Efficient Charge Separation Research Articles

Simulation of electron and nuclear spin dynamics in many-spin charge-separated states.

This study presents a numerical simulation approach to investigate singlet-triplet interconversion effects in organic materials with rigid molecular structures that facilitate the photogeneration of charge-separated (CS) states, such as zwitterions resulting from intramolecular electron transfer. Our approach enables the detailed modeling of electron and nuclear spin-dependent observables, including magnetic field-affected reaction yields (MARY) and chemically induced dynamic nuclear polarization (CIDNP). The equilibrium solution of the stochastic Liouville equation can be obtained with simple algebraic manipulation by noting the relationship between the Laplace transform of the density operator and the time-domain representation of the same operator. Experimental MARY and CIDNP data are modeled as functions of key external and internal system parameters, such as magnetic field strength, hyperfine interactions, and exchange couplings. This allows for exploring processes that are otherwise experimentally inaccessible, providing deeper insights into the spin dynamics of the photoinduced CS state. Understanding these interconversion processes is not only essential for the fundamental photochemistry studies but also for the rational design and development of novel organic materials for photovoltaics and photocatalysis. Our results demonstrate the significant impact of singlet-triplet interconversion on the overall efficiency of charge separation and recombination processes, highlighting the importance of spin dynamics in the design of next-generation organic photovoltaic materials.

Enhanced Photoelectrochemical Performance by Constructing CdS/CdSe Heterojunction Structure

The growing need for sustainable energy development has become a critical issue due to worsening environmental pollution and climate change. Among the various technologies, the photoelectrochemical technology has been recognized as one of the essential approaches for advancing sustainable energy production. Out of the semiconductor materials used in PEC systems, cadmium sulfide (CdS) and cadmium selenide (CdSe) have been widely studied as promising candidates due to their advantageous properties. CdS, with a bandgap of 2.4 eV and high photoactivity, and CdSe, with a narrower bandgap of 1.9 eV and excellent light absorption characteristics, offer complementary advantages. In this study, we synthesized the CdS and CdSe materials via hydrothermal and chemical bath deposition methods, respectively, to fabricate a CdS/CdSe heterojunction photoanode system. The heterojunction CdS/CdSe photoanode formed a type-II structure, which facilitated efficient charge separation and transfer. Moreover, the CdS/CdSe photoanode exhibited high light absorption properties with very low charge transfer resistance, attributed to the role of CdS particles beneath CdSe as an electron transfer layer and the porous structure of the composite material. As a result, the CdS/CdSe photoanode achieved high photocurrent density of 4.51 mA·cm<sup>-2</sup> comparing to their individual cases, representing a 78% improvement in PEC performance compared to the only CdSe photoanode case.

Sulfur Vacancy-Induced Enhancement of Piezocatalytic H2 Production in MoS2.

This study explores the role of S vacancies in MoS2 in enhancing its piezocatalytic efficiency. Sulfur vacancies in the crystal lattice introduce localized changes in the electronic structure and charge distribution, improving the material's piezoelectric response. Characterization of the catalysts involved techniques like field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements, including impedance spectroscopy (EIS) and Mott-Schottky (M-S) analysis, are performed to assess the piezocatalytic performance. The study also employed density functional theory (DFT) calculations to investigate the electronic structure and hydrogen adsorption properties of MoS2 with S vacancies. The results demonstrated that S-deficient MoS2 significantly enhanced piezocatalytic H2 evolution. The piezocatalytic H2 production rates of MoS2 with different vacancy concentrations are measured under ultrasonic vibration. The sample with an optimal vacancy concentration (MS-1) exhibited the highest H2 production rate of 1423.29µmol g-1 h-1, compared to 439.06µmol g-1 h-1 for pristine MoS2 (MS-0). The improved performance is attributed to the increased piezoelectric polarization and efficient charge separation facilitated by S vacancies.

Unequal {110} Facets: The Potential Role of Intraparticle Heterogeneity and Facet Termination in Photoelectrochemical Activity of Single BiVO4 Particles.

BiVO4 photoanodes are promising for solar water splitting, with photogenerated electrons and holes preferentially reacting at top {010} and lateral {110} facets, respectively. However, the mechanisms driving this facet-dependent reactivity remain unclear. Here, we investigate facet-dependent photocurrent and material heterogeneity using correlative scanning photoelectrochemical microscopy (SPCM), electron beam induced current (EBIC) mapping, and mid-IR scattering scanning near-field optical microscopy (s-SNOM). SPCM measurements of 62 BiVO4 particles confirmed higher photocurrents at lateral {110} facets compared to top {010} facets, but unexpectedly revealed variations in photocurrent among lateral facets within the same particle. Variations in lateral facet surface termination could explain the intraparticle-level reactivity heterogeneity, consistent with theoretical predictions. Nano-FTIR spectroscopy and Raman microspectroscopy indicated significant materials chemistry heterogeneity within individual particles and facets that could be attributed to variations in lattice vibration distortions that enhance the overlap between Bi 6s and O 2p orbitals. The increased orbital overlap is significant as it potentially increases hole mobility in the valence band and potentially explains the lateral facet-dependent charge separation efficiency observed in photocurrent maps. Facet-dependent electrical and EBIC measurements showed no space charge regions at interfacet junctions or metal-BiVO4 contacts under vacuum, suggesting that photogenerated holes beneath top {010} facets are unlikely to transport to lateral {110} facets to drive water/sulfite oxidation. These findings indicate the potential influence of distinct bulk properties and surface termination chemistries across different particles and facets, highlighting the importance of carefully controlling defects and surface chemistry during sample growth to optimize photocatalytic performance.

Novel Fullerene-Based Dyes for Solar Cells Applications: Insights from Density Functional Theory and Time Dependent Density Functional Theory Investigations

Fullerene-based organic dyes hold significant promise for advancingsolar cell technologies due to their exceptional optoelectronic properties. This study investigates two novel fullerene-based dyes, Fullerene Dye 1 and Fullerene Dye 2 (FD1 and FD2), using Density Functional Theory (DFT)and Time-Dependent Density Functional Theory(TD-DFT)to evaluate their potential for solar cell applications. The electronic properties, including the Highest Occupied Molecular Orbital (HOMO), Lowest Unoccupied Molecular Orbital (LUMO), and HOMO-LUMO (H-L) energy gaps, were analyzed using the B3LYP functional with a 6-31G basis set, incorporating solvation effects with dichloromethane (DCM) in the Polarizable Continuum Model (PCM). FD1 exhibited a HOMO of -5.123 eV, a LUMO of -3.458 eV, and an H-L gap of 1.665 eV, while FD2 showed a slightly larger gap of 1.807 eV with a HOMO of -5.261 eV and a LUMO of -3.454 eV. Time-dependent DFT analysis revealed maximum absorption wavelengths (𝜆max) of 997.10 nm and 995.16 nm for FD1 and FD2, respectively, with corresponding oscillator strengths of 0.0075 and 0.0048. The light-harvesting efficiencies, LHEs of FD1 and FD2 were 0.018 and 0.012, respectively. Both dyes demonstrated favorable reorganization energy, 𝜆=0.15eV, driving force for charge injection, Δ𝐺inj= 0.542eV for FD1 and 0.546 eV for FD2, and low driving force for charge recombination (Δ𝐺CR), indicating strong potential for efficient charge separation. These findings provide valuable insights into the electronic, optical, and charge transfer properties of fullerene-based dyes, with FD1 exhibiting a more balanced performance. The study highlights the potential of these dyes for enhancing the efficiencies of organic, dye-sensitized solar cells (DSSCs) and provides a foundation for future experimental validation and optimization.

Surface Nd Sites Boost Charge Transfer of Fe2O3 Photoanodes for Enhanced Solar Water Oxidation.

Photoelectrochemical (PEC) water splitting for hydrogen production is a promising technology for sustainable energy generation. In this work, we introduce Nd sites boost the PEC performance of Fe2O3 photoanodes through a precise gas-phase cation exchange process, which substitutes surface Fe atoms with Nd. The incorporation of Nd significantly enhances charge transfer properties, increases carrier concentration, and reduces internal resistance, leading to a substantial increase in photocurrent density from 0.44 to 0.92 mA cm-2 at 1.23 VRHE. Further enhancement of catalytic activity was achieved by depositing a NiCo(OH)x layer and a photocurrent density of 1.15 mA cm-2 at 1.23 VRHE were obtained. Theoretical calculations corroborate these experimental results, revealing that Nd doping narrows the bandgap, improves charge separation efficiency, and lowers the reaction potential barrier, thereby accelerating water oxidation kinetics. These findings underscore the effectiveness of surface cation exchange and targeted metallic element doping in overcoming the intrinsic limitations of Fe2O3, providing a viable pathway for developing high-performance PEC systems for efficient hydrogen production.

Hybrid of CdS/ZIF-11 with highly efficient charge separation for photocatalytic degradation of Tetracycline: fabrication, catalytic optimization, physicochemical studies

ABSTRACT A zeolitic imidazolate framework and cadmium sulphide hybrid (CdS/ZIF-11, CdS: 14, 32, 50, 68 mg) were created for the first time, and its efficacy as a photocatalyst for Tetracycline (TC) degradation was examined. XRD, FTIR, DRS, PL, FESEM, EDS, BET, and EIS were used to characterise the synthetic materials. The distinct peaks of ZIF-11 and CdS were found in the XRD patterns of composites at 4.37º and 26.85º, respectively. However, the combination CdS(68)/ZIF-11 did not produce any ZIF-11 structure. FESEM images of composites showed that the RHO morphology of ZIF-11 was evident and that the ZIF-11 surface was coated with CdS nanoparticles. Their relative band gaps were found to be 4.05, 1.83, (2.32 and 3.67), (2.05 and 3.8)eV for CdS, ZIF-11, CdS(32)/ZIF-11, and CdS(50)/ZIF-11. ZIF-11, CdS(32)/ZIF-11, and CdS(50)/ZIF-11 samples were found to have surface areas of 219.02, 30.965, and 186.23 m2/g, respectively. The electron/hole recombination in the CdS(32)/ZIF-11 nanostructure was lower than in ZIF-11, per PL and EIS studies. The photocatalytic degradation efficiency of 20 ppm TC solution, pH = 7, under visible light using 0.1 g/L of CdS(32)/ZIF-11 was three times higher than that of other composites. Therefore, this composite was selected as the best sample and the degradation operating parameters were optimised using it. The optimal photocatalyst concentration under visible light irradiation by CdS(32)/ZIF-11, was determined to be (0.55 mg/L or 0.11 g), pH = 5 and the TC concentration was (40 mg/L or 0.008 g), resulting in a maximum efficiency of 79.2%. TC (40 ppm) degrades with a first order rate constant equal to 0.016 min−1. The CdS(32)/ZIF-11 sample was suggested to be subject to the Z-scheme mechanism. For three successive cycles, the aforementioned sample exhibited satisfactory stability. All things considered, the CdS/ZIF-11 combination may find impressive uses in pollution treatment.

Construction of a thiophene-based conjugated polymer/TP-PCN S-scheme to enhance visible-light-driven photocatalytic activity: Promotion of wound healing in super-resistant bacterial infections.

S-scheme heterojunctions have garnered significant attention in the field of photocatalytic antimicrobials due to their superior charge separation efficiency and higher redox capacity. In this study, an innovative linear conjugated polymer (PCO) was combined with fragmented carbon nitride (TP-PCN) to create PCO/TP-PCN organic-organic S-scheme heterojunctions, which markedly enhanced the photocatalytic antimicrobial performance. The composite (PCO-7/TP-PCN) demonstrated the ability to combat bacterial infections under visible light irradiation, effectively eradicating approximately 2.16 × 107 cfu/ml MRSA within 6 min. This exceptional photocatalytic performance can be attributed to the successful formation of an S-scheme heterojunction between PCO and TP-PCN, as well as the interaction of surface functional groups of PCO-7/TP-PCN with bacteria. Results from UV-Vis-NIR DRS and in situ-XPS experiments indicated a significant enhancement in carrier transport rate through the establishment of a built-in electric field and energy band bending at the interface. In vitro and in vivo experiments further demonstrated that PCO-7/TP-PCN not only exhibited potent antimicrobial activity under visible light irradiation but also promoted angiogenesis to inhibit inflammatory responses. Therefore, it can be concluded that this organic-organic S-scheme heterojunction photocatalyst holds great potential for development as a promising new generation of efficient antimicrobial materials, which could aid in preventing bacterial infection of wounds and ensuring effective wound healing.

Synergistic modification of Cu3V2O8 nanosheeta photoelectrodes with NiFe and NiOx for efficient and ultra‐stable photoelectrochemical water oxidation

AbstractBACKGROUNDThe design and development of environmentally friendly, efficient, and stable photoelectrodes are crucial for advancing photoelectrochemical (PEC) water‐splitting technology.RESULTSIn this study, we report a novel strategy for the preparation of copper vanadate (Cu3V2O8) nanosheet arrays using a low‐temperature solution method. Notably, this is the first instance of directly growing Cu3V2O8 nanosheet arrays on FTO (fluorine‐doped tin oxide) conductive glass. The morphology of the developed nanosheet arrays offers a larger specific surface area and improved bulk charge separation efficiency, which are desirable characteristics for PEC water‐splitting applications. To further enhance the stability and PEC performance of the Cu3V2O8 nanosheets, a synergistic modification strategy was employed. This approach involved the deposition of an NiOx passivation layer and the incorporation of an NiFe co‐catalyst. The synergistic modification strategy significantly improved the PEC performance and stability of the Cu3V2O8 nanosheet arrays. The modified photoelectrode achieved an impressive photocurrent of 0.67 mA cm−2 at 1.23 V versus a reversible hydrogen electrode and demonstrated stability for over 80 h of operation.CONCLUSIONThis work provides a new, low‐cost, and effective strategy for the preparation of efficient and stable photoelectrodes for PEC water splitting, which is a crucial step towards the development of environmentally friendly and sustainable energy technologies. © 2025 Society of Chemical Industry (SCI).

Enhancement of the photoelectrochemical performance of bismuth vanadate (BiVO4) photoanode by building a W:BiVO4/Mo:BiVO4 Homojunction

AbstractWe fabricated a highly efficient bismuth vanadate (BiVO4)‐based photoanode by constructing a W:BiVO4/Mo:BiVO4 homojunction configuration. It was confirmed that, in the case of Type‐II junction, the photocurrent density was drastically enhanced and the onset potential was cathodically shifted. The origins of the enhanced photo‐electrochemical performance could be attributed to the improvement of the charge separation efficiency, which resulted from both the built‐in electric field and Fermi level unpinning, achieved by the homojunction and Mo doping, respectively.

Flexible Room‐Temperature Ammonia Sensor Using Multi‐Heterojunction MoO3/CuO/Cu2O Nanoclusters for Noninvasive Kidney Disease Diagnosis

In this study, a flexible room‐temperature ammonia (NH3) sensor is developed based on MoO3/CuO/Cu2O hybrid nanoclusters (HNCs), specifically designed for the noninvasive diagnosis of nephropathy. The MoO3/CuO/Cu2O HNCs achieve an ultralow detection limit of 0.73 ppm, with high sensitivity (0.163 ppm−1) and rapid response and recovery times (16.4 and 90.6 s). The integration of MoO3 (n‐type) with CuO and Cu2O (p‐type) forms multi‐heterojunctions, enhancing gas‐sensing performance through efficient charge separation and improved NH3 adsorption. Additionally, the sensor demonstrates excellent mechanical flexibility and long‐term stability under dynamic deformation. To address humidity interference in exhaled breath analysis, the sensor with a hydrophobic polytetrafluoroethylene layer is coated via radio frequency sputtering, ensuring effective NH3 detection and differentiation between healthy individuals and kidney disease patients. In this work, the potential of multi‐heterojunction nanostructures in developing high‐performance, flexible gas sensors for practical health‐monitoring applications is highlighted.

Surface Bi-vacancy and corona polarization engineered nanosheets with sonopiezocatalytic antibacterial activity for wound healing.

Piezocatalytic therapy is an emerging therapeutic strategy for eradicating drug-resistant bacteria, but suffers from insufficient piezoelectricity and catalytic active site availability. Herein, Bi-vacancies (BiV) and corona polarization were introduced to BiOBr nanosheets to create a BiOBr-BiVP nanoplatform for piezocatalytic antibacterial therapy. This meticulously tailored strategy strengthens the built-in electric field of nanosheets, enhancing piezoelectric potential and charge density and boosting charge separation and migration efficiency. Meanwhile, BiV adeptly adjust the band structure and increase reaction sites. Ultrasonication of nanosheets continuously enables the generation of reactive oxygen species (ROS) and CO, facilitating almost 100% broad-spectrum antibacterial efficacy. BiOBr-BiVP nanosheets demonstrate full bacterial eradication and accelerate wound healing through simultaneous regulation of inflammatory factors, facilitation of collagen deposition, and promotion of angiogenesis. Overall, this ultrasonic-triggered piezocatalytic nanoplatform combines BiV and the corona polarization strategy, providing a robust strategy for amplifying piezocatalytic mediated ROS/CO generation for drug-resistant bacterial eradication.

Harvesting ionic power from a neutralization reaction through a heterogeneous graphene oxide membrane.

Nanofluidics is a system of fluid transport limited to a nano-confined space, including the transport of ions and molecules. The use of intelligent nanofluidics has shown great potential in energy conversion. However, ion transport is hindered by homogeneous membranes with uniform charge distribution and concentration polarization, which often leads to an undesirable power conversion performance. Here, we demonstrate the feasibility of a neutralization reaction-enhanced energy conversion process based on heterogeneous graphene oxide (GO) nanofluidics with a bipolar structure. The asymmetric charge distribution inherent to the heterogeneous nanofluidics facilitates a complementary two-way ion diffusion process, which in turn promotes efficient charge separation and superposed ionic diffusion. An output power density of up to 29.58 W m-2 is achieved with 0.1 M HCl/NaOH as the acid-base pair (ABP), which is about 712% and 117% higher than using symmetric unipolar pGO and nGO membranes. Both experiments and theoretical simulations indicate that the tunable asymmetric heterostructure contributes to regulating diffusion-based ion transport and enhancing the ion flux. This work not only establishes a significant paradigm for the utilization of chemical reactions within nanofluidic systems but also opens up new avenues for ground-breaking discoveries in the fields of chemistry, nanotechnology, and materials science.

A Versatile Self‐Templating Approach for Constructing Ternary Halide Perovskite Heterojunctions to Achieve Concurrent Enhancement in Photocatalytic CO2 Reduction Activity and Stability

AbstractMetal halide perovskite (MHP)‐based photocatalysts encounter significant stability challenges in water‐containing systems, posing a major obstacle to their application in artificial photosynthesis. Herein, an innovative and universal strategy is present to create MHP‐based ternary heterojunctions based on a self‐templating method. A series of composite catalysts featuring sandwich hollow structures are constructed, with MHPs such as CsPbBr3, Cs3Bi2I9, Cs3Sb2Br9, and Cs2AgBiBr6 serving as the intermediate layers. The unique sandwich structure effectively shields MHPs from direct water contact, allowing MHP‐based photocatalysts to exhibit exceptional stability in water‐containing photocatalytic environments for durations exceeding 200 h. Furthermore, the hollow design ensures complete contact between the reaction substrates with both the oxidation and reduction functional areas. Compared to single perovskite materials, MHP‐based ternary heterojunction photocatalysts exhibit stronger oxidation capability and improved charge separation efficiency, leading to a substantial enhancement in photocatalytic CO2 reduction performance. Notably, the ternary heterojunction with CsPbBr3 as the intermediate layer achieves an electron consumption rate of up to 1824 µmol g−1 h−1 for CO2 reduction, which is far superior to other reported MHP‐based catalysts under similar conditions. This study provides a potent strategy for simultaneously enhancing the stability and activity of MHP‐based photocatalysts, paving the way for their potential applications in artificial photosynthesis.

Methane oxidation to ethanol by a molecular junction photocatalyst.

Methane, the major component of natural and shale gas, is a significant carbon source for chemical synthesis. The direct partial oxidation of methane to liquid oxygenates under mild conditions1-3 is an attractive pathway, but the molecule's inertness makes it challenging to achieve simultaneously high conversion and high selectivity towards a single target product. This difficulty is amplified when aiming for more valuable products that require C-C coupling4,5. While selective partial methane oxidation processes1-3,6-9 have thus typically generated C1 oxygenates6,7, recent reports have documented photocatalytic methane conversion to the C2 oxygenate ethanol with low conversions but good to high selectivities4,5,8-12. Here, we show that the intramolecular junction photocatalyst CTF-1 with alternating benzene and triazine motifs7,13 drives methane coupling and oxidation to ethanol with a high selectivity and much improved conversion. The heterojunction architecture not only enables efficient and long-lived separation of charges after their generation, but also preferential adsorption of H2O and O2 to the triazine and benzene units, respectively. This dual-site feature separates C-C coupling to form ethane intermediates from the sites where •OH radicals are formed and thereby avoids overoxidation. When loaded with Pt to boost performance further, the molecular heterojunction photocatalyst generates ethanol in a packed-bed flow reactor with improved conversion that results in an apparent quantum efficiency of 9.4%. We anticipate that further developing the "intramolecular junction" approach will deliver efficient and selective catalysts for C-C coupling, pertaining, but not limited, to methane conversion to C2+ chemicals.

Design and Preparation of ZnIn2S4/g-C3N4 Z-Scheme Heterojunction for Enhanced Photocatalytic CO2 Reduction

In this study, a novel Z-scheme heterojunction photocatalyst was developed by integrating g-C3N4 nanoplates into ZnIn2S4 microspheres. X-ray photoelectron spectroscopy analysis revealed a directional electron transfer from g-C3N4 to ZnIn2S4 upon heterojunction formation. Under irradiation, electrochemical tests and electron paramagnetic resonance spectroscopy demonstrated significantly enhanced charge generation and separation efficiencies in the ZnIn2S4/g-C3N4 composite, accompanied by reduced charge transfer resistance. In photocatalytic CO2 reduction, the ZnIn2S4/g-C3N4 composite achieved the highest CO yield, 1.92 and 5.83 times higher than those of pristine g-C3N4 and ZnIn2S4, respectively, with a notable CO selectivity of 91.3% compared to H2 (8.7%). The Z-scheme heterojunction mechanism, confirmed in this work, effectively preserved the strong redox capabilities of the photoinduced charge carriers, leading to superior photocatalytic performance and excellent long-term stability. This study offers valuable insights into the design and development of g-C3N4-based heterojunctions for efficient solar-driven CO2 reduction.

Enhanced Photocatalytic Efficiency Through Oxygen Vacancy-Driven Molecular Epitaxial Growth of Metal-Organic Frameworks on BiVO4.

Efficient charge separation at the semiconductor/cocatalyst interface is crucial for high-performance photoelectrodes, as it directly influences the availability of surface charges for solar water oxidation. However, establishing strong molecular-level connections between these interfaces to achieve superior interfacial quality presents significant challenges. This study introduces an innovative electrochemical etching method that generates a high concentration of oxygen vacancy sites on BiVO4 surfaces (Ov-BiVO4), enabling interactions with the oxygen-rich ligands of MIL-101. This reduces the formation energy and promotes conformal growth on BiVO4. The Ov-BiVO4/MIL-101 composite exhibits an ideal semiconductor/cocatalyst interface, achieving an impressive photocurrent density of 5.91 mA cm-2 at 1.23 VRHE, along with excellent stability. This high-performing photoanode enables an unbiased tandem device with an Ov-BiVO4/MIL-101-Si solar cell system, achieving a solar-to-hydrogen efficiency of 4.33%. The molecular-level integration mitigates surface states and enhances the internal electric field, facilitating the migration of photogenerated holes into the MIL-101 overlayer. This process activates highly efficient Fe catalytic sites, which effectively adsorb water molecules, lowering the energy barrier for water oxidation and improving interfacial kinetics. Further studies confirm the broad applicability of oxygen vacancy-induced molecular epitaxial growth in various MOFs, offering valuable insights into defect engineering for optimizing interfaces and enhancing photocatalytic activity.

Ethynyl‐Linked Donor–Acceptor Covalent Organic Framework for Highly Efficient Photocatalytic H2O2 Production

AbstractPhotocatalytic H2O2 synthesis from H2O and O2 is considered to be one of the most promising alternative approaches for manufacturing H2O2. Developing highly active and selective photocatalysts is of significant in achieving efficient H2O2 photosynthesis. Herein, an ethynyl‐linked donor–acceptor covalent organic framework (COF), named EBBT‐COF, is prepared from the condensation reaction between an electron‐deficient unit 4,4′,4″‐(1,3,5‐benzenetriyltri‐2,1‐ethynediyl)tris‐benzenamine and an electron‐rich unit benzo[1,2‐b:3,4‐b′:5,6‐b″]trithiophene‐2,5,8‐tricarboxaldehyde. Powder X‐ray diffraction and N2 adsorption isotherm unveil the crystalline porous hcb network of EBBT‐COF with pores size centered at ca. 2.3 nm. Spectroscopic characterizations demonstrate the excellent visible‐light absorption capacity and enhanced photo‐induced charge separation and transport efficiency of EBBT‐COF owing to its donor–acceptor architecture. Density functional theory calculations and electrochemical tests indicate the high activity and selectivity of EBBT‐COF toward 2e− O2 reduction reaction and 2e− water oxidation reaction with triethynylbenzene and trithiophene moieties to accelerate O2‐to‐H2O2 and H2O‐to‐H2O2 conversion, respectively. These merits enable EBBT‐COF to be a promising photocatalyst toward H2O2 generation from H2O and O2 with a H2O2 yield rate of 5 686 µmol g−1 h−1, an optimal apparent quantum yield of 15.14%, a solar‐to‐chemical conversion efficiency of 1.17% (λ > 400 nm), representing one of the best performance among COF‐based photocatalysts reported thus far.

Efficient photocatalytic degradation of bisphenol A on 2D-3D spherically hierarchical structure Zn5In2S8.

Bisphenol A (BPA) poses a significant environmental threat due to its widespread use as an industrial chemical and its classification as an environmental endocrine disruptor. The urgent need for effective BPA removal has driven research toward innovative solutions. In this study, we present the synthesis and application of a novel 2D-3D spherically hierarchical Zn5In2S8 (ZIS) photocatalyst for the photocatalytic degradation of BPA under visible light for the first time. Compared to the conventional g-C3N4 photocatalyst, ZIS exhibits enhanced optical and electrical properties, leading to remarkable photocatalytic performance, with an apparent reaction rate constant of 2.36h⁻1, 6.56 times greater than that of g-C3N4. This efficacy allows for the degradation of 99.9% of BPA in just 2h. The photocatalytic mechanism of ZIS was elucidated through various material characterizations and photoelectrochemical assessments, demonstrating improved light absorption and efficient charge separation as key factors facilitating BPA degradation. Notably, ZIS maintains high photocatalytic activity and stability over multiple cycles, indicating its potential as a sustainable photocatalyst. These findings not only contribute to the development of efficient photocatalysts for environmental remediation but also underscore the significant role of Zn5In2S8 in photocatalysis and solar energy conversion.

Defects Calculation and Accelerated Interfacial Charge Transfer in a Photoactive MOF-Based Heterojunction.

Photocatalytic hydrogen production is currently considered a clean and sustainable route to meet the energy and environmental issues. Among, heterojunction photocatalysts have been developed to improve their photocatalytic efficiency. Defect engineering of heterojunction photocatalysts is attractive due to it can perform as electron trap and change the band structure to optimize the interfacial separation rate of photogenerated electron-hole pairs. Here, the MOF-based heterojunction photocatalysts with theoretically high reduction and oxidation abilities are successfully synthesized, denoted ZrO2/Pt/Zr-MOF-X, with tuned linker defectivity through an in situ electrochemical route. The defectivity are rationally calculated from the TG and 1H NMR results. A positive correlation is found between the defectivity and photocatalytic activity, and ZrO2/Pt/Zr-MOF-6 with the optimized defectivity of ca. 35% exhibits the highest hydrogen production rate of up to 2923 µmol g-1 h-1, illustrating the importance of structural defects in heterojunction photocatalysts. Ultrafast transient absorption spectroscopy and electron spin resonance results unveil the highest carrier concentration and charge separation efficiency in the defected heterostructure of ZrO2/Pt/Zr-MOF-6 through a direct Z-scheme contact, leading to its efficient photocatalysis through the high redox power.