Efficient Electron-hole Separation Research Articles

Engineering Charge Transfer Characteristics in ZnO NRs/Ag2O NPs p-n Heterojunctions: Toward Highly Efficient and Recyclable Photocatalysts.

Staggered gap p-n heterojunction ZnO nanorods/Ag2O nanoparticles, a paradigm of photocatalysts, were developed via engineering the hydrothermal and coprecipitation method. Under simulated sunlight, the photocatalytic characteristics of ZnO/Ag2O(Zn/A) heterojunctions with varying mole ratios (from 8:1 to 8:4, named Zn/A-1-Zn/A-4) were systematically evaluated through the degradation of methylene blue (MB). The influence of key experimental variables, including photocatalyst concentration, MB concentration, and solution pH, on the photocatalyst performance was further analyzed. The incorporation of Ag2O enhanced visible-light absorption, improved electron-hole separation efficiency, and significantly improved the photocatalytic recyclability of the Zn/A heterojunctions. Additionally, metallic Ag generated during photodegradation was found to enhance the photocatalytic activity further. Kinetic studies indicated that the photocatalytic degradation of MB followed pseudo-first-order kinetics, with the Zn/A-3 heterojunction showing the highest photocatalytic activity, achieving a degradation rate constant (k) of 0.028 min-1. Scavenger experiments confirmed that •OH radicals, holes (h+), and superoxide radicals (•O2-) were the primary reactive species involved in the degradation process. The photocatalytic mechanism was identified as a Z-scheme charge transfer system, facilitating efficient charge separation. Moreover, the Zn/A-3 heterojunction exhibited remarkable recyclability, retaining >91% of the photocatalytic activity after five cycles. This study demonstrates the potential of Zn/A heterojunctions for practical applications in industrial wastewater treatment using solar energy.

2D/2D Hydrogen-Bonded Organic Frameworks/Covalent Organic Frameworks S-scheme Heterojunctions for Photocatalytic Hydrogen Evolution.

Hydrogen-bonded organic frameworks (HOFs) demonstrate significant potential for application in photocatalysis. However, the low efficiency of electron-hole separation and limited stability inhibit their practical utilization in photocatalytic hydrogen evolution from water splitting. Herein, the novel dual-pyrene-base supramolecular HOF/COF 2D/2D S-scheme heterojunction between HOF-H4TBAPy (Py-HOF, H4TBAPy represents the 1,3,6,8-tetrakis (p-benzoic acid) pyrene) and Py-COF was successfully established using a rapid self-assembly solution dispersion method. Experimental and theoretical investigations confirm that the size-matching of two crystalline porous materials enables the integrated heterostructure material with abundant surface reaction sites, strong interaction, and an enhanced S-scheme built-in electric field, thus significantly improving the efficiency of photogenerated charge carrier separation and stability. Notably, the optimal HOF/COF heterojunction achieves a photocatalytic hydrogen evolution rate of 390.68 mmol g-1 h-1, which is 2.28 times higher than that of pure Py-HOF and 9.24 times higher than that of pure COF. These findings precisely acquire valuable atomic-scale insights into the ingenious design of dual-pyrene-based S-scheme heterojunction. This work presents an innovative perspective for forming supramolecular S-scheme heterojunctions over HOF-based semiconductors, offering a protocol for designing the powerful and strong-coupling S-scheme built-in electric fields for efficient solar energy utilization.

Giant Colloidal Quantum Dot/α-Ga2O3 Heterojunction for High Performance UV-Vis-IR Broadband Photodetector.

Broadband optoelectronics, which extend from the UV to IR regions, are crucial for imaging, autonomous driving, and object recognition. In particular, photon detection efficiency relies significantly on semiconductor properties, such as absorption coefficients and electron-hole pair generation rate, which can be optimized by designing a suitable p-n junction. In this study, we devise giant PbS colloidal quantum dots (G-PbS CQDs) that exhibit high absorption coefficients and broadband absorption. To leverage these exceptional optical properties, we combine G-PbS CQDs with an ultrawide-bandgap semiconductor, α-Ga2O3, and create an efficient G-PbS CQD/α-Ga2O3 heterojunction photodetector that exhibits high performance across the UVC-vis-NIR spectrum range. The resultant heterojunction facilitates efficient electron-hole pair separation at the G-PbS CQD/α-Ga2O3 heterojunction. Furthermore, we utilize transparent graphene electrodes to overcome the limitations of conventional transistor-type device structures and the substantial optical losses induced by opaque metal electrodes. This strategy maximizes the light-collection area and results in an approximately 3-orders of magnitude higher responsivity (55.5 A/W) and specific detectivity (1.66 × 1013 Jones) compared to devices with opaque metal electrodes.

Dual Electric Field Coupling with Tunable Schottky Barrier Synergistically Regulating Electronic Configuration in CoP@Ni‐CdS Heterojunction for Efficient Photocatalytic H2 Evolution

AbstractDesigning and exploiting visible‐light‐responsive materials that converts solar into chemical energy is promising in achieving green energy sustainability, but addressing low electron–hole separation efficiency and sluggish surface kinetic process remains formidable challenges. Herein, a novel CoP@Ni‐CdS Schottky junction composed of Ni‐doped CdS nanorods and quasi‐metallic CoP nanoparticles is constructed via a simple hydrothermal–calcination method. Experiments and theoretical calculations demonstrate that magnetic Ni‐doping not only induces a spin‐polarized electric field and enhances the built‐in interfacial electric field strength, but also rises the Schottky barrier height at the heterointerface, which synergistically accelerates the separation efficiency of photoinduced charges and modulates the electronic configuration of the active site to optimize the adsorption–desorption behaviors for H2O molecules and H* intermediates. Therefore, the designed CoP@Ni‐CdS catalyst exhibits an exceptional photocatalytic performance with H2 evolution rate of 42.14 mmol g−1 h−1 with the apparent quantum efficiencies of 16.8% at 420 nm, which is 14.14 and 2.21 times higher than that of pristine CdS and Ni‐CdS, respectively. This work provides in‐depth insights into fabricating dual electric fields, tuning the Schottky barrier and modulating the electronic configuration of active sites in Schottky heterojunction for ameliorative photocatalytic activity.

Introducing Oxygen Vacancies into a WO3 Photoanode through NaH2PO2 Treatment for Efficient Water Splitting.

WO3, with a high light absorption capacity and a suitable band structure, is considered a promising photoanode material for photoelectrochemical water splitting. However, the poor photoinduced electron-hole separation efficiency limits its application. Herein, we report an effective strategy to suppress electron-hole recombination by introducing oxygen vacancies (OV) on the surface of a WO3 photoanode through NaH2PO2 treatment. An OV-enriched amorphous surface layer with a thickness of 4 nm is formed after NaH2PO2 treatment, which increases the charge carrier density and enlarges the electrochemical surface area of the photoanode. The charge separation and surface injection efficiencies are both improved after NaH2PO2 treatment, and the charge transfer process of the photoanode is accelerated consequently. The current density of the modified WO3 photoanode reaches 0.96 mA cm-2 at 1.23 V.

Green Engineered CuO/SnO2/HNT Composites: Illuminating the Photocatalytic Path for Organic Pollutant Remediation and Zebrafish Embryo Toxicity Evaluation.

Photocatalysis stands out as a promising technique for treating organic contaminants, yet the quest for visible light active composite materials, crafted through cost-effective, eco-friendly, and uncomplicated processes, poses formidable challenges. Here, we introduce a successful endeavor, the synthesis of a CuO/SnO2 (CS) composite via a microwave method, employing Carissa edulis fruit extract as a reducing as well as capping agent. Various loadings of CS-HNT composites were prepared by ultrasonically incorporating CS onto nanotubular halloysite (HNT) clay. Employing a suite of types of characterization, including XRD, XPS, FT-IR, FE-SEM, HR-TEM, ζ potential, UV-vis-DRS, TGA, BET, and EIS, we meticulously explored the morphology, structure, stability, surface area, electrochemical, and optical properties of the developed CS-HNT composites. HR-TEM observations unveiled the formation of a heterojunction between cubic CuO and spherical SnO2 on the HNT clay surface. Optical and EIS analysis highlighted that the 20CS-HNT composite displayed significant absorption in the visible region, efficient electron-hole pair separation, and enhanced interfacial charge transport relative to other loadings. Photocatalytic evaluations and optimization studies revealed that the 20CS-HNT photocatalyst achieved notable removal efficiencies, eliminating 85% of Congo red (CR) and 80% of tetracycline (TC) within 90 min and 74% of ATZ in 3 h under visible light conditions. Scavenging investigations, the fluorescence probe method, and a NBT transformation study underscored the pivotal roles of hydroxyl and superoxide radicals in pollutant removal. The reusability trials highlighted the exceptional stability and recyclability of the photocatalyst, even after five cycles. In addition, zebrafish embryo toxicity tests revealed improved survival and hatching rates in photocatalyst-treated samples compared to those of controls. Moderate toxicity was observed in treated TC, while the treated CR sample showed non-lethal toxicity. In essence, this study unveils a straightforward and efficacious approach for developing photocatalysts for large-scale wastewater treatment. Furthermore, it proposes the adoption of safe clay-based bimetal oxide photocatalysts in diverse environmental applications.

Synthesis of ZnPc/BiVO4 Z-Scheme Heterojunction for Enhanced Photocatalytic Degradation of Tetracycline Under Visible Light Irradiation

The construction of semiconductor heterojunctions is an effective strategy to improve the photocatalytic degradation efficiency of organic pollutants. Herein, ZnPc/BiVO4 Z-scheme heterojunction was synthesized via a physical mixing method and was used for the photocatalytic degradation of tetracycline (TC) under visible light irradiation. Compared with BiVO4 and ZnPc, the 15ZnPc/BiVO4 sample exhibited improved light absorption capacity, and the electron-hole separation efficiency and redox capacity were enhanced due to the formation of the Z-scheme heterojunction. The 15ZnPc/BiVO4 composite exhibited an optimal TC degradation rate of 83.1% within 120 min. Additionally, 15ZnPc/BiVO4 exhibited excellent stability in cycling experiments, which maintained a high TC degradation rate of 79.5% after four cycles. Free radical trapping experiments indicated that superoxide radicals (O2−) were the main active substances in the photocatalytic degradation of TC.

Synergistic photocatalytic degradation of TC-HCl by MIL-53(Fe)/CoWO4 composite and PMS under visible light

A series of novel MIL-53(Fe)/CoWO4 composites were synthesized by combining MIL-53(Fe) and CoWO4 nanoparticles via solvothermal method. The structural characterizations showed that CoWO4 nanoparticles were uniformly distributed on the surface of hexagonal bipyramid MIL-53(Fe). Combining XPS and Mott-Schottky plots, a Z-scheme heterojunction was formed between MIL-53(Fe) and CoWO4, resulting in a significant improvement in the electron-hole pair separation efficiency. UV–vis diffused reflectance spectra indicated that the optical arrange of MIL-53(Fe)/CoWO4 composites were expanded to visible light. The photocatalytic degradation experiments under visible light irradiation showed that MIL/CWO-60 synergistically with PMS degraded 90.5 % of TC-HCl within 50 min. The XRD spectra of used and unused composites were identical, indicating good stability in four consecutive cycles. Electron paramagnetic resonance (EPR) and free radicals trapping experiment revealed that active species included O2−, SO4−, h+, OH and 1O2, and mechanism of the synergistic degradation of TC-HCl by MIL-53(Fe)/CoWO4 composites and PMS was proposed.

Self-powered γ-In2Se3/p-Si heterojunction for photodetection: exploring humidity and light intensity dependent photoresponse

In this study, high-quality γ-In2Se3 thin films were successfully deposited on p-Si substrates via the RF sputtering technique. Structural characterization using XRD and Raman spectroscopy confirmed the formation of the hexagonal γ-phase of In2Se3 film. FESEM analysis revealed the presence of small, homogeneous, and well-defined grains in the prepared γ-In2Se3 film. EDS analysis confirmed the stoichiometric composition (∼ 2:3) of the In2Se3 films. XPS further validated the presence of In, Se, and Si elements in the deposited films. Band gap analysis using UV-visible spectroscopy yielded a value of 1.96 eV for the γ-In2Se3 film. Integration of γ-In2Se3 with p-type Si enhanced photoresponsivity of 47.9 mA/W, photosensitivity of 282, and photo detectivity of 8.45 × 1010 Jones. The self-powered γ-In2Se3/p-Si heterojunction-based photodetector exhibited rapid rise time attributed to the type II band alignment structure, facilitating efficient electron-hole pair separation and minimizing recombination. Furthermore, humidity and light intensity-dependent photodetector properties of γ-In2Se3/p-Si heterojunction photodetector were also investigated. An increase in photocurrent from 271 to 291 µA was observed with rising humidity levels, indicating the device’s sensitivity to humidity variations. Furthermore, light intensity dependence studies revealed a linear relationship between photocurrent and incident light intensity, demonstrating the device’s reliable response across various illumination levels.

Microwave-Assisted Synthesis of CdS-MOF MIL-101 (Fe) Composite: Characterization and Photocatalytic Performance.

The present study outlines the synthesis of cadmium sulfide-metal-organic framework (CdS-MOF) MIL-101 (Fe) heterojunctions achieved via fast microwave-assisted reactions. Thus, different CdS-MOF MIL-101 (Fe) ratios were prepared to study their effectiveness as photocatalysts. These compounds were employed in the photocatalytic degradation of methylene blue (MB) under UV and visible irradiation. Structural, morphological, textural, compositional, and optical properties of the synthesized compounds determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy were utilized to characterize the structural, morphological, textural, compositional, and optical properties. Electrochemical impedance spectroscopy (EIS) was also employed to determine photovoltage and photocurrent densities. The resulting valence band offset (Vfb) and band gap energy values were utilized to construct an energy band scheme. Our research revealed that the CdS-MOF MIL-101 (Fe) heterojunction enhances the efficiency of electron-hole pair separation, thereby mitigating charge carrier recombination effects. Moreover, the type I electronic band structure established an efficient reaction mechanism, effectively suppressing the recombination of photogenerated electron-hole pairs. The photocatalytic system demonstrated exceptional behavior, achieving complete MB removal within 30 min of reaction time and exhibiting outstanding stability and reusability after four reaction cycles. These findings highlight the potential of the synthesized compounds in the field of wastewater treatment for organic pollutants, offering a promising alternative to current environmental issues.

Water/oil interfacial photocatalysis of amphiphilic CdS/Bi2WO6 S-scheme heterojunctions for efficient production and spontaneous separation of H2O2 and value-added organics

The photocatalytic co-production of H2O2 and value-added organics in a suitable water/oil biphasic system offers an intriguing strategy to address the challenges encountered in a single liquid-phase solution, including the efficient separation of H2O2 and organic products as well as the mitigation of undesirable secondary reactions. For this, exploring amphiphilic photocatalysts with high performance is highly required. Herein, an amphiphilic CdS/Bi2WO6 S-scheme heterojunction photocatalyst is designedly synthesized through a two-step solvothermal process, aiming to achieve efficient interfacial photocatalytic reactions at the water/oil interface for simultaneous generation and selective separation of H2O2 and organic products. The CdS/Bi2WO6 heterojunction photocatalyst exhibits enhanced light absorption in UV–visible region, increased electron-hole separation efficiency, and powerful charge carriers with high redox abilities. Moreover, the formation of S-scheme heterojunction improves the catalyst stability by preventing CdS from photocorrosion. As a result, the production rate of H2O2 reaches up to 216.76 mmol g−1 h−1, accompanied by the generation of organic products (benzaldehyde: 104.91 mmol g−1 h−1, benzoic acid: 49.88 mmol g−1 h−1, and benzyl benzoate: 38.01 mmol g−1 h−1), in a water/benzyl-alcohol biphasic system under simulated sunlight irradiation. The photocatalytic mechanism is elucidated based on the results of comprehensive experiments and characterizations. This study highlights a rational construction of amphiphilic photocatalysts and their application in organic/water interfacial photocatalytic reactions.

Interface-engineered Ni(Fe/Al)-LDHs/g-C3N4 nanosheets with metallic Fe/Al[sbnd]N bonds for efficient photocatalytic degradation of tetracycline hydrochloride

To improve the photogenerated electron–hole separation efficiency and the number of reactive oxygen species of g-C3N4 in visible light. Herein, an interface-engineered Ni(Fe/Al)-LDHs/g-C3N4 nanosheets with Fe/AlN bonds were prepared, which shows highly enhanced photocatalytic degradation performance with excellent structural stability. The interfacial structure of g-C3N4 was precisely regulated by metal Fe/Al on the surface of layered double hydroxides (LDHs), which could form Fe/AlN bonds as the interfacial charge transfer channels. In addition, the metal Ni and Fe/Al on the surface of LDHs nanosheets can furnish more photocatalytic active sites and interface synergy. The obtained 7 %NiFe-LDHs/g-C3N4 owns the degradation rate of 99.23 % for tetracycline hydrochloride (TCH) in visible light. This work highlights a rational interface engineering strategy for the formation of a composite structure with interface interaction for efficient photocatalysts.

Constructing a Z-scheme heterojunction of oxygen-deficient WO3-x and g-C3N4 for superior photocatalytic evolution of H2

Semiconductor-based photocatalytic water splitting enables the conversion of abundant solar energy to green and renewable hydrogen energy. Graphitic carbon nitride (g-C3N4) is synthesized using a straightforward method, demonstrating stable physicochemical properties and possessing an optimal bandgap, thus positioning it as a promising photocatalyst in the realm of environmental sustainability. Oxygen vacancies are extensively employed to modulate light absorption and surface properties of metal-oxide semiconductors. In this study, g-C3N4 nanosheets were coupled with oxygen-deficient tungsten trioxide (WO3-x) to form heterojunction photocatalysts (X-WOCN). Comprehensive material characterization results demonstrated that the constructed heterojunction extended the visible light absorption range, improved photogenerated electron-hole separation efficiency, and thus augmented photocatalytic activity. Notably, the optimum hydrogen evolution rate of 6%-WOCN was enhanced by 5.4-fold compared to that of g-C3N4. Furthermore, we propose a Z-scheme heterojunction charge separation mechanism mediated by oxygen defects and support this mechanism through detection of surface-active substances •O2− and •OH. This study offers novel propositions into the function of oxygen defects in facilitating charge separation within Z-scheme heterojunction.

Construction of SnO2/Cu2O heterojunctions for enhanced photocatalytic degradation of moxifloxacin

Herein, SnO2/Cu2O heterojunction composites were prepared using a hydrothermal method for moxifloxacin removal from water. Cu2O and SnO2 were detected in the composite samples, which exhibited between the two semiconductors. The introduction of SnO2 into pure Cu2O, forming a heterojunction structure, can enhance device charge conversion, improve photocurrent intensity and photogenerated electron-hole separation efficiency, and greatly improve photocatalytic performance. Moxifloxacin degradation by SnO2/Cu2O composites reached 86.4 %. The proposed catalytic mechanism was based on radical scavenging, with • O2‐ identified as the main active species. In addition, the moxifloxacin degradation intermediates were analyzed, with possible degradation pathways suggested.

Visible light assisted periodate activation with porous C3N5 for tetracycline degradation: Enhanced electron-hole separation and reactive oxygen species formation

In this study, porous C3N5 (p-C3N5) was synthesized to activate periodate (PI) for tetracycline (TC) degradation under visible light condition. Experimental results confirmed that the porous structure in C3N5 created abundant defects as active sites, which not only increased the photoelectricity and electron-hole separation efficiency, but also promoted PI activation and reactive oxygen species formation, achieving significantly improved PI-assisted photocatalytic performance. In detail, p-C3N5 exhibited high photocurrent density which was 12.7 and 28.9 times as much as those of g-C3N5 and g-C3N4 respectively. Moreover, the p-C3N5/PI/vis system can achieve 80% TC removal rate within 10 min via ∙O2-, 1O2, IO3∙, ∙OH, h+ and electron transfer pathways. Furthermore, this system could maintain stable degradation capacity under a wide pH range, with less interference by inorganic anions, demonstrating its high reusability, robustness and environmental friendliness. Six possible degradation pathways of TC were proposed based on the detection of intermediate products and density functional theory calculation. Finally, the toxicity assessment showed a significantly reduction of TC bio-toxicity after treatment by p-C3N5/PI/vis system, and no formation of iodine by-products. It provides a deep insight into designing high efficiency and environmentally photocatalysts for activating PI to treat the antibiotic wastewater.

Microenvironment modulation of Fe-porphyrinic metal–organic frameworks for CO2 photoreduction

Photocatalytic CO2 reduction to fuels and chemicals is a promising pathway towards carbon resource recovery. Herein, three isomorphic Fe-porphyrinic MOFs, Zr6O4(OH)4(Fe-TCPP)3 (MOF-525, Fe-TCPP = iron 5,10,15,20-tetra(4-carboxyphenyl)-porphyrin), Zr6O4(OH)4(Fe-TCPP-NO2)3 (MOF-525-NO2, Fe-TCPP-NO2 = iron 5,10,15,20-tetra(2-nitro-4-carboxyphenyl)-porphyrin), and Zr6O4(OH)4(Fe-TCBPP-NO2)3 (MOF-526-NO2, Fe-TCBPP-NO2 = iron 5,10,15,20-tetra[4-(4′-carboxyphenyl)-2-nitrophenyl]-porphyrin) were synthesized and employed as photocatalysts for CO2 reduction. Among them, MOF-525-NO2 exhibited the highest catalytic activity with CO and H2 yields of 10.36 and 0.46 mmol·g−1 without any photosensitizer under visible light. Mechanism investigations suggested that the micro-environments of these MOFs were adjusted by introducing porphyrinic fragments with different lengths and functional groups, resulting in stronger CO2 affinity, faster photocurrent response, and efficient photogenerated electron-hole separation and transfer, which finally promoted the efficiency for photocatalytic CO2 reduction.

Unprecedented Photocatalytic Hydrogen Peroxide Production via Covalent Triazine Frameworks Constructed from Fused Building Blocks.

Covalent organic frameworks (COFs) have garnered attention for their potential in photocatalytic hydrogen peroxide (H2O2) production. However, their photocatalytic efficiency is impeded by insufficient exciton dissociation and charge carrier transport. Constructing COFs with superior planarity is an effective way to enhance the π-conjugation degree and facilitate electron-hole separation. Nonetheless, the conventional linear linkers of COFs inevitably introduce torsional strain that disrupts coplanarity.Herein, we address this issue by introducing inherently coplanar triazine rings as linkers and fused building blocks as monomers to create covalent triazine frameworks (fused CTFs) with superior coplanarity. Both experimental and theoretical calculations confirm that CTFs constructed from fused building blocks significantly enhance the electron-hole separation efficiency and improve the photocatalytic performance, compared to the CTFs constructed with non-fused building blocks. The frontier molecular orbitals and electrostatic potentials (ESP) revealed that the ORR is preferentially facilitated by the triazine rings, with the WOR likely occurring at the thiophene-containing moiety. Remarkably, CTF-BTT achieved an exceptional H2O2 production rate of 74956 μmol g-1 h-1 when employing 10% benzyl alcohol (V/V) as a sacrificial agent in an O2-saturated atmosphere, surpassing existing photocatalysts by nearly an order of magnitude.

The n-MoO3/p-Si heterojunction photodiode: Influence of the MoO3 film thickness on the ultraviolet and infrared photodetector performance

Here, we studied the effect of the MoO3 thin film thickness on the ultraviolet (UV) and infrared (IR) photodiode properties of the n-MoO3/p-Si heterojunction structure. Initially, the metal molybdenum (Mo) thin films with different thicknesses (50,150, and 250 nm) were created via DC magnetron sputtering on a p-type Si substrate. Then, the MoO3 thin films were synthesized using a thermal oxidation method with an optimal oxygen flow rate of 60sccm. XRD and Raman analysis showed that the structure of prepared thin films has converted from an amorphous to an orthorhombic (α-MoO3) crystalline phase with increasing thickness. The optical transmittance of the layers was tuned by controlling the thickness, and the maximum transmittance for the 50 nm-thick film was achieved in the broad wavelength range of 300–1100 nm. The current density–voltage (J–V) characteristics indicate the prepared samples' rectifying behavior under dark conditions. The heterojunction photodiode with a 50 nm-thick MoO3 layer shows the best performance. This sample had a maximum amount of transmittance in the UV–visible and IR regions, compared to other samples, which leads to efficient electron-hole separation and transportation. This sample demonstrates a significant photoresponse ratio (ILight/IDark) of about 55 and 52.5 in the ultraviolet (UV) and infrared (IR) regions, respectively.

1D Lead Bromide Hybrids Directed by Complex Cations: Syntheses, Structures, Optical and Photocatalytic Properties.

This study presents the synthesis, structural characterization, and evaluation of the photocatalytic performance of two novel one-dimensional (1D) lead(II) bromide hybrids, [Co(2,2'-bpy)3][Pb2Br6CH3OH] (1) and [Fe(2,2'-bpy)3][Pb2Br6] (2), synthesized via solvothermal reactions. These compounds incorporate transition metal complex cations as structural directors, contributing to the unique photophysical and photocatalytic properties of the resulting materials. Single-crystal X-ray diffraction analysis reveals that both compounds crystallize in monoclinic space groups with distinct 1D lead bromide chain configurations influenced by the nature of the complex cations. Optical property assessments show band gaps of 3.04 eV and 2.02 eV for compounds 1 and 2, respectively, indicating their potential for visible light absorption. Photocurrent measurements indicate a significantly higher electron-hole separation efficiency in compound 2, correlated with its narrower band gap. Additionally, photocatalytic evaluations demonstrate that while both compounds degrade organic dyes effectively, compound 2 also exhibits notable hydrogen evolution activity under visible light, a property not observed in 1. These findings highlight the role of metal complex cations in tuning the electronic and structural properties of lead(II) bromide hybrids, enhancing their applicability in photocatalytic and optoelectronic devices.

Unveiling the Synergistic Role of Ferroelectric Polarization and Z‐Scheme Heterojunction in Bi2Fe4O9/Carbon‐Deficient g‐C3N4 for Enhanced Methylene Blue Degradation Efficiency

ABSTRACTEnhancing the efficiency of charge carrier separation is crucial for improving the performance of photocatalysts, thereby offering more effective solutions to energy and environmental pollution challenges. In this study, a carbon‐deficient ultra‐thin porous g‐C3N4 (Vc‐UPCN) was synthesized and subsequently was integrated with Bi2Fe4O9 (BFO) using a sonochemical self‐assembly technique, a Bi2Fe4O9/Vc‐UPCN (BC) photocatalyst featuring a Z‐scheme heterojunction. The BC catalyst was subjected to corona poling treatment to obtain BCp, which possesses an intrinsic electric field. Compared with pure BFO and Vc‐UPCN, the BC heterojunction exhibited higher photo‐generated electron–hole separation efficiency and photodegradation ability. Upon introduction of corona polarization, the photocatalytic performance of BC was further enhanced. Specifically, BCp‐15 (BFO/BC mass fraction = 15) achieved complete degradation of methylene blue (MB) within 30 min. BCp‐15 demonstrated that its degradation efficiency for MB was 1.28 times higher than that of BC‐15, 1.85 times higher than that of Vc‐UPCN, and impressive 7.69 times higher than that of pure BFO. The coupling effect of the heterojunction and ferroelectric polarization significantly improved the separation efficiency of photo‐generated carriers in BCp. This study is expected to provide a reference for the synergistic application of heterojunction and ferroelectric polarization in traditional semiconductor photocatalysis.