution

In this work, g-C3N4 (U1W1–CNS) were prepared by calcination and Cu, B co-modified U1W1–CNS (Cu, B–CNS) was successfully fabricated by cryo-ultrasonic loading. B doping formed the unfavourable sub-centers and the Cu loading forms the electron-rich centre, which enhances the built-in electric field on the surface of U1W1–CNS. Hence, the 0.03Cu, 0.05B–CNS record a superior photocatalytic performance the hydrogen production rate reached to 1067 umolg−1h−1, which was 152, 10 and 1.67 times higher than that of U1W1–CNS (7 μmolg−1h−1), BCN (104 μmolg−1h−1) and 0.03Cu–CNS (638 μmolg−1h−1), respectively. This research provides new ideas for the design of U1W1–CNS photocatalyst with high performance photocatalytic hydrogen evolution.

Highly efficient visible-light driven dye degradation via 0D BiVO4 nanoparticles/2D BiOCl nanosheets p-n heterojunctions

The construction of hybrid heterojunction photocatalysts is an effective strategy to improve the utilization of photogenerated carriers and photocatalytic activity. To enhance the separation distance of photogenerated carriers and accelerate the effective separation at the heterojunction of the interface, a unique 0D-2D hierarchical nanostructured p-n heterojunction was successfully fabricated in this work. BiOCl (BOC) nanosheets (p-type) were in situ grown on BiVO4 (BVO) nanoparticles (n-type) using the microemulsion-calcination method for highly efficient visible-light-driven organic dye degradation. Compared with pure BVO (the degradation rate of rhodamine B (RhB): about 32.0% in 55 min, the mineralization rate: 24.9% in 120 min), the RhB degradation rate can reach about 99.5% in 55 min and the mineralization rate of 62.1% in 120 min by utilizing BVO/25%BOC heterojunction photocatalyst under visible light irradiation. Various characterizations demonstrate that the formation of BVO/BOC p-n heterojunction greatly facilitates photogenerated carriers separation efficiency. Meanwhile, the results of the scavenging experiments and electron spin resonance tests indicate that ·O2− and h+ are the prominent active species for Rh B degradation. In addition, possible degradation pathways for Rh B were proposed using LC-MS tests. This work proves that building low dimensional p-n heterojunction photocatalysts is a promising strategy for developing photocatalysts with high efficiency.