Simple Device Structure Research Articles

In2O3/g-C3N4/Au ternary heterojunction-integrated surface plasmonic and charge-separated effects for room-temperature ultrasensitive NO2 detection

Light-activated gas sensors based on semiconducting metal oxides (SMOs) hold great promise for next-generation gas sensing application, due to their unique superiority including room-temperature operation, intrinsic safety, and simple device structure. However, poor visible-light absorption and fast carrier recombination of SMOs sensing film are two main barriers that seriously restrict their sensing performance of light-activated gas sensors. Herein, a visible-light activated gas sensor based on Au nanoparticles modified In 2 O 3 /g-C 3 N 4 heterojunction nanofibers is developed. Excellent sensing response (R g /R a = 17.2 to 1 ppm NO 2 , where R a and R g represent the resistance of sensors when exposed to air or target gas) and fast response/recovery kinetics at room temperature are obtained, which is markedly better than the sensors based on pristine In 2 O 3 nanofibers and In 2 O 3 /g-C 3 N 4 nanofibers. Through the discussion and estimation of experimental results, the improved gas sensing properties of In 2 O 3 /g-C 3 N 4 /Au-based sensors are speculated to be related to the enhanced visible light utilization benefiting from localized surface plasmon resonance (LSPR) effect of Au nanoparticles, and the efficient separation of photo-generated carriers enabled by heterojunctions between In 2 O 3 , Au, and g-C 3 N 4 components. The current work will provide a universal strategy to develop high-performance light-activated gas sensor and a deep understanding about the sensing principle of this novel type of gas sensor. • The built-in electric field of In 2 O 3 /g-C 3 N 4 heterojunctions could effectively separate the photogenerated carries. • The LSPR effect of Au nanoparticles extends the visible-light absorption range of sensing materials. • The Schottky junctions formed on the interface of Au and SMOs could increase the separation of photogenerated carries. • The Au nanoparticles could promote the chemical adsorption of NO 2 molecules on the sensing materials.

Electrochemical Sensor Applications of Nanoparticle Modified Carbon Paste Electrodes to Detect Various Neurotransmitters: A Review

Neurotransmitters are synapses transmitting messengers that are vital towards human wellness. Any abnormality in their behaviour can lead to huge psychological ailments such as Parkinson's, Alzheimer's, and Schizophrenia. During diagnosing and assessing mental diseases, it is critical to discover distinct measures of different neurotransmitters present. A combination of nanomaterials, proteins, and polymers are employed to create suitable detecting and sensing component systems. Electrochemical detection has been widely employed for in-vivo detection, with FSCV emerging as the most promising technology to date due to advantages such as high sensitivities, simple device structure, and facile downsizing. Excessive background noise and signal, restricted target selectivity, declination with time, and the device fouling are all issues that in-vivo electrochemical neurotransmitter indications encounter. Nanomaterials have sparked a tremendous focus in recent years owing to their diverse properties. CPEs are amongst the safest and most ecologically beneficial electrodes with a vast scope of applications due to their incredibly simple and rapid manufacturing method, lower back - ground current, relatively inexpensive, adaptability to numerous modifiers and modifying techniques, so on and so forth.

High-performance CsGeBr3 perovskite/ WS2 Nano-Flakes Field-Effect Transistor at high temperature

This study explores the current-voltage characterization of tungsten disulfide Nano-Flakes (WS 2 NFs) Field-Effect-Transistor (FET) under various temperatures with a simple back-gate device structure. Due to the non-toxic nature of inorganic perovskite CsGeBr 3 (CGB), this material is applied to fabricate a CGB/WS 2 FET by drop-casting of lead-free perovskite CGB on the WS 2 NFs FET. The characterization of fabricated two FET devices has been performed under the illumination of a laser source (at a wavelength of ∼532 nm) with three different temperatures (298°, 313°, and 333° K). The output and transfer characteristics of CsGeBr 3 /WS 2 NFs FET illustrate that CGB is very effective in boosting the photocurrent and performance of the FET. For each two FET devices, increasing the temperature led to a decrease in drain-source current (I ds ), whereas the rate of I ds reduction in CGB/WS 2 NFs FET is roughly two times less than WS 2 NFs FET. The results demonstrate that the conductivity and I ds of the CGB/WS 2 NFs FET have been doubled compared to the bare WS 2 -NFs FET. Most importantly, the CGB/WS 2 NFs FET shows higher external quantum efficiency, photo-responsivity, and detectivity in comparison with the WS 2 NFs FET. The superior photo-sensing properties of the CGB/WS 2 NFs FET are very promising to extend the two-dimensional optoelectronic devices with excellent performance. • CGB is effective in boosting the photocurrent. • I ds reduction rate in CGB/WS 2 NFs FET with increasing temperature is roughly two times less than WS 2 NFs FET. • Conductivity and I ds of the CGB/WS 2 NFs FET double compared to the bare WS 2 -NFs FET. • CGB/WS 2 NFs FET shows higher external QE, photo-responsivity, and detectivity in comparison with WS 2 NFs FET.

Doubling and tripling the absorption peaks of a multi-band graphene terahertz absorber

Tunable terahertz (THz) absorber is a hot research topic in recent years. However, absorption peak number control is rarely studied. A multi-band THz absorber based on a horizontal array of vertically offset graphene nanoribbon pairs is proposed and numerically investigated. By asymmetrically widening the lower layer graphene nanoribbons, two new absorption peaks are added due to the effective excitations of even-mode lateral Fabry-Perot resonances. By different Fermi energy applying strategies, doubling and tripling of the absorption peak number can be realized. Besides, the relatively simple device structure reduces the difficulty of subsequent fabrications. The proposed peak number controllable multi-band THz absorber shows promise in the areas of sensing, non-destructive testing, explosive detection and etc.

Ammonia sensing characteristics of a cerium oxide thin film coated with platinum nanoparticles

This paper reports on ammonia (NH 3 ) sensing characteristics of a new semiconducting metal oxide (SMO) sensor. employing a cerium oxide (CeO 2 ) thin film and platinum (Pt) nanoparticles (NPs) as a sensing layer. The thickness of CeO 2 thin film is 30 nm and the particle size of Pt NPs is about 4–6 nm. Based on the enhanced surface area/volume (S A /V) ratio and catalytic ability of Pt metal, the sensing behaviors are efficiently improved owing to the smaller Pt NPs. A high sensing response of 5.81 under 1000 ppm NH 3 /air gas and a low detectable content of 1 ppm NH 3 /air are acquired at 275 ℃. In addition, a relatively fast sensing action with the response (recovery) times of 15 s (85 s) and 6 s (25 s) are observed upon exposure to 1000 and 1 ppm NH 3 /air gas, respectively, at 300 ℃. The Langmuir isotherm is used to study the related surface coverage under introduced ammonia gas. The proposed Pt NP/CeO 2 sensor shows prominent stability for long-term operation without intentional passivation treatment. The proposed sensor device’s benefits include a simple device structure, relatively easy manufacturing, a wide sensing range of ammonia gas content (1–1000 ppm NH 3 /air), and lower cost. • A new Pt NP/CeO 2 ammonia gas sensor was fabricated and well studied. • The Pt NP/CeO 2 -based sensor exhibited a response and a lower detectable level. • The Pt NP/CeO 2 -based sensor exhibited a relatively fast sensing action. • A wide detecting range on ammonia gas content and operating temperature for the Pt NP/CeO 2 -based sensor were acquired.

Colloidal MoS2 quantum dots for high-performance low power resistive memory devices with excellent temperature stability

Conventional memory technologies are facing enormous problems with downscaling, and are hence unable to fulfill the requirement of big data storage generated by a huge explosion of digital information. A resistive random access memory device (RRAM) is one of the most emerging technologies for next-generation computing data storage owing to its high-density stacking, ultrafast switching speed, high non-volatility, multilevel data storage, low power consumption, and simple device structure. In this work, colloidal MoS2 quantum dots (QDs) embedded in an insulating matrix of poly-(4vinylpyridine) (PVP) were used as an active layer to fabricate a RRAM device. The MoS2 QDs-PVP based RRAM device reveals an excellent nonvolatile resistive switching (RS) behavior with a maximum current on-off ratio (ION/IOFF) of 105. High endurance, long retention time, and successive “write-read-erase-read” cycles indicate high-performance RRAM characteristics. The ultimate power consumption by this RRAM device is considerably low for energy saving. In addition, the MoS2 QDs-PVP based device shows RS behavior even at 130 °C. High ION/IOFF, low operating power, high endurance, long retention time, and excellent stability with temperatures reveal that the MoS2 QDs-PVP based device can be a promising candidate for high-performance low power RRAM devices that can be operated at relatively higher temperatures.

Dot‐Product Operation in Crossbar Array Using a Self‐Rectifying Resistive Device

AbstractReducing computational complexity is essential in future computing systems for processing a large amount of unstructured data simultaneously. Dot‐product operations using crossbar array devices have attracted considerable attention owing to their simple device structure, intuitive operation scheme, and high computational efficiency of parallel operation. The resistive switching device is considered a promising candidate as the main data storage in the crossbar array owing to its highly reliable performance. In this study, a tri‐layer TaOx/Al2O3/Ti:SiOx‐based resistive switching device is proposed. The proposed device exhibits a high electrical selectivity of 2.5 × 105 based on the optimized biasing scheme, a stable non‐volatility, and reliable read disturbance characteristic of up to 108. Additionally, the device achieves high reading current of 1 µA and a low off‐leakage current of 1 pA, which favors the reliable characteristics in the data writing sequence and the dot‐product operation in the crossbar array device. Furthermore, the resistive switching mechanism based on the material and electrical conduction characteristics is analyzed. Lastly, the dot‐product operation in an 8 × 8 crossbar array is performed. As a result, the calculated and measured signal values in each column in the crossbar array of the device are found to be in good agreement.

46‐3: Invited Paper: Skin‐like Organic Optoelectronic System for Real‐time Heart Rate Monitoring

Conventional wearable electronics do not have conformal contact with the skin, so they might produce unreliable detecting of physiological signals during continuous health monitoring. This leads to the skin‐like healthcare patch that ensure secure contact with skin and maximizes user's comfort during daily life. Here, we present skin‐like stretchable and conformable healthcare patch in which stretchable organic light‐emitting diode (OLED) matrix display and a stretchable organic photoplethysmography (PPG) sensor are implemented together. The patch, fabricated on elastomer substrate without pre‐strained fabricating process, maintain stable operation up to 30% strain by the use of the stress relief layers and deformable micro‐cracked interconnects that reduce the mechanical stress of the OLED matrix display and PPG sensor. The simple device structure and reliable fabrication process show promise for commercialization of healthcare patch as novel form‐factor of wearable electronics.

18.55% Efficiency Polymer Solar Cells Based on a Small Molecule Acceptor with Alkylthienyl Outer Side Chains and a Low-Cost Polymer Donor PTQ10

18.55% Efficiency Polymer Solar Cells Based on a Small Molecule Acceptor with Alkylthienyl Outer Side Chains and a Low-Cost Polymer Donor PTQ10

Purely organic pyridium-based materials with thermally activated delayed fluorescence for orange-red light-emitting electrochemical cells

Light-emitting electrochemical cells (LECs) based on ionic transition metal complexes (iTMCs) have become a trend in the field of electroluminescence research due to their simple device structure. However, high cost has become a major obstacle to the development of these precious metal-containing materials. Addressing this challenge, two pyridium-based thermally activated delayed fluorescence (TADF) emitters were designed and synthesized to obtain high-efficiency orange-red-emitting light-emitting electrochemical cells (LECs). Pyridine moiety is used as the precursor of electron acceptor , as well as the embedded ionic part, connecting with different donors, carbazole ( CZ ) and tert -butyl carbazole ( tBuCZ ), named Pym-CZ and Pym-tBuCZ . The lifetime measurements showed delayed fluorescence at 2887 and 1746 ns for Pym-CZ and Pym-tBuCZ , respectively, confirming their TADF characteristics. The orange-red emission of Pym-CZ is considered to be due to the strong intermolecular interaction in high concentration, while green emission occurs when the molecules are in monomer form. Notably, compounds Pym-CZ and Pym-tBuCZ are the first pure ionic organic TADF materials for orange-red LECs, and the maximal EQE of LEC based on Pym-CZ reaches approximately 1.2%, demonstrating the potential of a new method for manufacturing low-cost orange-red LECs. • Two pyridium-based thermally activated delayed fluorescence (TADF) emitters were designed and synthesized to obtain high-efficiency orange-red-emitting light-emitting electrochemical cells (LECs). • The orange-red emission of Pym-CZ is considered to be due to the strong intermolecular interaction in high concentration, while green emission occurs when the molecules are in monomer form. • The maximal EQE of LEC based on Pym-CZ reaches approximately 1.2%.

Highly permeable WO3/CuWO4 heterostructure with 3D hierarchical porous structure for high-sensitive room-temperature visible-light driven gas sensor

Light-driven gas sensors that featured with simple device structure, intrinsic safety and room-temperature sensing characteristic have received increasing attention in recent years. However, it is still a great challenge for light-driven gas sensors to achieve high sensitivity due to the low utility of photo-generated carriers caused by the undesired recombination of carriers in the sensitive layer. Herein, a visible-light driven gas sensor based on hierarchical porous (HPS) WO 3 /CuWO 4 heterostructure with unique interconnected framework is developed. The gas sensor exhibits high sensitivity (R g /R a =82) to NO 2 (1 ppm) under visible-light illumination at room-temperature, which is 8.2, 12.6 and 3.5 times higher than the sensors based on pure HPS WO 3 , HPS CuWO 4 and WO 3 /CuWO 4 nanoparticles. On one hand, this exceptional high sensitivity is mainly derived from the low recombination of photo-generated carriers mediated by interfacial electric field effect of heterojunction, and on the other hand, the excellent sensing performance is related to the enhanced gas adsorption that endowed by the light irradiation and the rich reactive sites of the unique HPS structure of WO 3 /CuWO 4 . This study is expected to provide an important reference for designing other high-sensitive room-temperature light-driven gas sensors. • WO 3 /CuWO 4 heterostructure with 3D hierarchical porous structure (HPS) was prepared. • The sensor based on HPS WO 3 /CuWO 4 exhibited high sensitivity to NO 2 under visible-light. • Constructing HPS WO 3 /CuWO 4 can improve the separation efficiency of photo-generated charges. • The interconnected pore structure of HPS WO 3 /CuWO 4 facilitates the rapid penetration of gas molecules.

Producing p-Doped Surface for Hole Transporting Layer-Free Nonfullerene Organic Solar Cells.

Hole transporting layer-free organic solar cells with simplified device structures are desirable for their mass production. In this work, a p-dopant of organic molybdenum peroxide (OMP) to dope nonfullerene active layers to produce p-doped surface on the active layer is adopted. The OMP can effectively dope widely used polymer donors of nonfullerene organic solar cells, i.e., PTB7-Th, PBDB-T, and even PBDB-T-2F that has a very deep highest occupied molecular orbital (HOMO) energy level of -5.47eV. The doping mechanism lies in the strong oxidizing property of peroxide groups of the OMP leading to superior doping properties. In the end, hole transporting layer-free nonfullerene organic solar cells with the device structure of ITO/PEI-Zn/PBDB-T-2F:IT-4F/Ag are fabricated. The cells show a power conversion efficiency of 12.2% and good thermal stability.

N-Si/p-Sb2Se3 structure based simple solar cell device

Sb2Se3 is a p-type semiconductor that has been widely used as an absorber layer in thin film solar cells. For this study, Sb2Se3 was made using the solid-state reaction route, and thin films were deposited by the thermal evaporation method at room temperature and annealed at various temperatures. The crystallinity of Sb2Se3 thin films improved after annealing. The material and thin films were characterized by XRD, Raman, SEM, and UV–Vis spectroscopy to study their structural and optical properties. A simple device structure that can be made using a thermal evaporation system is proposed. We have accomplished simulation work based on Sb2Se3/c-Si hetero-junction photovoltaic cells using SCAPS-1D. In the simulation, experimental data of Sb2Se3, including its band gap, thickness, and absorption coefficient, have been introduced. The simulation is used to extract the parameters, such as back contact work function, electron affinity, and the thickness of the p-Sb2Se3 layer and n-Si layer, which is also varied and optimized to improve the device's performance. p-Sb2Se3 with a band gap of 1.64 eV showed a maximum efficiency of 12.75% at the optimized conditions. As n-Si is commercially available, this simple device structure can have multiple local applications. It can be considered a reliable method for predicting photovoltaic performance for future studies, such as improving the efficiency of Sb2Se3 solar cells or trying out a new tandem solar cell structure using Sb2Se3.

Semitransparent Organic Solar Cells with Efficiency Surpassing 15%

AbstractSemitransparent organic solar cells (ST‐OSCs) have promising prospects for building or vehicle integrated solar energy harvesting with energy generation and see‐through function. How to achieve both an adequate average visible transmittance (AVT) and high‐power conversion efficiency (PCE) is always the key issue. Herein, a simple but effective strategy for constructing high performance ST‐OSCs by introducing a small molecule [2‐(9‐H‐Carbazol‐9‐yl) ethyl] phosphonic acid (2PACz) into a low‐donor content active layer is reported. The fill factor is improved from 70.5% to 75.5% and correlated to the mitigated charge recombination and strengthened charge extraction, further ascribed to the enhanced build‐in potential, reduced charge transport resistance, and favorable film morphology. By combining the unique nature of 2PACz, that can spontaneously form in situ self‐organized hole transport interlayers under bulk‐heterojunction films, PEDOT‐free ST‐OSCs with a PCE of 15.2%, amongst the highest values in this field, is achieved with an AVT of 19.2%. Moreover, an outstanding light utilization efficiency of 3.39% is also obtained with an AVT of 30.0% and a PCE of 11.3% in a translucent device by tuning the electrode. The work demonstrates a new and simple strategy for achieving excellent AVT and PCE in ST‐OSCs with simplified device structure.

Giant Photoresponsivity and External Quantum Efficiency in a Contact‐Engineered Broadband a‐IGZO Phototransistor

AbstractBroadband photodetectors with a wide ultraviolet (UV)–visible (vis)–near‐infrared (NIR) spectral response reduce cost and form factors in smart sensing systems by using one rather than multiple devices for versatile applications. However, simultaneously achieving broadband detection, high responsivity, and fast response time remains challenging. This study demonstrates a high‐performance broadband amorphous In–Ga–Zn–O (a‐IGZO) phototransistor using an engineered Ni/Ti bilayer metal contact. This device differs drastically from the conventional a‐IGZO phototransistors in several aspects: 1) Pronounced photoresponse occurs at the device ON‐state rather than the OFF‐state. 2) A broadband response of 385–980 nm rather than a narrowband UV response. 3) Fast sub‐ms response time with no persistent photocurrent. 4) High responsivity of exceeding 105 A W−1. The external quantum efficiency exceeding 107% and specific detectivity exceeding 1015 Jones are also among the best of any UV–vis–NIR broadband photodetectors. The photoresponse is attributed to the light‐sensitive source–drain series resistance at the ON‐state. The Ni diffusion during postmetal annealing induces photoactive subgap states and modulates the conductivity of a‐IGZO at the contact region. The superior performance using low‐temperature processes and simple device structures as the widely available a‐IGZO technology suggests a tremendous application potential of this broadband phototransistor.

Power-Efficient Gas-Sensing and Synaptic Diodes Based on Lateral Pentacene/a-IGZO PN Junctions.

Function convergence of gas sensing and neuromorphic computing is attracting much research attention due to the promising potential in electronic olfactory, artificial intelligence, and internet of everything systems. However, the current neuromorphic gas-sensing systems are either realized via integration of gas detectors and neuromorphic devices or operating with three-terminal synaptic transistors at high voltages, leading to a rather high system complexity or power consumption. Herein, gas-modulated synaptic diodes with lateral structures are developed to converge sensing, processing, and storage functions into a single device. The lateral synaptic diode is based on a p-n junction of an organic semiconductor (OSC) and amorphous In-Ga-Zn-O, in which the upper OSC layer can directly interact with the gas molecules in the atmosphere. Typical synaptic behaviors triggered by ammonia, including inhibitory postsynaptic current and paired-pulse depression, are successfully demonstrated. Meanwhile, a low power consumption of 6.3 pJ per synaptic event has been achieved, which benefits from the simple device structure, the decent chemosensitivity of the OSC, and the low operation voltage. A simulated ammonia analysis in human exhaled breath is further conducted to explore the practical application of the synaptic diode. Therefore, this work provides a gas-modulated synaptic diode for circuit-compact and power-efficient artificial olfactory systems.

Protonated g-C3N4-based nonvolatile memories with good environmental robustness assisted by boron nitride

• Memory devices fabricated with protonated g-C 3 N 4 can exhibit enhanced memory performances, in which acid concentration is crucial. • g-C3N4 treated with 8 M HCl presents the best resistive switching performance, which might be relative to its texture without violent tortuosity. • The protonated g-C 3 N 4 -based memory devices present good environmental robustness, including temperature and ionizing irradiation. • The high tolerant temperature (454 °C) can also be enhanced by doping BN for heat dissipation. Memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit enhanced non-volatile bipolar switching performances and good environmental robustness. The searching for new memory that can work under harsh conditions will be significant for their application in some important fields such as geothermal, oil and aerospace industries. In this work, memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit non-volatile behaviors and bipolar switching characteristics. Protonation treatment can enhance the memory performance efficiently compared with un-protonized device. Among them, the device containing g-C 3 N 4 treated with 8 M HCl presents the best resistive switching performance with ON/OFF ratio of 10 4 and good retention capability, which might be relative to its texture without violent tortuosity. In addition, the protonated g-C 3 N 4 -based memory devices exhibit good environmental robustness, including temperature and ionizing irradiation. Specially, its high tolerant temperature (454 °C) can also be assisted by doping BN for heat dissipation. Their good thermal/irradiating stabilities are assigned to the strong bond energy of C N double bonds localized π-conjugated tri-s-triazine rings. In all, the facial protonation treatment without any functionalization or supporting, the simple sandwich device structure and good environmental robustness endow their promising applications in aerospace and outdoor environment.

Electrical and Low Frequency Noise Characterization of Graphene Chemical Sensor Devices Having Different Geometries.

Chemiresistive graphene sensors are promising for chemical sensing applications due to their simple device structure, high sensitivity, potential for miniaturization, low-cost, and fast response. In this work, we investigate the effect of (1) ZnO nanoparticle functionalization and (2) engineered defects onto graphene sensing channel on device resistance and low frequency electrical noise. The engineered defects of interest include 2D patterns of squares, stars, and circles and 1D patterns of slots parallel and transverse to the applied electric potential. The goal of this work is to determine which devices are best suited for chemical sensing applications. We find that, relative to pristine graphene devices, nanoparticle functionalization leads to reduced contact resistance but increased sheet resistance. In addition, functionalization lowers 1/f current noise on all but the uniform mesa device and the two devices with graphene strips parallel to carrier transport. The strongest correlations between noise and engineering defects, where normalized noise amplitude as a function of frequency f is described by a model of AN/fγ, are that γ increases with graphene area and contact area but decreases with device total perimeter, including internal features. We did not find evidence of a correlation between the scalar amplitude, AN, and the device channel geometries. In general, for a given device area, the least noise was observed on the least-etched device. These results will lead to an understanding of what features are needed to obtain the optimal device resistance and how to reduce the 1/f noise which will lead to improved sensor performance.

Molecular Engineering Enables TADF Emitters Well Suitable for Non‐Doped OLEDs with External Quantum Efficiency of Nearly 30%

AbstractNon‐doped organic light‐emitting diodes (OLEDs) are particularly appealing due to the merit of the extremely simple device structure. However, the performance of non‐doped OLEDs is usually far inferior than that of doped devices, mainly due to the lack of desirable emitters. An ideal emitter for non‐doped OLEDs should not merely be highly emissive in the host matrix but also be capable of delivering excellent properties in its condensed state. Herein, through molecular engineering, an “axial and equatorial carbazolyl extension” approach to manipulate the molecular packing behavior is developed, and thus, the emitter is awarded with superior properties in its neat film. Based on this approach, through simply modifying the conventional acridine donor in a thermally activated delayed fluorescence (TADF) emitter with carbazole moieties in the way of hyper‐conjugation, two new TADF emitters with the molecular skeleton being extended both horizontally and vertically by carbazole moieties are constructed. The resulted TADF emitters reveal superb properties with simultaneous excellent thermal and morphological stabilities, photophysical behaviors, and charge transporting ability in their neat film. Owing to the merits of these synergistic superior properties, highly efficient non‐doped green emissive OLED with the state‐of‐the‐art external quantum efficiency of nearly 30% is realized.

Hydrophilic carbon monoliths derived from metal-organic frameworks@resorcinol-formaldehyde resin for atmospheric water harvesting

Atmospheric water harvesting (AWH) is considered a promising technique to address the problem of global water shortage. Adsorption-based AWH technology, has the advantages of a simple device structure, high energy efficiency, wide application range, etc., and has attracted much attention. For the adsorption, one of the key issues is to find high-performance porous adsorbents. Porous carbons have exceptional stability, high porosity and low cost, but are usually highly hydrophobic with a low affinity for polar water molecules. A class of monolithic porous carbons with good hydrophilicity was prepared by the pyrolysis of composites consisting of a metal-organic framework in a resorcinol-formaldehyde resin matrix, in which the metal-organic parts developed polar sites in the final products. AWH tests showed that in a relative humidity of 40%-80%, the water capture capacity of the adsorbents reached 20 wt.%.