Effective Electron Transfer Research Articles

Excitation Wavelength Regulated Dynamic Luminescence in Bi/Sb co‐Doped Tin Halide for Encrypted Information Transmission and High‐Sensitivity Wavelength Sensor

AbstractThe coordination structure of Sb3+ within the host lattice critically influences its photophysical properties, sparking interest in luminescent metal halides with multiexciton emissions. Furthermore, the multi‐coordination lattice structure of Sb3+ dynamically emits light with excitation wavelength, highlighting the potential of Sb3+ ions in tuning luminescence and developing advanced optoelectronic materials. Herein, Sb3+ ions are successfully doped into Cs2SnCl6, and the obvious excitation wavelength‐dependent emission of Cs2SnCl6: Sb at room temperature is observed. To explain this phenomenon, density functional theory (DFT) calculations and time‐resolved spectra are conducted to confirm that the emission originated from two luminescence centers associated with the [SbCl6]3− and [SbCl5]2− coordination. Based on the tunable emission of Cs2SnCl6: Sb and the effective electron transfer between two triplet self‐trapped exciton states induced by Bi3+ and Sb3+, a pixelated code for information encryption is designed. The encoded patterns exhibit color changes under different UV wavelengths, enabling secure and straightforward information encryption. Furthermore, a sensitive UV wavelength sensor is prepared based on Cs2SnCl6: Bi/Sb, exploiting the monotonic relationship between chromaticity coordinates and wavelength, achieving a resolution superior to previously reported wavelength sensors. This study marks a substantial step toward advancing the multifunctional application of lead‐free metal halides.

Concurrently Boosting Activity and Stability of Oxygen Reduction Reaction Catalysts via Judiciously Crafting Fe–Mn Dual Atoms for Fuel Cells

The ability to unlock the interplay between the activity and stability of oxygen reduction reaction (ORR) represents an important endeavor toward creating robust ORR catalysts for efficient fuel cells. Herein, we report an effective strategy to concurrent enhance the activity and stability of ORR catalysts via constructing atomically dispersed Fe-Mn dual-metal sites on N-doped carbon (denoted (FeMn-DA)-N-C) for both anion-exchange membrane fuel cells (AEMFC) and proton exchange membrane fuel cells (PEMFC). The (FeMn-DA)-N-C catalysts possess ample dual-metal atoms consisting of adjacent Fe-N4 and Mn-N4 sites on the carbon surface, yielded via a facile doping-adsorption-pyrolysis route. The introduction of Mn carries several advantageous attributes: increasing the number of active sites, effectively anchoring Fe due to effective electron transfer to Mn (revealed by X-ray absorption spectroscopy and density-functional theory (DFT), thus preventing the aggregation of Fe), and effectively circumventing the occurrence of Fenton reaction, thus reducing the consumption of Fe. The (FeMn-DA)-N-C catalysts showcase half-wave potentials of 0.92 and 0.82V in 0.1M KOH and 0.1M HClO4, respectively, as well as outstanding stability. As manifested by DFT calculations, the introduction of Mn affects the electronic structure of Fe, down-shifts the d-band Fe active center, accelerates the desorption of OH groups, and creates higher limiting potentials. The AEMFC and PEMFC with (FeMn-DA)-N-C as the cathode catalyst display high power densities of 1060 and 746mWcm-2, respectively, underscoring their promising potential for practical applications. Our study highlights the robustness of designing Fe-containing dual-atom ORR catalysts to promote both activity and stability for energy conversion and storage materials and devices.

Redox Noninnocent Copper(I) Complex Where Metal Is a Spectator and Ligand Is an Actor in the Glaser Coupling Reaction of Alkynes.

An extended trisazo dipyridyl ligand, L, and its copper(I) complex, [1]+, were synthesized and fully characterized. Complex [1]+ has five coordination geometry satisfied by ligand L. L has a low-lying π* orbital; thus, [1]+ showed very facile multiple ligand-based redox events. Moreover, due to the strong π-acceptor nature of L, the Cu(II)/Cu(I) redox potential of [1]+ was anodic (0.62 V). The redox events of both L and [1]+ were characterized using various spectroscopic studies and density functional theory (DFT) calculations. Taking advantage of the multiple facile ligand-based reductions in [1]+, the Glaser coupling reaction of terminal alkynes was explored. Various kinds of alkynes were found to be effective when using [1]+ as a precatalyst. The mechanism of the reaction was investigated thoroughly by several controlled experiments, isolation, and characterization of the intermediates using various spectroscopic studies as well as by single-crystal X-ray structure determination. These studies showed that the L in [1]+ acted not only in the electron transfer events but also as a locus for binding the substrate, breaking and forming bonds, and, finally, releasing the product. Thus, here, the metal mainly acted as a spectator and ligand L acted as an actor.

AIE Active Polymeric Fluorescent Nanoaggregates from Glycogen for Sensitive Detection of Tetracycline.

Detection and monitoring of environmental contaminants such as antibiotic residues in aquatic environments is challenging. To address this, a variety of detection methods has been developed; out of which optical sensing using fluorescence is found as one of the most robust methods. However, most of the reported sensors are made from metal ions using tedious synthetic processes, on the other hand, optical sensors using biosourced polymers are rarely reported. Herein, an anionic glycogen functionalized aggregation induced emission (AIE) active system; NCMCTPN was prepared using a simple Schiff base condensation reaction of tetraphenylethene amine (TPENH2) and carboxymethyl cellulose dialdehyde (NCMCA) and its self-assembled polymeric nanoaggregates were explored for sensitive and selective turn-off fluorescence detection of a broad-spectrum tetracycline antibiotic, in an aqueous medium with a limit of detection of 127.5 ppb. The combination of factors such as inner filter effect and photoinduced electron transfer from the polymeric nanoaggregates to tetracycline through activation of a non-radiative decay process is possibly responsible for the high sensitivity of the fluorescent nanoprobe towards the antibiotic.

Two-dimensional QDs-Co-CuS1-x/Ti3C2/TiO2 heterojunction with synergistic unsaturated bimetal sites and sulfur vacancies for highly selective photocatalytic CO2 reduction

The primary factors that determine the efficiency and selectivity of multi-electron photoreduction of CO2 include the chemical properties of the active sites, as well as the kinetics of charge separation and transfer. Herein, a novel two-dimensional QDs-Co-CuS1-x/Ti3C2/TiO2 heterojunction is developed, with Co-CuS1-x quantum dots serving as cocatalysts and Ti3C2 MXene as an effective electron transfer channel. The anchoring effect of Ti3C2 facilitates the formation of robust TiS bonds with Co-CuS1-x, thereby promoting efficient separation and transfer of photoelectrons to the Co-Cu bimetallic active sites. This process enhances the local electron density at these sites and accelerates the kinetics of electron transfer to absorbed CO2. The recyclability of the Co-Cu sites is also significantly enhanced by continuous photoelectron injection. Importantly, DFT calculations indicate that the synergistic dual sites involving highly exposed Co-Cu and S vacancies promote rate-determining step from COO* to COOH*, which may account for the highly selective photoreduction of CO2-to-CO. Benefitting from the synergic effects of the active sites and efficient separation of carriers, the optimized Co-CuS1-x/Ti3C2/TiO2 exhibits a satisfactory CO photoreduction rate of 30.8 µmol∙g−1∙h−1, with an excellent selectivity of 87.9 % and apparent quantum yield of 0.61 % in the absence of any sacrificial reagents, which is 6.5 times higher than Co-CuS1-x, 54.0 times than Ti3C2Tx/TiO2.

Carbonised Typha tassel-modified enzymatic electrodes for ferrocene-mediated glucose biosensor and glucose/air biofuel cell applications

This study demonstrates the application of carbonised Typha tassel (CTT) in ferrocene-mediated enzymatic glucose biosensing and enzymatic biofuel cell (EnBFC) applications. Typha tassel was carbonised under an inert atmosphere to obtain conductive CTT which was then mixed with an effective electron transfer mediator, ferrocene (Fc) obtaining a redox-active electrode material. The successful immobilisation of the glucose oxidase (GOx) enzyme was performed on a CTT-Fc modified screen-printed electrode followed by a chitosan protective coating. The resulting enzymatic electrode was electrochemically characterised as a glucose biosensor with a working range of 0–10 mM and LOD and LOQ values of 0.19 mM and 0.56 mM, respectively. The developed glucose biosensor also showed good reproducibility and reusability with RSD% values of 6.68 % and 8.75 %, respectively. Furthermore, a real sample demonstration was performed using commercial jam samples with good recovery values. Finally, an EnBFC demonstration was performed using the enzymatic biosensor as an anode and a non-enzymatic cathode prepared using platinum black on gas diffusion carbon electrodes reaching a maximum power density of 3.6 µW cm−2. This study shows the promise of CTT as an alternative to conventional materials in enzymatic biosensor and bioelectronic applications as a suitable, cheap, and sustainable material.

DFT Analysis on Adipic Acid to Propel Creative Advancements in Supercapacitor Technology

The increasing dependence on non-renewable resources for energy storage has accelerated the development of supercapacitor technology, which is now essential to portable devices and electric cars because of its high-power density and quick charge/discharge speed. Optimized geometry, weak C-H‧‧‧O hydrogen bonding interactions inside methylene groups affect bond lengths, and the carboxylic group in adipic acid (ADPI) shortens bond lengths (C14–C15 and C4–C5). DFT simulations demonstrate a fair agreement to experimental data. According to vibrational studies, the O-H and C=O groups' vibrational frequencies are greatly influenced by the reactive hydrogen bonding displayed by the -COOH group in carboxylic acid derivatives. With theoretical values demonstrating significant PED contributions, these interactions reduce the O-H stretching frequency, which is seen as an O-H stretching band at 3405 cm⁻¹ in the FT-IR spectra. In ADPI, atoms interact with neighboring atoms' σ* orbitals (O2-C4), (O12-C14), (C4-C5), (C14-C15), (O1-C4), and (O11-C14) through lone pairs of electrons localized on O1 (LP2), O11 (LP2), O2 (LP1), and O12 (LP1); these interactions have fairly high stabilization values of 33.78, 33.78, 17.91, 17.91, 6.75, and 6.75 kcal/mol, accordingly. Redox peaks and increased specific capacitance with scan rate are revealed by cyclic voltammetry study of ADPI, suggesting efficient electron transport, improved charge storage, and encouraging prospects for electrochemical energy storage applications. ADPI's appropriateness for high-performance electrochemical applications such as supercapacitors is supported by its impedance analysis, which is displayed by a Nyquist plot with a decreased semicircle and a sharp low-frequency slope. This plot demonstrates effective electron transfer, ion diffusion, and capacitive behavior.

Electron Transfer Mediator Modulates Type II Porphyrin-Based Metal-Organic Framework Photosensitizers for Type I Photodynamic Therapy.

Photodynamic therapy (PDT), a minimally invasive and effective local treatment, heavily depends on photosensitizer (PS) performance and oxygen availability. Despite the use of PS-based metal-organic frameworks (MOFs) to address the solubility and aggregation issues of PSs, the inherent hypoxic intolerance of mainstream Type II PDT remains challenging. Herein, we report an electron transfer strategy for the fabrication of hypoxia-tolerant Type I MOFs by encapsulating thymoquinone (TQ) into existing Type II MOFs. With TQ serving as an effective electron transfer mediator, it facilitates the electron transfer process from the MOF ligand PS to oxygen, establishing the Type I pathway and attenuating the original Type II pathway. Four representative porphyrin-based MOFs are synthesized to demonstrate the proposed strategy. Our findings reveal that TQ@MOF-1 nanoparticles (NPs) exhibit enhanced anticancer activity under hypoxic conditions and superior in vivo antitumor efficacy compared to parent MOF-1 NPs. This work offers an effective and universal strategy to modulate ROS generation in PS-based MOFs, endowing hypoxic tolerance with improved PDT performance against solid tumors.

Electron Transfer Mediator Modulates Type II Porphyrin‐Based Metal‐Organic Framework Photosensitizers for Type I Photodynamic Therapy

Photodynamic therapy (PDT), a minimally invasive and effective local treatment, heavily depends on photosensitizer (PS) performance and oxygen availability. Despite the use of PS‐based metal‐organic frameworks (MOFs) to address the solubility and aggregation issues of PSs, the inherent hypoxic intolerance of mainstream Type II PDT remains challenging. Herein, we report an electron transfer strategy for the fabrication of hypoxia‐tolerant Type I MOFs by encapsulating thymoquinone (TQ) into existing Type II MOFs. With TQ serving as an effective electron transfer mediator, it facilitates the electron transfer process from the MOF ligand PS to oxygen, establishing the Type I pathway and attenuating the original Type II pathway. Four representative porphyrin‐based MOFs are synthesized to demonstrate the proposed strategy. Our findings reveal that TQ@MOF‐1 nanoparticles (NPs) exhibit enhanced anticancer activity under hypoxic conditions and superior in vivo antitumor efficacy compared to parent MOF‐1 NPs. This work offers an effective and universal strategy to modulate ROS generation in PS‐based MOFs, endowing hypoxic tolerance with improved PDT performance against solid tumors.

Modulating Electronic Structure of Amorphous Indium Oxide for Efficient Formate Synthesis Towards CO2 Electroreduction.

Tuning the electronic structure of catalysts is an efficient approach to optimize the catalytic performance of CO2 electroreduction. Herein, we constructed an efficient catalyst consisting of amorphous InOX with a cotton-like structure spreading over N doped carbon (N-C) substrate to extend the catalysts-substrate interfaces for enhancing electron-transfer effect. The amorphous InOX growing on N-C substrate (InOX/N-C) exhibited an improved current density of -34.4 mA cm-2. Notably, a faradaic efficiency for formate (HCOO-) over the amorphous InOX/N-C reached 79.6 % at -1.0 V versus reversible hydrogen electrode, 1.8 times as high as that (44.2 %) over the amorphous InOX growing on carbon black substrate. Mechanistic studies revealed that the introduction of N-C as substrates accelerated charge-transfer process on the catalytic surface of InOX/N-C. Density functional theory calculations further revealed that the interactions between N-C substrate and InOX not only facilitated the potential-determining *HCOO protonation, but also inhibited hydrogen evolution, thus improving the catalytic performance for the production of HCOO-.

Design of novel Z-scheme Ce2(WO4)3 heterostructure using tubular g-C3N4 for boosted photocatalytic performance via effective electron transfer pathway

Herein, we report a novel Z-scheme heterostructure catalyst based on tubular shaped graphitic carbon nitride with cerium tungstate catalysts synthesized by ultrasonic-assisted thermal impregnation route. The physicochemical, morphological and optical features of the materials were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance (UV–vis DRS), photoluminescence (PL) spectroscopy and N2-adsorption-desorption measurements. The results demonstrated that the Ce2(WO4)3/g-C3N4 hybrid catalyst achieved superior photocatalytic activity although they had poor performance individually. The kinetic rate constant of the hybrid sample was calculated as 0.0134 min-1 which was 3.4 times higher than the pristine Ce2(WO4)3 for the degradation of tetracycline antibiotic under visible light irradiation. The improved catalytic activity was assigned to higher surface area, narrower band gap energy and formation of Z-scheme heterojunction mechanism between Ce2(WO4)3 and g-C3N4 according to band structure analysis. This research demonstrated the potential utilization and modification of Ce2(WO4)3 as a new metal tungstate in the photocatalytic remediation of different types of pollutants.

Harnessing 4f Electron Itinerancy for Integrated Dual-Band Redox Systems Boosts Lithium-Oxygen Batteries Electrocatalysis.

In-depth comprehension and manipulation of band occupation at metal centers are crucial for facilitating effective adsorption and electron transfer in lithium-oxygen battery (LOB) reactions. Rare earth elements play a unique role in band hybridization due to their deep orbitals and strong localization of 4 f electrons. Herein, we anchor single Ce atoms onto CoO, constructing a highly active and stable catalyst with d-f a dual-band redox center. It is discovered that the itinerant behavior of 4 f electrons introduces an enhanced spin-orbit coupling effect, which facilitates ideal σ/π bonding and flexible adsorption between the Ce/Co active sites and *O. Simultaneously, the injection of localized Ce 4 f electrons strengthens the orbital bonding capacity of Co-O, effectively inhibits the dissolution of Co sites and improves the structural stability of the cathode material. Bracingly, the Ce1/CoO-based LOB exhibits an ultra-low charge-discharge polarization (0.46 V) and stable cyclic performance (1088 hours). This work breaks through the traditional limitations in catalyst activity and stability, providing new strategies and theoretical insights for developing high-performance LOBs powered by rare-earth elements.

Conductive single enzyme nanocomposites prepared by in-situ growth of nanoscale polyaniline for high performance enzymatic bioelectrode

Enzyme-based electrochemical biosensors hold great promise for applications in health/disease monitoring, drug discovery, and environmental monitoring. However, inherently non-conductive nature of proteinaceous enzymes often hampers effective electron transfer at enzyme-electrode interface, limiting biosensor performance of enzyme bioelectrodes. To address this problem, we present an approach to synthesize polyaniline (PAN)-based conductive single enzyme nanocomposites of glucose oxidase (GOx) (denoted as PAN-GOx). To prevent multimerization of enzymes during nanocomposite synthesis and enable single enzyme wrapping, we activate GOx surface with phenylamine groups based on the programmed diffusion of reactants in the reaction solution. Subsequent in-situ polymerization enables the synthesis of nanoscale conductive PAN layer (∼2.7 nm thickness) grafted from individual GOx molecule. PAN-GOx retains 83% and 74% of its specific activity and catalytic efficiency, respectively, compared to free GOx, while demonstrating a ∼500% improved conductivity. Furthermore, PAN-GOx-based glucose biosensors show an approximately 16- and 3-fold higher sensitivity compared to biosensors prepared by using free GOx and a mixture of PAN and GOx, respectively. This study provides a facile method to fabricate conductive single enzyme nanocomposites with enhanced electron transfer, which can potentially be further modified and/or compounded with conductive materials for demonstrating high performance enzymatic bioelectrodes.

Construction of Spirocyclic Compounds via Electrochemical Intramolecular Dearomatization of Benzene Derivatives

AbstractThe spirocyclic framework is found in many natural products, some of which are biologically active. However, It remains a challenge to develop environmentally friendly and atom‐economic synthetic methods. Herein, we report an intramolecular dearomatization reaction of benzene derivatives enabled by electrochemistry‐mediated two successive single‐electron‐transfer (SET) processes, providing an alternative method for the rapid construction of spirocyclic skeletons without using sacrificial reagents. A series of cyclohexadiene products were obtained in 25–81% yields. Furthermore, a proposed mechanism involving a sequential electron transfer event was supported by cyclic voltammetry experiments. This strategy features transition‐metal‐free conditions and easy handling, which will greatly enhance its practical utility.

Optimizing NiFe-Modified Graphite for Enhanced Catalytic Performance in Alkaline Water Electrolysis: Influence of Substrate Geometry and Catalyst Loading.

The oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) are critical processes in water splitting, yet achieving efficient performance with minimal overpotential remains a significant challenge. Although NiFe-based catalysts are widely studied, their performance can be further enhanced by optimizing the interaction between the catalyst and the substrate. Here, we present a detailed investigation of NiFe-modified graphite electrodes, comparing the effects of compressed and expanded graphite substrates on catalytic performance. Our study reveals that substrate geometry plays a pivotal role in catalyst distribution and activity, with expanded graphite facilitating more effective electron transfer and active site utilization. Additionally, we observe that increasing the NiFe loading leads to only modest gains in performance, due to catalyst agglomeration at higher loadings. The optimized NiFe-graphite composites exhibit superior stability and catalytic activity, achieving lower overpotentials and higher current densities, making them promising candidates for sustainable hydrogen production via alkaline electrolysis.

Catalyst Protonation Changes the Mechanism of Electrochemical Hydride Transfer to CO2.

It is well-known that addition of a cationic functional group to a molecule lowers the necessary applied potential for an electron transfer (ET) event. This report studies the effect of a proton (a cation) on the mechanism of electrochemically driven hydride transfer (HT) catalysis. Protonated, air-stable [HFe4N(triethyl phosphine (PEt3))4(CO)8] (H4) was synthesized by reaction of PEt3 with [Fe4N(CO)12]- (A -) in tetrahydrofuran, with addition of benzoic acid to the reaction mixture. The reduction potential of H4 is -1.70 V vs SCE which is 350 mV anodic of the reduction potential for 4 -. Reactivity studies are consistent with HT to CO2 or to H+ (carbonic acid), as the chemical event following ET, when the electrocatalysis is performed under 1 atm of CO2 or N2, respectively. Taken together, the chemical and electrochemical studies of mechanism suggest an ECEC mechanism for the reduction of CO2 to formate or H+ to H2, promoted by H4. This stands in contrast to an ET, two chemical steps, followed by an ET (ECCE) mechanism that is promoted by the less electron rich catalyst A -, since A - must be reduced to A 2- before HA - can be accessed.

Creating CoRu Dual Active Sites Codecorated Stable Porous Ceria Support for Enhanced Li-CO2 Batteries Cathodes.

Lithium-carbon dioxide (Li-CO2) battery represents a high-energy density energy storage with excellent real-time CO2 enrichment and conversion, but its practical utilization is hampered by the development of an excellent catalytic cathode. Here, the synergistic catalytic strategy of designing CoRu bimetallic active sites achieves the electrocatalytic conversion of CO2 and the efficient decomposition of the discharge products, which in turn realizes the smooth operation of the Li-CO2 battery. Moreover, obtained support based on metal-organic frameworks precursors facilitates the convenient diffusion and adsorption of CO2, resulting in higher reaction concentration and lower mass transfer resistance. Meanwhile, the optimization of the interfacial electronic structure and the effective transfer of electrons are achieved by virtue of the strong interaction of CoRu at the support interface. As a result, the Li-CO2 cell assembled based on bimetallic CoRu active sites achieved a discharge capacity of 19,111mAhg-1 and a steady-state discharge voltage of 2.58V as well as a cycle life of >175 cycles at a rate of 100mAg-1. Further experiments combined with density-functional theory calculations achieve a deeply view of the connection between cathode and electrochemical performance and pave a way for the subsequent development of advanced Li-CO2 catalytic cathodes.

Synthesis and performance evaluation of bio-derived and synthetic carbon as lithium-sulfur battery cathode

The next-generation of batteries need be both energy dense and environment friendly. Lithium sulfur batteries (LSBs) satisfy both criteria but their practical implementation is marred by the highly resistive nature of sulfur. Carbon-based cathodes play a vital role in mitigating the issue because their high conductivity allows for effective electron transfer during electrochemical cycling. Synthesis and electrochemical evaluation of carbon-based cathodes from two different sources for LSBs was carried out. Herein, two kinds of carbon, namely bio-derived carbon from coconut shells (CC500) and N-doped carbon (NC) from polyacrylonitrile fibers were synthesized and sulfur was incorporated via the melt diffusion route. The composites are characterized by PXRD and TGA, which determined 80 wt% mass loading of sulfur. The higher intensity of G-band over D-band in Raman spectroscopy indicates greater graphitic character for CC500 compared to NC. SEM images show large macro-pore like tunnels in CC500 while NC appears are irregular chunks. EDAX spectra showed 20 wt% N content in NC while CC500 is largely carbon with some minor surface oxygen. In galvanostatic charge–discharge cycling of coin cells, bare CC500/S shows better specific capacity compared to NC/S samples but the trend flips once a separator modified with 4 mg of graphene oxide (GO) is introduced (indicated as NC/S/GO4 and CC500/S/GO4). This points towards synergy between N-doped carbon and GO layer in retaining the soluble polysulfides in the catholyte region. NC/S/GO4 exhibited better capacity i.e., 1453, 1024, 866, 787, 697 mAh/g versus 1016, 779, 672, 551, 441 mAh/g offered by CC500/S/GO4 when discharged at 50, 100, 200, 300 and 500 mA/g, respectively.

Synergistic effects of MXene support and cobalt salts in dye-sensitized photocatalytic hydrogen generation

This study introduces an approach to photocatalytic hydrogen production through a dye-sensitized photocatalytic system employing MXene (Ti3C2Tx) and a non-noble cobalt metal catalyst. It was demonstrated that simple integration of eosin Y, Ti3C2Tx and cobalt salt (CoSO4) significantly enhances the photocatalytic hydrogen evolution, outperforming the corresponding system that does not include Ti3C2Tx. The key to this enhanced performance lies in the unique properties of MXene material, which facilitates effective electron transfer and acts as a support for dye and catalyst. The successful well-dispersed decoration of small (2–3 nm) cobalt-based nanoparticles on the Ti3C2Tx sheet via in situ photodeposition was confirmed by transmission electron microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The optimal hydrogen production rates were achieved with a Co to Ti3C2Tx mass ratio of 15%. This optimized interaction results in a hydrogen evolution rate of 40.1 mmol h−1 g−1 and an apparent quantum efficiency (AQE) of 35.4% at 505 nm. These findings highlight the potential of Ti3C2Tx as a versatile component in photocatalytic systems, particularly effective when paired with economically viable, earth-abundant catalysts like cobalt.

Unlocking Interfacial Interactions of In Situ Grown Multidimensional Bismuth‐Based Perovskite Heterostructures for Photocatalytic Hydrogen Evolution

AbstractTo combat the energy crisis and environmental pollution, developing renewable energy technology such as hydrogen (H2) production is necessary. The sulfur–iodine thermochemical cycle has high commercial potential in conducting hydrogen iodide (HI) splitting for H2 generation, but it requires high‐temperature conditions. In comparison, photocatalytic HI splitting of halide perovskites is non‐polluted and low‐cost for H2 production at room temperature. Herein, an in situ constructed multidimensional bismuth (Bi)‐based 3D/2D EDABiI5/MA3Bi2I9 perovskite heterojunction is developed first by synergistically integrating dimensionality control with heterostructure engineering. Accordingly, the optimal EDABiI5/MA3Bi2I9 without any co‐catalysts exhibits the H2 evolution rate of 213.63 µmol h−1g−1 under irradiation. Equally importantly, interfacial dynamics of solid/solid and solid/liquid interfaces play a crucial role in photocatalytic performance. Therefore, using temperature‐dependent transient photoluminescence and electrochemical voltammetric techniques, it is confirmed that the exciton transportation of EDABiI5/MA3Bi2I9 is accelerated by stronger electronic coupling arising from an enhanced overlap of electronic wavefunctions. Moreover, the effective diffusion coefficient and electron transfer rate of EDABiI5/MA3Bi2I9 demonstrate efficient heterogeneous electron transfer, resulting in improved photocatalytic hydrogen production. Consequently, the in situ formation of perovskite heterostructures studied by a combination of photophysical and electrochemical techniques provides new insights into green hydrogen evolution and interfacial interaction dynamics for commercial applications of solar‐to‐fuel technology.