Dual Materials Research Articles

Designing flexible TiO2/SrTiO3/BiOBr recyclable fiber membrane with spatial dual oxidation sites for photocatalytic uranium extraction under visible light

The utilization of nuclear energy generates a substantial volume of wastewater containing uranium, posing a significant threat to both aquatic ecosystems and human health. The current photocatalytic materials utilized for uranium extraction commonly exhibit insufficient redox capabilities, inefficient separation of photogenerated carriers, and challenging recovery. Therefore, recyclable TiO2/SrTiO3/BiOBr (TSB) dual Z-scheme heterojunction fiber membrane materials with dual oxidation sites were successfully synthesized, with advantages of rapid carrier separation and transfer and a broad photo-response range of the dual Z-scheme heterojunctions. Due to the presence of dual oxidation sites, TSB exhibited an exceptional uranium extraction performance, achieving a remarkable 98.9 % extraction rate without the need for sacrificial agents, which was 2.48, 1.79, and 3.34 times of those of ordinary TiO2, SrTiO3, and BiOBr, respectively. The extraction rate of uranium from TSB was 85 % after five cycles. Optical and photoelectric tests revealed that TSB reduced the bandgap width by 0.25 eV compared to that of TiO2, enhanced the fluorescence lifetime by 1.3 ns, lowered the electrical resistance, and higher optical current density, confirming the effective charge transport at the catalyst interfaces. The charge transfer routes in the TSB dual Z-scheme were confirmed by X-ray photoelectron spectroscopy and density functional theory. The potent oxidizing ·OH generated by TSB played a crucial role in facilitating the conversion of U(VI) into insoluble (UO2)O2·2H2O. In conclusion, this work provides a novel strategy for the design of dual Z-scheme heterojunctions and offers a new method for practical and recoverable uranium extraction.

Pivotal copper bimetallic oxide in hierarchical Calcium magnesium materials for low-temperature carbon capture and utilization

Carbon removal from anthropogenic greenhouse gas emissions is essential to achieve net-zero emissions and mitigate climate change, and integrated carbon capture and utilisation (ICCU) has been studied for subsequent in-situ chemical production. However, high temperature and CaO sintering remain critical issues, highlighting the need for improved, low-cost CO2 adsorbents that can be regenerated at lower temperatures. Herin, we innovatively introduce the low-temperature ICCU coupled with reverse water gas shift reactions (RWGS) using dual functional materials (DFMs), exemplifying a range of potential transition metals doped over CaO with or without the MgO support. Among all the prepared DFMs, D-Cu showed desirable enhanced catalytic activity at a comparatively low-temperature performance (550°C) and still maintained a stable CO2 capture capacity (7.0mmol g−1) and CO yield (8.0mmol g−1) with an exceptional CO2 conversion (94.4 %) and CO selectivity (97.6 %) after cyclic hydrogenation. The mechanism study revealed that Ca2CuO3 bimetalliccatalyst in the hierarchical porous 2CaO/MgO matrix of D-Cu plays a crucial role in retaining its cyclic stability, surpassing that of noble D-Pt. Given the ICCU-RWGS performance and cyclic stability of cost-effective D-Cu at reduced operating temperatures, the findings would minimise energy and cost consumption.

Environmental tradeoff on integrated carbon capture and in-situ methanation technology

Compared to conventional CO2 removal methods, carbon capture and in-situ conversion using dual function materials avoid compression and transportation of CO2, which is regarded as a promising technology. Although it brings additional economic benefits, the environmental impacts of CO2 capture and conversion remain unclear. A life cycle assessment of an integrated CO2 capture and methanation system using dual function materials is conducted to investigate its feasibility to reduce global warming. Life cycle inventory is obtained through construction, operation, and disposal process of the integrated system. A dynamic model of CO2 capture and methanation is developed to obtain the operating parameters. Results show that the optimal global warming potential is 0.706 kg CO2,eq per kilogram captured CO2, which indicates the advantages of using dual function materials for carbon mitigation. Global warming potential is a minor factor among the overall normalized environmental impacts, only accounting for 0.5 % of the total normalized impact, while the main factor marine aquatic ecotoxicity accounts for around 73 %, and fresh water aquatic ecotoxicity accounts for around 23 %. Global warming potential is the most affected by green hydrogen input, followed by dual function material input. Results reveal that the integrated CO2 capture and conversion using dual function materials is conducive to carbon mitigation but has significant other environmental impacts, such as marine aquatic ecotoxicity, and the main contributors to the environmental impacts are wind electricity, green hydrogen, refrigerator, and dual function material.

Refractive index sensing characteristics of PCF-SPR based on dual-plasmon materials

Abstract In this paper, a photonic crystal fiber (PCF) refractive index sensor based on surface plasmon resonance (SPR) with dual plasmonic materials (indium tin oxide and gold) is proposed. We innovatively designed a dual-core PCF structure and pore arrangement effectively enhancing the coupling effect. Using two different plasma materials, phase matching is achieved at two different wavelengths for the evanescent and surface plasmon waves, resulting in dual resonance peaks. The refractive index sensing is accomplished by measuring the dual-peak resonance shift, which expands the detection wavelength and RI detection ranges. The sensor can detect analytes with refractive indices ranging from 1.32 to 1.43 at wavelengths between 0.4 um and 1.4 um. We optimized the photonic crystal fiber structure and studied the sensing performance of the sensor, improving its sensitivity. Simulation results indicate that the designed PCF sensor exhibits outstanding maximum dual-peak shift sensitivity (DPSS), reaching up to 28,000 RIU-1, along with maximum amplitude sensitivity (AS) and wavelength sensitivity (WS) of 18,500 RIU-1 and 34,500 RIU-1, respectively, in the direction of y-polarization. Furthermore, the sensor achieves high resolution, and the figure of merit (FOM) values can reach up to 5.134×10-7 and 2758. Consequently, the proposed sensor can provide high-precision and extensive-range measurements of solution refractive indices within the visible and infrared light spectrum, and it holds potential application prospects in numerous fields, such as food safety testing and chemical substance detection.

Mn-enhanced performance of the Ni-CaO/γ-Al2O3 dual function material for CO2 capture and in situ methanation

The CH4 yield over dual functional materials (DFMs) remains low and requires further improvement. In this work, we first examined the influence of Mn on the performance of the Ni-CaO/γ-Al2O3 DFM for CO2 capture and in situ methanation. Our results showed that the MnNi-DFM-3 (MnNi-CaO/γ-Al2O3 DFM) exhibited the best performance at 350 °C, with a CH4 yield of 0.56 mmol/g which is 4 times higher than that of the Ni-DFM-1 (Ni-CaO/γ-Al2O3 DFM) (0.14 mmol/g). Nanoscale characterization revealed that highly scattered Mn3O4 acted as a barrier preventing the agglomeration of Ni-based catalysts. Furthermore, our density functional theory (DFT) analysis demonstrated that the introduction of Mn enhanced the activation of CO2, promoted the dissociation of H2 and intermediates, and reduced the activation energy needed to produce carboxylic acid intermediates on the Ni catalyst. The prepared MnNi-DFM is promising to be a cheap efficient material for CO2 capture and in situ methanation. This work opens up a new pathway for enhancing the performance of DFMs using inexpensive transition metals.

Promoting proximity to enhance Fe-Ca interaction for efficient integrated CO2 capture and hydrogenation

Integrated CO2 capture and utilization (ICCU) using “capture-conversion” dual functional materials (DFMs) paves a cost-effective path for restricting CO2 emissions by eliminating the energy-intensive intermediate processes. The interactions between catalysts and absorbents are believed pivotal in ICCU; however, there is a lack of environment-friendly strategy to fabricate the interaction for industrial applications. Here, we propose a solvent-free mechanochemical approach to promote the interaction by improving the proximity between natural calcium and iron sources. The interaction was systemically investigated and confirmed using XRD, XPS, TEM, TPR, etc. As a result, the mechanochemical approach derived DFM achieved 5.5 mmol/g CO2 capacity, 87 % CO2 conversion, and 100 % CO selectivity at 650 °C, significantly outperforming the CaO-alone benchmark (CO2 capacity < 4.5mmol/g, CO2 conversion < 73 %). Further incorporating MgO would alleviate the sintering and promote the CO2 capture stability (< 15 % decrease after 20 cycles) by acting as a thermal-stable barrier. Based on in situ XRD, it is further confirmed that Fe-Ca interaction exhibits a dynamic looping mechanism in ICCU. The techno-economic analysis strongly supports the superiority of ICCU catalyzed by naturally sourced DFMs on eliminating the energy and H2 consumption for CO2 capture and upgradation. As a result, producing CO via ICCU using mechanochemical derived DFMs exhibits 20 % and 10 % cost decrease compared to the conventional CCU and ICCU using CaO alone scenarios, pointing out the potential of ICCU technology in industrial applications.

Efficient sorbent/catalyst composites for CO2-mediated oxidative dehydrogenation of ethane via isothermal integrated CO2 capture and utilization

The isothermal integrated CO2 capture and utilization to produce ethylene (ICCU-ODHE) performances of dual functional materials (DFM) were improved by doping five transition metal elements (Fe, Co, Ni, Cu, Zn). The results show that the DFM doped with Zn exhibits excellent ICCU-ODHE performance with an ethylene yield of 35.1 %. The results based on in-situ XPS and DFT calculation show that the doping transition metal elements can reduce the energy barriers for activating ethane and CO2. It is mainly because doping transition metal elements with strong electronegativity can increase the coordinative unsaturated Cr3+ ions to adsorb more ethane molecules, meanwhile, the doping also reduces the charge density of Cr3+ and generates additional unfilled electron orbitals facilitating charge transfer to improve the CO2 and ethane activation. However, the decrease in charge density can increase the difficulty of ethylene desorption and reduce the ethylene selectivity. In addition, the cyclic regeneration experiment shows that the ICCU-ODHE performance of DFM can decrease with the increase of cycles, however, significant performance restoration is achievable after regeneration in the air at 650 °C, attributed to the limited graphitization of coke deposition on the DFM.

The synthesis and application of MRI-fluorescence dual mode materials with absorption ability on quantitative analysis of malachite green

The histidine/Mn3O4/CdTe quantum dots (HMQ) composites with good magnetic resonance/fluorescent imaging and absorbance performance have been prepared based on biomimetic mineralization method, on which the peptide served as a carrier to guide the formation of Mn3O4 and CdTe quantum dots. The fluorescence of HMQ could be quenched by malachite green (MG), whereas the magnetic resonance signal (T1-MRI) was enhanced. Also, there is a linear correlation between the concentrations of MG added and the decreasing fluorescence intensity of HMQ (F0/F), the detection range is 0.06851–1.096 nmol l−1, and the LOD is 0.02750 nmol l−1. The corresponding T1WI detection range is 13.7–95.9 nmol l−1, and the LOD is 7.617 nmol l−1. Furthermore, the fluorescence quenching spectra of the HMQ adopted by MG have been analyzed, of which the data fit well with the law of pseudo-second-order kinetics, indicating that the prepared HMQ has good absorption properties. Therefore, HMQ could be used as an MRI/fluorescent dual sensor for the detection of MG.

Taking dual function materials (DFM) from the laboratory to industrial applications: A review of DFM operation under realistic integrated CO2 capture and utilization conditions

Taking dual function materials (DFM) from the laboratory to industrial applications: A review of DFM operation under realistic integrated CO2 capture and utilization conditions

Li/Na/K carbonate solar salts for enhanced and integrated carbon capture and utilization via reverse water gas shift (ICCU-RWGS)

This study introduces a novel ICCU-RWGS process using Li, Na, and K carbonates mixed with boric acid as dual functional materials, enhancing CO2 capture and conversion without traditional CaO adsorbents. These molten salts, compatible with solar energy systems, enable efficient integration with CSP, storing heat from CO2 capture for utilization. The addition of boric acid significantly boosts CO2 uptake and conversion, achieving 2.0 mmol, 1.1 mmol, and 1.3 mmol CO2 uptake with conversion of 51.1 %, 58.3 %, and 57.6 % over three cycles, respectively. A 10-cycle test confirmed stable performance, with conversion rates between 53.0 % and 58.7 %. Characterization techniques (XRD, SEM, TEM, XPS, in-situ DRIFTS) revealed new borate phases after CO2 capture. TG-DSC analysis showed exothermic peaks during CO2 capture and RWGS stages, indicating that molten salt has the potential to generate heat for CSP systems, thus offering efficient CO2 conversion and sustainable energy recovery.

Potential of solar thermal collector combined with dual phase change materials for different energy demands: An energy, economic, and environmental assessment

In this study, three different types of solar thermal systems i.e. ETSC-A (lauric acid integrated with a hot water tank), ETSC-B (lauric acid integrated with hot water tank and palmitic acid with evacuated tube), and ETSC-Conv (without phase change materials) have been designed and fabricated. The energy performance of ETSC-A and ETSC-B compared to ETSC-Conv was found to be 30.94, 45.37, & 49.27 %, and 48.37, 76.36, & 57.88 % higher for ED-I, ED-II, and ED-III respectively. Concerning, techno-economic analysis, values of LCWH, NPV, and PBP for ETSC-B and ETSC-A in comparison to ETSC-Conv are found to be higher by 24.41 %, 26.44 % & 36.51 and 22 %, 24.36 % & 31.91 % respectively. About environmental scan, ETSC-B, and ETSC-A can mitigate more CO2 and generate revenue by almost 60 % and 41 % respectively than ETSC-Conv. The commercial deployment of developed systems specifically ETSC-B is not only advantageous in terms of thermal performance and economic viewpoint but also mitigates carbon dioxide emission.

Rare earth oxide promoted Ru/Al2O3 dual function materials for CO2 capture and methanation: An operando DRIFTS and TGA study

Dual-function materials (DFMs) combine sorbent and catalytic components to perform selective CO2 capture and subsequent hydrogenation. This study explores the performance of rare-earth oxides (REOs) as CO2 adsorption sites on Ru/Al2O3. REOs increase CO2 uptake by upwards of +60 % by enhancing the overall catalyst surface basicity and favoring metal–support interactions. Thermogravimetric analysis during CO2 adsorption-hydrogenation cycles exhibited significant catalytic activity and enhanced stability of Ru-REO/Al2O3 at temperatures as low as 200 °C. This leads to methane production of 50–85 µmol g−1, surpassing recently reported values obtained for alkali and alkali-earth promoted Ru-based materials operated at 250 °C. The highest performing studied DFM, RuNd2O3/Al2O3, achieved 85 % CO2 capture efficiency and steadily produced methane in cyclic operation (+120 % CO2 uptake relative to Ru/Al2O3). Operando DRIFTS revealed that the dominant mechanism for methane formation is the hydrogenation of ruthenium carbonyls, which are stabilized by REOs. Upon CO2 exposure, surface carbonates and bicarbonate species form more abundantly on DFMs than on Ru/Al2O3. This confirms that REOs enhance the adsorption and retention of carbonates, which generate additional promoter-related reaction pathways during low-temperature hydrogenation. These findings are crucial in the advancement of sustainable, wider operation range carbon capture and utilization technologies.

Cu promoted Ni-Ca dual functional materials for integrated CO2 capture and utilization in O2-containing flue gas: Eliminating the delay in the utilization stage

Integrating CO2 capture and utilization by dry reforming methane (ICCU-DRM) technology is promising in concentrating and utilizing diluted CO2 from flue gas, which depends on developing Dual Functional Materials (DFMs) with adsorption and catalytic sites. Ni-Ca materials are widely applied in ICCU-DRM due to their excellent catalytic and CO2 adsorption properties. Nevertheless, the challenge remains that oxygen in the actual flue gas would oxidize the active Ni, leading to a delay in the DRM stage. In this work, Cu-promoted, ZrO2-stabilized Ni-Ca based DFMs were developed, which suppressed the delay and enhanced the performance of the DRM reaction. Attribute to the excellent reducing properties, Cu could be rapidly reduced in the CH4 atmosphere and further promote the reduction of NiO to the catalytically active Ni monomers by activating methane to generate reactive hydrogen (H*). What’s more, attributed to the disappearance of delay times, it is accompanied by a satisfying yield distribution with a 0.11 decrease in H2/CO ratio and an improvement in conversion, especially CH4 conversion with an increase of more than 10%. In addition, the bifunctional material also exhibits favorable cycling stability due to the stabilizers.

Recent Advances in Functionalized Biomass-Derived Porous Carbons and their Composites for Hybrid Ion Capacitors.

Hybrid ion capacitors (HICs) have aroused extreme interest due to their combined characteristics of energy and power densities. The performance of HICs lies hidden in the electrode materials used for the construction of battery and supercapacitor components. The hunt is always on to locate the best material in terms of cost-effectiveness and overall optimized performance characteristics. Functionalized biomass-derived porous carbons (FBPCs) possess exquisite features including easy synthesis, wide availability, high surface area, large pore volume, tunable pore size, surface functional groups, a wide range of morphologies, and high thermal and chemical stability. FBPCs have found immense use as cathode, anode and dual electrode materials for HICs in the recent literature. The current review is designed around two main concepts which include the synthesis and properties of FBPCs followed by their utilization in various types of HICs. Among monovalent HICs, lithium, sodium, and potassium, are given comprehensive attention, whereas zinc is the only multivalent HIC that is focused upon due to corresponding literature availability. Special attention is also provided to the critical factors that govern the performance of HICs. The review concludes by providing feasible directions for future research in various aspects of FBPCs and their utilization in HICs.

Hybrid metal halide family with color-time-dual-resolved phosphorescence for multiplexed information security applications

Luminescent materials with engineered optical properties play an important role in anti-counterfeiting and information security technology. However, conventional luminescent coding is limited by fluorescence color or intensity, and high-level multi-dimensional luminescent encryption technology remains a critically challenging goal in different scenarios. To improve the encoding capacity, we present an optical multiplexing concept by synchronously manipulating the emission color and decay lifetimes of room-temperature phosphorescence materials at molecular level. Herein, we devise a family of zero-dimensional (0D) hybrid metal halides by combining organic phosphonium cations and metal halide tetrahedral anions as independent luminescent centers, which display blue phosphorescence and green persistent afterglow with the highest quantum yields of 39.9 % and 57.3 %, respectively. Significantly, the luminescence lifetime can be fine-tuned in the range of 0.0968–0.5046 μs and 33.46–125.61 ms as temporary time coding through precisely controlling the heavy atomic effect and inter-molecular interactions. As a consequence, synchronous blue phosphorescence and green afterglow are integrated into one 0D halide platform with adjustable emission lifetime acting as color- and time-resolved dual RTP materials, which realize the multiple applications in high-level anti-counterfeiting and information storage. The color-lifetime-dual-resolved encoding ability greatly broadens the scope of luminescent halide materials for optical multiplexing applications.

Intertumoral and intratumoral barriers as approaches for drug delivery and theranostics to solid tumors using stimuli-responsive materials.

The solid tumors provide a series of biological barriers in cellular microenvironment for designing drug delivery methods based on advanced stimuli-responsive materials. These intertumoral and intratumoral barriers consist of perforated endotheliums, tumor cell crowding, vascularity, lymphatic drainage blocking effect, extracellular matrix (ECM) proteins, hypoxia, and acidosis. Triggering opportunities have been drawn for solid tumor therapies based on single and dual stimuli-responsive drug delivery systems (DDSs) that not only improved drug targeting in deeper sites of the tumor microenvironments, but also facilitated the antitumor drug release efficiency. Single and dual stimuli-responsive materials which are known for their lowest side effects can be categorized in 17 main groups which involve to internal and external stimuli anticancer drug carriers in proportion to microenvironments of targeted solid tumors. Development of such drug carriers can circumvent barriers in clinical trial studies based on their superior capabilities in penetrating into more inaccessible sites of the tumor tissues. In recent designs, key characteristics of these DDSs such as fast response to intracellular and extracellular factors, effective cytotoxicity with minimum side effect, efficient permeability, and rate and location of drug release have been discussed as core concerns of designing paradigms of these materials.

Effect of Li-Na sorbent phase in Ru/Al2O3 dual function materials for the Integrated CO2 capture and methanation

The design of highly performing dual functional materials (DFMs) is the key to the successful deployment of Integrated Carbon Capture and Methanation (ICCM) process that combines both steps into a single unit operation with high energy efficiency. Intending to enhance the CO2 working capacity while preserving high catalytic methanation activity, herein we set out to investigate the effect of combining Li and Na as the CO2 sorbent phase in Ru/Al2O3 DFMs. ICCM tests in a fixed bed reactor operated with alternate feeds indicated that combining Na with Li (or partially substituting it for Li) effectively increases the CO2 capture capacity and methane production of the DFM. However, this generally requires higher temperatures to properly activate the catalytic methanation and to regenerate the DFM compared to a pure Li-based formulation. Transient operando DRIFTS and catalytic kinetic experiments provided mechanistic insights into the activation/inhibition of different reaction paths on those DFMs containing only Li and/or Na.

Enhancing Air Conditioning System Performance via Dual Phase Change Materials Integration: Seasonal Efficiency and Capsulation Structure Impact

Enhancement of the cooling and heating capabilities of an air conditioning unit (ACU) coupled with a thermal energy storage system of dual phase change materials (PCM) is investigated. The dual PCM, namely SP24E and SP11_gel, are coupled with the ACU outdoor device (condenser/evaporator) during the summer/winter seasons, respectively. Moreover, ACU performance assisted with dual-PCM heat exchanger is compared with a single heat exchanger of SP24E in summer and single heat exchanger of SP11_gel in winter at different PCM capsulation structures (aligned and staggered cylinders). The system dynamic mathematical model is computationally solved using ANSYS software and experimentally validated. Results affirm that charging/discharging periods are minimal for the dual-PCM system and slower for PCM inline cylinder layouts than staggered ones. Inline design yields greater ACU average power savings. In summer, higher inlet air temperature to the PCM system reduces PCM discharging time and ACU power savings, with the opposite effect during winter. ACU COP with PCMs is improved by around 80 % in summer and 40 % in winter, respectively, compared to ACU without PCMs. The maximum average power saving over 4 h of ACU working in summer by single and dual-PCM systems is 21.4 % and 11.8 %, respectively, whereas the results in winter are 18.5 % and 12.8 %, respectively.

Preparation of three dimensional boron nitride-aluminum oxide dual thermal network resin-based composite materials and their performance study

With the gradual miniaturization and integration of electronic devices, the design and development of new high thermal conductivity polymer-based composite materials are crucial for enhancing the performance of modern electronic devices. In this study, three-dimensional boron nitride (3D-BN) aerogels with vertically aligned structures were prepared using the ice templating method, serving as the primary thermal conductive network. Subsequently, aluminum oxide (Al2O3)/epoxy resin (EP) nanofluids were infiltrated into the aerogel’s air pores using vacuum impregnation. The Al2O3 particles in contact with each other formed the secondary thermal conductive network. Thus, a 3D BN-Al2O3/EP composite material with a dual thermal conductive network structure was successfully fabricated. The composite material exhibited a high thermal conductivity coefficient of 1.077 Wm−1K−1 when loaded with 17.67 wt% BN and 26.23 wt% Al2O3, representing a 496 % increase compared to pure EP and a 211 % increase compared to 3D-BN/EP composite materials. Furthermore, this composite material demonstrated excellent thermal stability and mechanical properties. This work provides a new direction for designing novel polymer-based composite materials with low filler loading and high thermal conductivity performance.

Switchable Dual Circularly Polarized Luminescence in Through-Space Conjugated Chiral Foldamers.

Organic materials with switchable dual circularly polarized luminescence (CPL) are highly desired because they can not only directly radiate tunable circularly polarized light themselves but also induce CPL for guests by providing a chiral environment in self-assembled structures or serving as the hosts for energy transfer systems. However, most organic molecules only exhibit single CPL and it remains challenging to develop organic molecules with dual CPL. Herein, novel through-space conjugated chiral foldamers are constructed by attaching two biphenyl arms to the 9,10-positions of phenanthrene, and switchable dual CPL with opposite signs at different emission wavelengths are successfully realized in the foldamers containing high-polarizability substitutes (cyano, methylthiol and methylsulfonyl). The combined experimental and computational results demonstrate that the intramolecular through-space conjugation has significant contributions to stabilizing the folded conformations. Upon photoexcitation in high-polar solvents, strong interactions between the biphenyl arms substituted with cyano, methylthio or methylsulfonyl and the polar environment induce conformation transformation for the foldamers, resulting in two transformable secondary structures of opposite chirality, accounting for the dual CPL with opposite signs. These findings highlight the important influence of the secondary structures on the chiroptical property of the foldamers and pave a new avenue towards efficient and tunable dual CPL materials.