Transfer Bridge Research Articles

Environmentally-Friendly Europium-Based Yellow Perovskite Nanocrystals with Near-Unit Efficiency for White LED.

Recently, Mn2+-doped metal halide perovskites (MHPs) have been extensively studied as they can improve the photoluminescence quantum yield (PLQY) with minimal self-absorption. However, almost all of them with high efficiency are Pb/Cd-based toxic heavy metal perovskites, which seriously limits their commercial applications. To address the dual needs of high efficiency and environmental protection, this study proposes to incorporate Mn2+ into the environmentally friendly perovskite CsEuX3 (X = Cl/Br), and further increases PLQY to 96.9% through the codoping of Tb3+, which, to the best of our knowledge, is the highest reported value of all inorganic environmentally friendly perovskites in the visible light region. It is found that the codoping of Tb3+ can reduce the host defect density and enhance the crystal field strength around Mn2+, acting as an energy transfer bridge. Additionally, Mn2+/Tb3+-codoped CsEuX3-based white light-emitting diodes (WLEDs) with a high color rendering index (Ra = 91.2) demonstrate potential for lighting applications.

Role of perovskite non-stoichiometry on catalytic oxygen dark activation for the removal of azo dyes from wastewater

Effluents of the dying and printing industries are a significant contributor to water pollution. Since synthetic dyes are primarily resistant to natural degradation, they remain in water bodies for an exceptionally long time if discharged untreated. Oxygen dark activation is a promising candidate for the degradation of azo dyes as it does not require the use of additional reagents or even the presence of light. It is an advanced catalytic oxidation process that converts oxygen dissolved in wastewater into reactive oxygen species, which subsequently break down dye molecules. The role of the catalyst is to accelerate the process by acting as a bridge for the electron transfer between the dye molecule and adsorbed oxygen. It has been reported that the textural and structural properties of the catalyst play a key role in generating reactive oxygen species. In this work, we synthesized, characterized, and evaluated a series of strontium-based perovskite oxides for the catalytic degradation of azo dyes under dark conditions. The degradation of different dyes was studied in a batch reactor under various conditions, and the reaction progress was monitored by UV-vis absorption spectroscopy. The results showed that the degradation of azo dye was faster when the azo bond was weakened by either electron-withdrawing groups or due to the formation of a stable hydrazone structure. To evaluate the effect of structural defects on the oxygen dark activation process, cation non-stoichiometry was separately introduced in the parent perovskite SrFeO3 at both A and B sites. Under identical reaction conditions, the degradation efficiency of A-site deficient perovskite Sr0.90FeO3 (94%) and B-site deficient SrFe0.80O3 (95%) was higher than the stoichiometric perovskite SrFeO3 (46%). These results demonstrate that cation deficiency in the SrFeO3 structure strongly favors the catalytic degradation of azo dyes via oxygen dark activation.

Boosting Photoluminescence of Rare-Earth-Based Double Perovskites by Isoelectronic Doping of ns2 Metal Ions.

Doping of ns2 metal ions as an energy transfer (ET) bridge can significantly elevate the photoluminescence properties. Nonetheless, the fundamental influence of ns2 metal ions on the local lattice structures remains unclear, hindering the advancement of functional materials. Herein, Sb3+ doped rare earth double perovskites is employed as a typical case to demonstrate this issue. It is found that the isoelectronic doping of Sb3+ ions not only enhances the ET efficiency but also changes their localized electronic and lattice structures. Both density functional theory (DFT) and Judd-Ofelt (J-O) theory calculations provide unambiguous evidence that the isoelectronic doping of Sb3+ ions enables a more localized charge density in the [LnCl6]3- (Ln: Lanthanide) octahedron and reduces the symmetry of the environment around the Ln3+, facilitating the radiative transition rates of Ln3+ while enhancing their ET efficiency. Compared with Cs2NaScCl6:Ln3+, the ET efficiency of Cs2NaScCl6:Sb3+/Ln3+ is enhanced by 1.5-fold, reaching up to 98.3%. To the best of available knowledge, this work is the first to unravel the intrinsic mechanism of enhanced ET process enabled by isoelectronic doping via DFT and J-O theory. This research sheds light on understanding the mechanism of photophysics and rational design of the functional perovskite materials.

In situ composite of biomass derived carbon/porous carbon nitride and its enhanced performance in solar-driven photocatalytic hydrogen evolution reaction

Converting waste organic biomass into functional carbon materials is regarded as a sustainable development strategy to address environmental pollution and energy crisis. In this work, carbon/porous carbon nitride (PCN) composite photothermal catalysts were prepared via an in-situ method with urea and phragmites spikelets as raw materials for the solar-driven hydrogen evolution reaction (HER). The biomass derived porous carbon, in close contact with PCN, not only acts as a charge transfer bridge facilitating the rapid separation and migration of photogenerated charges but also serves as a photothermal carrier to enhance the kinetic process of the photocatalytic reaction. Under simulated solar irradiation (AM 1.5 G), the optimal HER rate of the composite catalyst is 4.98 mmol g−1h−1, which is 2.1 times that of pure PCN. The physicochemical properties of the materials, including morphology, crystal structure, elemental composition and state, and energy band characteristics, were determined. Additionally, theoretical calculations were employed to explore the impact of biomass-derived porous carbon on the electronic structure and band structure of carbon nitride. This work not only broadens the range of raw materials for biomass-derived porous carbon but also provides a novel strategy for promoting photocatalytic HER through synergistic multifield effects, showing broad application prospects in the field of resource recovery and green catalysis.

Alkyl-linked TiO2@COF heterostructure facilitating photocatalytic CO2 reduction by targeted electron transport

Targeted electron transfer to catalytically active site for CO2 reduction is promising for enhancing the efficiency of artificial photosynthesis. Here, we demonstrate a design of an alkyl-linked heterostructure composing of TiO2 and a Cu-porphyrin-based covalent organic framework (TiO2@CuPorTT-COF) for the photoreduction of CO2 with H2O. Through specific coordination effect, the alkyl chain bridges TiO2 and Cu moiety in COF. Upon light illumination, the photoinduced electrons in TiO2 can be directionally transported across the interface along the alkyl chain to the Cu active sites to reduce adsorbed CO2, while the left holes are consumed by the H2O oxidation, enhancing the spatial separation and utilization of electron-hole pairs. Accordingly, the TiO2@CuPorTT-COF enables remarkably superior catalytic activities over the counterpart without the alkyl bridge for electron transfer with 5 times of CO production rate. An apparent quantum efficiency of 0.455% at 380 nm was achieved. Moreover, a dynamic evolution of Cu active site for CO2 reduction is revealed, which can be promoted by the targeting electron transport approach. This work provides a targeted electron transport strategy for constructing photocatalysts.

Ag QDs modified BiOCl/UiO-66-NH2 Z-scheme heterojunction for accelerated visible light-driven photocatalytic degradation of ciprofloxacin

Ag quantum dots (QDs) anchored on the surface of BiOCl/UiO-66-NH2 Z-scheme heterojunctions were synthesized and characterized by various techniques such as X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV–vis DRS), electrochemical impedance spectroscopy (EIS), and photoluminescence (PL). The effects of Ag QDs loading, pH values and co-existing anions on the photocatalytic performance were comprehensively analyzed. The results concluded that the Ag QDs modified catalysts exhibited excellent photocatalytic performance for the degradation of ciprofloxacin (CIP), especially, the catalyst with 5 % Ag QDs loading (referred to as ABU-5) achieved a degradation efficiency of 72 % within 120 min and the apparent reaction rate constant was 0.00538 min−1. The outstanding performance of the ABU-5 catalyst is attributed to the introduction of Ag QDs as electron transfer bridges, improving visible light absorption and enhancing charge transfer between BiOCl and UiO-66-NH2. Free radical trapping experiments and leaching tests were carried out to determine the contribution rates of reactive species to the degradation efficiency and the concentration of Ag+ in solution after the reaction. The possible degradation pathways of CIP by ABU-5 were investigated by gas chromatography-mass spectrometry (GC-MS).

Insight into the unique role of silver single-atom in atomic-thickness ZnIn2S4/g-C3N4 Van der Waals heterojunction for photocatalytic hydrogen evolution

The construction of ultra-close 2D atomic-thickness Van der Waals heterojunctions with high-speed charge transfer still faces challenges. Here, we synthesized single-layer ZnIn2S4 and g-C3N4, and introduced silver single atoms to regulate Van der Waals heterojunctions at the atomic level to optimize charge transfer and catalytic activity. At the atomic scale, the impact of detailed structural differences between the two characteristic surfaces of ZnIn2S4 ([Zn-S4] and [In-S4]) on catalytic performance has been first proposed. Experiments combined with the DFT study demonstrate that single atom Ag not only acts as a charge transfer bridge but also regulates the energy band and intrinsic catalytic activity. Benefiting from the enhanced electron delocalization, the synthesized catalyst ZIS/Ag@CN exhibits excellent photocatalytic performance, with a hydrogen production rate of 5.50 mmol·g−1·h−1, which is much higher than the reported Ag-based single-atom catalysts so far. This work provides a new understanding of atomic-level heterojunction interface regulation and modification.

Cross-domain recommender system with embedding- and mapping-based knowledge correlation

A knowledge transfer-based cross-domain recommender system is currently a research hotspot. Existing research has reached a high level of maturity in mining potential knowledge and establishing transfer mechanisms. However, most of them ignore the impact of the dissimilarity of potential knowledge on the transfer performance. Herein, a cross-domain recommender system based on knowledge correlation-induced the embedding and mapping approach is proposed, denoted by KCEM-CDRS. First, we propose a knowledge correlation measure, which captures the consistency of knowledge between the target and source domains to build the bridge for knowledge transfer. Second, we construct a joint matrix triple factorization model to solve the data sparsity in the target domain while introducing graph regularization to solve the problem of negative knowledge transfer. Results of extensive experiments on real Amazon metadata indicate that compared with three existing cross-domain recommendation methods, KCEM-CDRS shows performance improvements of 0.05–9.55 % and 0.02–2.63 % on mean absolute error and root mean square error, respectively. Additionally, the results of the ablation experiments indicate that consideration of the knowledge correlation between domains is beneficial for knowledge transfer when the density of the source domain is rich.

Synchronous reinforcement azo dyes decolorization and anaerobic granular sludge stability by Fe, N co-modified biochar: Enhancement based on extracellular electron transfer

Anaerobic digestion (AD) treatment of azo dyes wastewater often suffers from low decolorization efficiency and poor stability of anaerobic granular sludge (AnGS). In this study, iron and nitrogen co-modified biochar (FNC) was synthesized based on the secondary calcination method, and the feasibility of this material for enhanced AD treatment of azo dye wastewater and its mechanism were investigated. FNC not only formed richer conducting functional groups, but also generated Fe2+/Fe3+ redox pairs. The decolorization efficiency of Congo red and AD properties (e.g., methane production) were enhanced by FNC. After adding FNC, the content of extracellular polymeric substances (EPS) and the ratio of proteins remained stable under the impact of Congo red, which greatly protected the internal microbial community. This was mainly contributed to the excellent electrochemical properties of FNC, which strengthened the microbial extracellular electron transfer and realized the coupled mechanism of action: On the one hand, an electron transfer bridge between decolorizing bacteria and dyes was constructed to achieve rapid decolorization of azo dyes and mitigate the impact on methanogenic bacteria; On the other hand, the stability of AnGS was enhanced based on enhanced extracellular polymeric substances secretion, microbial community and direct interspecies electron transfer (DIET) process. This study provides a new idea for enhanced AD treatment of azo dyes wastewater.

Intense pulsed light-induced millisecond selective heat treatment for high-performance silicon anodes

Silicon, which is gaining prominence as a potential anode material, exhibits long-term cycle stability issues owing to volume changes during cycling. This study presents a meticulously designed Si anode that employs intense pulsed light (IPL) technology to simultaneously reduce carbon additives and construct an effective carbon quantum dot (CQD)-derived binder system. IPL, as a light-material interaction technique, offers a novel approach for selective heat treatment with remarkably short processing durations on the order of milliseconds. By comprehensively considering the geometric structure, optical characteristics, and thermal properties of each electrode component, heat transfer bridge (HTB) materials are introduced to ensure a homogeneous depth-directional heat treatment and to minimize binder decomposition in the IPL process. By employing HTB materials, the binder can reach a controlled target temperature for the condensation reaction between poly (acrylic acid) and the CQDs. Simultaneously, higher heat generation in the conductive carbon than in the binder leads to selective additional carbon reduction. This unique approach provides selective heat treatment, which cannot be achieved using conventional methods, resulting in a Si anode with excellent cyclic stability and rate capability. The versatility of the IPL technology is further demonstrated by applying it to relatively inexpensive Si microparticles.

Integration of Silver Nanoparticles into Carbon-Encapsulated Tungsten Oxide Promoting Visible-Light-Driven Photocatalytic Degradation Efficiency

WO3-based photocatalysts have garnered popularity due to their low cost and high stability. However, the strong photogenerated electron-hole recombination limits their practical applicability. Herein, we developed an innovative heterostructure that integrates silver nanoparticles (Ag NPs) into carbon-encapsulated WO3 (C-WO3) through a combination of solvothermal synthesis and photoreduction methods. Under visible light irradiation, the Ag/C-WO3 photocatalyst demonstrated significant photocatalytic activity for rhodamine B (RhB) degradation, and the fine-tuned Ag/C-WO3 photocatalyst possesses excellent RhB degradation performance, achieving a removal rate of 98.2 % with excellent photostability. The photocatalytic process follows first-order kinetics, with adsorbent diffusion identified as the rate-limiting step. The optimized Ag/C-WO3 had an apparent rate constant of 0.039 min−1, 9.75 times higher than that of the unmodified C-WO3 (0.004 min−1). The enhanced photocatalytic activity is primarily owing to the surface plasmon resonance effect of Ag NP, which increases the absorption of visible light and boosts electron generation. Additionally, the carbon layer that encapsulates WO3 serves as a bridge for electron transfer from Ag to WO3, thereby accelerating the separation of photogenerated electron-hole pairs and elevating the overall photocatalytic degradation efficiency. The Ag NP-decorated C-WO3 with superior degradation properties is expected to be a potential candidate in practical and industrial applications.

Regulating iron center by defective MoS2 for superior Fenton-like catalysis in water purification: The key role of surface interaction and superoxide radical in accelerating metal redox-cycling

Transition metals exhibit high reactivity for Fenton-like catalysis in environmental remediation, but how to save consumption and reduce pollution is of great interest. In this study, rationally designed defect-engineered Fe@MoS2 (Fe@D-MoS2) was prepared by incorporating reactive iron onto structural defects generated from the chemical acid-etching, aiming to improve the energetic consumption of the catalyst in Fenton-like applications. Morphological and structural properties were elucidated in details, the Fenton-like reactivity was evaluated with five phenolic contaminants for oxidant activation, radical generation and environmental remediation. Compared to Fe@MoS2, Fe@D-MoS2 exhibited a 18.9-fold increase in phenol degradation (0.09 versus 1.79 min−1). Quenching experiments, electron paramagnetic resonance tests and electrochemical measurements revealed the dominant sulfate and superoxide radicals. Rendered by strong metal-substrate surface and electronic interactions from regulated chemical environment and coordination structure, the inert ≡ Fe(III) was reduced to the reactive ≡ Fe(II) accompanied by the ≡ Mo(IV) oxidation to ≡ Mo(V) in MoS2 lattice, with adjacent sulfur serving as the key electron transfer bridge. Therefore, this work shows that the incorporation of reactive centers is able to boost two-dimensional sulfide materials for environmental catalysis applications.

N/O-bridge stimulated robust binding energy and fast charge transfer between carbon nanofiber and NiCo LDH for advanced supercapacitors

Layered double hydroxide (LDH)-carbon composites effectively mitigate the inherent issues of agglomeration and poor conductivity in LDH. However, the weak binding energy and insufficient charge transfer capability between LDH and carbon substrate significantly compromise the active substance loading, cyclic stability and practical capacity of the composites. Herein, N/O co-doping porous carbon nanofibers (NOPCNFs) are first prepared by blending diminutive zinc imidazolate framework-8 nanoparticles with polyacrylonitrile for electrospinning, and then densely packed NiCo LDH nanosheets are homogeneously anchored on NOPCNFs to form NiCo LDH@NOPCNFs heterostructure via a hydrothermal method. The experimental findings and density functional theory calculation results indicate that N/O atoms exhibit robust binding forces with metal atoms through enhanced electrostatic adsorption and p-d covalent hybridization, which facilitates the nucleation and development of NiCo LDH on carbon nanofibers. Meanwhile, these heteroatoms also serve as the bridge for electron transfer from NiCo LDH to NOPCNF, leading to a strong interfacial electric field, thus accelerating charge transfer behaviors. Benefitting from the synergistic interaction between NiCo LDH and NOPCNF, the obtained NiCo LDH@NOPCNFs demonstrate an elevated mass loading of active substance (55 wt%), an impressive specific capacitance of 1340 F/g at 1 A/g (based on the mass of NiCo LDH, 2463 F/g), and good cyclic durability for 5000 cycles. Moreover, an all-solid-state asymmetric supercapacitor using NOPCNFs and NiCo LDH@NOPCNFs shows promising practical application prospects. This work gives insights into the important influence of heteroatom doping in carbon, and provides a feasible approach for the efficient integration of electroactive and carbon material.

Integrating Mo2C/C as cocatalyst into S-scheme Mo2C/C/Co0.5Cd0.5S heterojunction with spatial photocarrier separation for photocatalytic synergistic H2 evolution

Reasonable design and production of potent photocatalysts for sustainable H2 production from solar energy is one of the necessary strategies in the photocatalysis process. The S-scheme heterojunction exposes remarkable superiority in boosting light harvesting and progressing photocarrier separation efficiency in the photocatalyst. Here, new S-scheme heterojunction Mo2C/C/Co0.5Cd0.5S photocatalysts, including different weights of noble metal-free Mo2C/C nanostructures as cocatalysts, were successfully synthesized. As expected, the nanocomposite structures exhibited increased photocatalytic activity relative to single Co0.5Cd0.5S. The nanocomposite containing 5 wt% Mo2C/C exhibited an increased hydrogen production efficiency of 83.86 mmol g−1 h−1, which was 8.4 times higher than single Co0.5Cd0.5S (10.06 mmol g−1 h−1). This implies that for Co0.5Cd0.5S, Mo2C/C increases visible light absorption, facilitates photocarrier separation, and boosts the H2 evolution rate. Moreover, conductive carbon nanoparticles, electron mediators with strong interfacial interaction, serve as rapid photocarrier transfer bridges between Co0.5Cd0.5S and Mo2C. In summary, the superb efficiency of Mo2C/C/Co0.5Cd0.5S is accredited to the synergistic effect between Co0.5Cd0.5S and Mo2C/C, the creation of S-scheme heterojunction, which assists the separation of photocarriers and declines the recombination possibilities. This research ensures a reference and new profound insight for understanding and designing noble metal-free cocatalyst-assisted S-scheme heterojunctions for immensely efficient photocatalytic H2 production.

Constructing coordination-connected flexible-rigid structures for the interfacial enhancement of CF/polyetheretherketone composites

Carbon fiber (CF) reinforced polymer composites have found widespread application due to their exceptional properties, including high specific strength and modulus, thermal stability, and chemical durability. However, since the interface serves as the bridge for load transfer between fiber and resin, the interfacial property directly affects the holistic performance of the composites. Considering the inertness of CF and polyetheretherketone (PEEK), as well as the modulus gap between them, we propose a flexible-rigid sizing agent to enhance the interfacial interaction. The sizing layers are constructed by the transition layer of polyetherimide (PEI) and the hybrid nanoparticles consisting of rare-earth coordination bonded flexible aramid nanofiber and rigid nano-TiO2. Calculated by density functional theory (DFT), the electron density difference (EDD) result displays the transfer of electrons between aramid nanofiber and nano-TiO2 acted by rare-earth element. This treatment with flexible-rigid sizing agent significantly improves the surface activity, roughness, and wettability of CF. Meanwhile, the flexural strength and interlaminate shear strength (ILSS) of as-prepared CF/PEEK composites are 91.4% (810.2 MPa) and 58.2% (82.6 MPa) higher than those of unmodified CF/PEEK composites. This work presents a robust and promising approach for fabricating high-performance CF/PEEK composites.

The Sb–N charge transfer bridge over Cs3Sb2Br9/Sb–C3N4 Z-scheme heterojunction for boosting photocatalytic CO2 reduction

The Sb–N charge transfer bridge over Cs3Sb2Br9/Sb–C3N4 Z-scheme heterojunction for boosting photocatalytic CO2 reduction

Preparation and electrochemical properties of flexible self-supported graphene/silicon/carbon nanotube composite electrode for lithium-ion battery

To meet the demand of flexible devices, it was urgent to develop flexible high-capacity electrodes for lithium-ion batteries (LIBs). Silicon (Si) as an active material would effectively elevate the specific capacity of LIBs, but the drastic volume changes and low intrinsic conductivity seriously affected its electrochemical performance during the charge-discharge process. In this research, a new type of composite was designed using two-dimensional reduced graphene oxide (rGO), one-dimensional carbon nanotubes (CNTs), and silicon nanoparticles (Si NPs) as raw materials. The prepared rGO/Si/CNTs composite had an intricate and intersecting porous network structure inside, with rGO as the substrate, CNTs as a bridge, and Si NPs as the active material. The rGO would provide abundant attachment sites for Si NPs, improve electrode conductivity, and alleviate the volume change of electrode. CNTs can effectively suppress the stacking of rGO layers and generate more voids for the reaction, and also serve as a bridge for electron transfer between rGO layers. Furthermore, the interaction between each other also heightened the flexibility and strength of electrodes. Compared to the other composites, rGO/Si/CNTs=2:2:1 electrodes presented the superior electrochemical performance. When cycled at 200 mA g−1, its discharge capacity was 2217.2 mAh g−1 after 200 cycles. As the current density increasing to 1000 and 5000 mA g−1, the discharge capacity maintained at 1877.2 and 534.8 mAh g−1 for 1000th cycle, and it also demonstrated superior rate performance. Besides, the assembled flexible battery maintained a good current output under various bending conditions, and was expected to be widely used in the flexible wearable energy storage devices.

Lignin-derived carbon as rapid charge-transfer bridge for efficient solar-driven H2O2 production over CN/Mxene heterojunction

Graphitic carbon nitride (g-C3N4, CN) has been recognized as an environmentally friendly, and promising photocatalyst, particularly for solar-driven synthesis of hydrogen peroxide (H2O2). Heterostructure engineering to decorated CN is an effective approach for boosting photocatalytic H2O2 production. However, the current challenge lies in the efficient transmission of interfacial charge carriers. Herein, we propose a breakthrough approach to synthesize g-C3N4/Mxene (CNM) composites with lignin-derived carbon (L) as a bridge for electron transfer. The optimal ternary heterojunction (CNM,L) demonstrated its impressive performance (0.75 mmol/L) for photocatalytic H2O2 production, which was three times higher than that of pristine CN. The significance of lignin-derived carbon in g-C3N4/Mxene composites not only improves light adsorption, but also promotes electron transfer between the interfacial g-C3N4 and Mxene during the oxygen reduction reaction (ORR) process for H2O2 evolution. This work provides an eco-friendly design of lignin-derived carbon, which efficiently tunes the photo-generated charge transfer of CN-based photocatalysts for H2O2 generation.

Nano-photosensitizers with gallic acid-involved Fe–O–Cu “electronic storage station” bridging ligand-to-metal charge transfer for efficient catalytic theranostics

NH2-MIL-88B (Fe) (MOF) is a promising photocatalytic material for antitumor therapy because of its distinctive electronic structure. However, inadequate separation of photo-generated electrons and slow reaction rate in low/high-valence iron (Fe) cycles limit their clinical application. In the present study, “electronic storage station” as a ligand-to-metal charge transfer bridge bond was constructed to inhibit recombination of electron/hole under 650 nm laser irradiation. Cupric (Cu) ions and gallic acid (GA) were self-assembled into a MOF (denoted as CGMOF) to create an FeO(GA)Cu bridge bond. GA, characterized by robust electron delocalization and abundant electron-donating groups, significantly enhances electron transfer efficiency for photodynamic therapy (PDT). CGMOF can respond to endogenous glutathione and release cuprous ions, accelerating the iron ion/ferrous ion cycles for chemodynamic therapy (CDT). The released Fe species can serve as T2-weighted magnetic resonance imaging contrast. Extended X-ray absorption fine structure spectra confirmed the presence of GA-containing FeOCu bonds in CGMOF. Furthermore, a series of photo-electrochemical tests confirmed that the formation of FeO(GA)Cu bond prominently elevated the redox capacity and increased the carrier density of CGMOF by 2.74-fold compared to that of MOF. In addition, cinnamaldehyde was grafted onto CGMOF for tumor-responsive hydrogen peroxide self-supply. Concurrently, hyaluronic acid was surface-modified to achieve the targeted delivery of nano-photosensitizers. In summary, this study presents an innovative approach for engineering Fe-based metal–organic frameworks for synergetic PDT/CDT applications.

Boosted charge separation in porphyrin-based MOFs/CdS photocatalyst via interfacial −N−Cd− bridge bond construction

The high interfacial charge transfer barrier has been a main thermodynamic obstacle for improving the catalytic efficiency of heterojunction materials. Optimizing the interfacial environment is an effective strategy to achieve high catalytic efficiency. Herein, the coordinate bond (−N−Cd−) is designed to connect the hafnium porphyrin−metal organic framework (HT) and CdS nanoparticles, which is systematically analyzed by the 1H NMR, FTIR, Raman and DRS, respectively. The optimized 15HT1.5 H/CdS6 composite featuring interfacial bridge bonds, exhibits an H2 production up to 11.9 mmol·g−1·h−1, which is 28.5, 52.8 and 7 times greater than pure CdS, HTH, and mechanically mixed sample without interfacial chemical bonds connected, respectively. Mechanistic study suggests that the coordination bonds between HT and CdS serve as the directional carrier transfer bridges, significantly improving interfacial charge separation and chemical stability. Moreover, the formed Z-scheme charge transfer mechanism also endows the composite with high redox ability. This strategic construction of interfacial chemical bonds within heterojunction provides an effective pathway for improving interfacial charge transfer in the heterojunction photocatalysts.