Applications In Portable Devices Research Articles

Internal Integrated Temperature Sensor for Lithium-Ion Batteries.

Lithium-ion batteries represent a significant component of the field of energy storage, with a diverse range of applications in consumer electronics, portable devices, and numerous other fields. In view of the growing concerns about the safety of batteries, it is of the utmost importance to develop a sensor that is capable of accurately monitoring the internal temperature of lithium-ion batteries. External sensors are subject to the necessity for additional space and ancillary equipment. Moreover, external sensors cannot accurately measure internal battery temperature due to packaging material interference, causing a temperature discrepancy between the interior and surface. Consequently, this study presents an integrated temperature sensor within the battery, based on PT1000 resistance temperature detector (RTD). The sensor is integrated with the anode via a flexible printed circuit (FPC), simplifying the assembly process. The PT1000 RTD microsensor's temperature is linearly related to resistance (R = 3.71T + 1003.86). It measures about 15 °C temperature difference inside/outside the battery. On short-circuit, the battery's internal temperature rises to 27 °C in 10 s and 32 °C in 20 s, measured by the sensor. A battery with the PT1000 sensor retains 89.8% capacity under 2 C, similar to the normal battery. Furthermore, a PT1000 temperature array sensor was designed and employed to enable precise monitoring and localization of internal temperature variations.

Cardioattentionnet: advancing ECG beat characterization with a high-accuracy and portable deep learning model.

The risk of mortality associated with cardiac arrhythmias is considerable, and their diagnosis presents significant challenges, often resulting in misdiagnosis. This situation highlights the necessity for an automated, efficient, and real-time detection method aimed at enhancing diagnostic accuracy and improving patient outcomes. The present study is centered on the development of a portable deep learning model for the detection of arrhythmias via electrocardiogram (ECG) signals, referred to as CardioAttentionNet (CANet). CANet integrates Bi-directional Long Short-Term Memory (BiLSTM) networks, Multi-head Attention mechanisms, and Depthwise Separable Convolution, thereby facilitating its application in portable devices for early diagnosis. The architecture of CANet allows for effective processing of extended ECG patterns and detailed feature extraction without a substantial increase in model size. Empirical results indicate that CANet outperformed traditional models in terms of predictive performance and stability, as confirmed by comprehensive cross-validation. The model demonstrated exceptional capabilities in detecting cardiac arrhythmias, surpassing existing models in both cross-validation and external testing scenarios. Specifically, CANet achieved high accuracy in classifying various arrhythmic events, with the following accuracies reported for different categories: Normal (97.37 ± 0.30%), Supraventricular (98.09 ± 0.25%), Ventricular (92.92 ± 0.09%), Atrial Fibrillation (99.07 ± 0.13%), and Unclassified arrhythmias (99.68 ± 0.06%). In external evaluations, CANet attained an average accuracy of 94.41%, with the area under the curve (AUC) for each category exceeding 99%, thereby demonstrating its substantial clinical applicability and significant advancements over traditional models. The deep learning model proposed in this study has the potential to enhance the accuracy of early diagnosis for various types of arrhythmias. Looking ahead, this technology is anticipated to provide improved medical services for patients with heart disease through continuous, non-invasive monitoring and timely intervention.

Diagnoses of postpartum urinary retention using next-generation non-piezo ultrasound technology: assessing the accuracy and benefits

Postpartum urinary retention has a wide range of publicized incidences, likely caused by frequent misdiagnosis of this puerperal complication. Especially covert postpartum urinary retention has a high number of missed diagnoses due to the lack of symptoms and the time-extensive diagnostics via ultrasound, leading to no treatment and no appropriate follow-up. To simplify the diagnosis and establish a screening tool we analyzed the application of portable handheld-ultrasound devices (PUD) as used in Point-of-care diagnostics in comparison to established standard ultrasound devices (SUD). This prospective study aimed to evaluate the reliability of non-piezo, chip-based PUD in comparison to the measurement withSUD, containing a piezo transducer, as golden standard for the ultrasound diagnosis of postpartum urinary retention. Randomly, 100 participants between the first and seventh day after delivery in an obstetric ward underwent ultrasound examinations using a EPIQ 5 W (Philips) as SUD and a Butterfly iQ (Butterfly Network) as PUD to compare the accuracy in bladder size after micturition and the estimated post-void residual volume. Intraclass correlation coefficients, Bland-Altman plots, and Pearson correlation coefficients were used for analyzing the reliability and agreement between the measurements of these devices and were calculated for subgroups as body mass index, mode of delivery and timepoint of delivery. The results show a near-perfect agreement (0.994) and correlation (r = 0.982) for estimated post-void residual volume and for most measurements between the two types of ultrasound devices. The agreement rate for the diagnosis of covert postpartum urinary retention is 100%. Subgroup analyses lack a significant difference reflected by agreement and correlation rates. These findings affirm the high reliability of PUD for the diagnosis of postpartum urinary retention and supports their integration into daily clinical practice, thereby simplifying regular controls of the bladder by physicians during daily rounds on the ward. This technology may allow a higher diagnosis rate so that patient care can be optimized and the long-term impact on continence and quality of life can be studied and analysed.

Heterostructure Design of Amorphous Vanadium Oxides@Carbon/Graphene Nanoplates Boosts Improved Capacity, Cycling Stability and High Rate Performance for Zn2+ Storage

AbstractAs a promising power supplier, flexible aqueous zinc ion batteries (AZIBs) have drawn great attention and been demonstrated potential applications in portable electronic devices, yet their capacity, stability, and rate performance are severely limited by cathode materials. Herein, a spontaneous encapsulation and in situ phase transformation strategy is proposed for the construction of heterostructured amorphous vanadium oxide@carbon/graphene (A‐VOx@C/G) nanoplates as highly stable and efficient cathode materials for Zn2+ storage. In this design, A‐VOx provides abundant active sites with rapid ion diffusion channels and robust tolerance against ion insertion/extraction, while N‐doped carbon encapsulation and interlaced graphene network ensure efficient electron transfer. The mechanisms respectively for phase transformation during electrochemical amorphization and charge storage during cycling are investigated in detail. The as‐prepared A‐VOx@C/G achieves an outstanding electrochemical performance with 429 mAh g−1 at 0.5 A g−1, 73% retained at 20 A g−1 (315 mAh g−1), and excellent stability over 2000 cycles at 20 A g−1 (91% retention). Moreover, quasi‐solid‐state AZIBs assembled from A‐VOx@C/G cathode exhibit high flexibility and can sustain large mechanical deformation without performance degradation. It is believed that this study provides a guideline toward designing high‐performance cathode materials for AZIBs through structure optimization.

Advances in the Application of Lithium-Rich Oxide Materials in Lithium-ion Battery Cathodes

With the rapid growth of global energy demand and the increasing awareness of environmental protection, the development of efficient, safe, and environmentally friendly energy storage systems has become one of the hotspots in today's science and technology fields. Lithium-ion batteries (LIBs) have shown great potential for application in portable electronic devices, electric vehicles, and large-scale energy storage due to their high energy density, low self-discharge rate, and long cycle life. However, with the continuous technological advancement and expanding market, the requirements for the performance of LIBs are increasing, especially in terms of energy density and cycle stability. Li-rich oxides as cathode materials for Li-ion batteries are not only capable of releasing a large amount of lithium ions during charging, providing a much higher specific capacity than traditional cathode materials, but also have less reactive oxygen involved in the reaction in their layered structure, which helps to maintain the cycling stability and average operating voltage of the materials, thus extending the service life of the batteries and improving the overall performance. In this paper, we first explore the effects of the layered and disordered structures in the crystal structure of Li-rich oxides on the performance of LIBs. Then, the paper summarizes the problems of Li-rich oxides. Finally, two methods, ion doping, and surface capping, are proposed to improve the performance of Li-rich oxides.

Fe3N/Fe3O4 hetero-nanocrystals embedded in porous carbon fibers for enhanced lithium storage.

Energy storage devices have applications in large-scale portable and smart devices due to their high energy density and long lifespan, but the limited theoretical capacity of the graphite anode in lithium-ion batteries has slowed the development of portable electronic devices. Herein, we prepared porous fibers with heterogeneous Fe3N/Fe3O4 nanocrystals wrapped by a carbon layer. A series of measurements, such as TEM images, Raman spectra, XRD pattern and XPS analysis, were used to unveil the formation of Fe3N/Fe3O4 nanocrystals. Due to the synergistic effect of the large specific surface area originating from the porous structure and the heterogeneous nanocrystals, the porous Fe3N/Fe3O4@C fibers exhibit a good electron/ion transmission route and rich active sites. As anode materials for lithium-ion batteries (LIBs), porous Fe3N/Fe3O4@C fibers delivered a reversible capacity of 964 mA h g-1 after 200 cycles at 2 A g-1 and long-term cycling stability (282 mA h g-1 after 2000 cycles at 5 A g-1). This work provides a method to regulate biphasic anode materials with desirable structures to enhance the reversibility of LIBs.

Recovered graphene-hydrogel nanocomposites for multi-modal human motion recognition via optimized triboelectrification and machine learning

Hydrogels have extensive applications in portable, flexible, wearable, and self-powered electronic devices based on triboelectric nanogenerators (TENGs). An important issue with hydrogels is their tendency to dehydrate over time, which leads to a decline in both ionic conductivity and mechanical flexibility. Furthermore, the current techniques used to produce these hydrogels mostly rely on the freeze–thaw process, which has limited ability to modify the polymer conformation. Herein, a novel water-assisted recovered hydrogel is proposed using a simple strategy to prepare high-performance hydrogel-based TENGs by optimizing the cross-linking and crystalline domains. Synthesis of the electrostatic electrode in the TENG involved the incorporation of polyethylene oxide (PEO) into a polyvinyl alcohol (PVA) hydrogel network via cross-linking. Graphene nanoplatelets (GNP) were added to precisely tune the electrical conductivity. GNP constructs the backbone structures in the hydrogel and enhances the charge transport capacity. Electrical conductivity is changed by the GNP concentration and thus, electrical output of the hydrogel can be facilely controlled. The water reabsorption increased density and crystallinity of the cross-linking and allowed the hydrogel to show superior performance compared to the original one. The 7th recovery hydrogel produced around 594 V, 40 μA, and 32 nC. The 7th recovery hydrogel had exceptional endurance, with the capacity to withstand over 16,000 cycles of contact separation. Moreover, it could be stretched up to 541 % of its original length and improved by almost twice as much as that without the recovery process. By combining multi-modal graphene-based TENG sensors with machine learning, a state-of-the-art behavioral monitoring system was created that could reliably detect tapping fingers with an average accuracy rate of 95 %. The findings of this research will pave the way for new approaches to the development of autonomous motion sensors and flexible renewable energy sources.

Bilayering Enables Faster Charging and High Areal Capacity of Na-Ion Electrodes

Sodium-ion batteries (NIBs) are a promising alternative to lithium-ion batteries (LIBs), which currently dominate electric vehicle and portable device applications. But while NIBs have potential cost and safety advantages, they still lag behind LIBs in capacity, power output and longevity. Considerable research and development effort is now being expended to develop more energy-dense electrodes in order for NIBs to become commercially viable.A possible route to increasing the energy density of NIBs is to increase electrode thickness (and therefore areal capacity), from presently used ~50 μm to 100 - 150 μm. However, achieving this in practice is limited by multiple factors related to manufacturing and rate performance of thicker electrodes. Slot-die coating is the dominant manufacturing process for electrodes, which involves mixing of active material, conductive additive, binder and solvent, coating the resulting slurry onto current collecting foil, and drying. The drying step places a practical limit on the dried thickness, as it is accompanied by binder migration away from the current collector, potentially reducing the adhesion and mechanical strength of the electrode. As a result, the maximum thickness of electrodes in industry is typically constrained to 50 - 90 µm. Furthermore, given the mobility of Na ions in the electrolyte in the torturous electrode pore network is normally restricted, thicker electrodes undergo greater polarisation and capacity loss as C-rate (current density) is increased. This means thicker electrodes cannot be charged/discharged quickly without detriment to energy density.Here we present a novel bilayer architecture of Na-ion positive electrodes obtained through slurry casting two successive sub-layers of different active materials: sodium manganese oxide (Na0.7MnO2, NMO) and sodium vanadium phosphate (Na3V2(PO4)3, NVP). The bilayer electrodes are 100 µm thick with high areal loading of ≈17 mg/cm2, which might normally be expected to inhibit high-rate performance. As expected, for low current densities < 1C ≡ 45 mA/gcm2, the charge capacity of the bilayer cathodes is similar and comparable to a simple, homogeneous (i.e. random) mixture of the two active materials, regardless of how the sub-layers are arranged. However, at 2C and 3C, overall electrode capacity is revealed to be sensitive to the microstructural arrangement, such as the relative position of NMO and NVP sub-layers. There is a significant increase in retained capacity when the NMO sub-layer is on the current collector. In order to understand the sensitivity of overall capacity to structural arrangement, simulations were performed that are formulated in a way to capture the designed microstructural heterogeneity of the electrodes. The simulations show the complex interaction between the voltage-capacity profile of the active material, the relative position of the sub-layer, and the evolution of Na ion gradients through the thickness of the electrode. In the most favourable arrangement, the dispersion of local overpotential due to local concentration polarization effects is reduced, which in turn enables greater utilization of the active materials. The sensitivity of sub-layer position is shown to relate to the significant difference in voltage-capacity profiles of NMO and NVP. Differences in charge-transfer resistance, electrical conductivity, and ionic mobility within the two materials also have a role in how the critical Na ion concentration profile evolves through the charge/discharge cycle.We discuss how the concept of layered or other types of structured electrode might be applied to Na ion batteries, and to what extent these effects might increase the competitiveness of Na ion batteries compared with their more established LIB counterparts. Figure 1

Study on the Deflagration Characteristics and Application of Portable Gas Pulse Ash Cleaning Devices

Study on the Deflagration Characteristics and Application of Portable Gas Pulse Ash Cleaning Devices

Low Power Gas Sensors: From Structure to Application.

Gas sensors are pivotal across industries, encompassing environmental monitoring, industrial safety, and healthcare. Recently, a surge in demand for low power gas sensors has emerged, driven by the huge need for applications in portable devices, wireless sensor networks, and the Internet of things (IoT). The practical realization of a densely interconnected sensor network demands gas sensors to have low power consumption for energy-efficient operation. This Perspective offers a comprehensive overview of the progress of low-power sensors for gas and volatile organic compound detection, with a keen focus on the interplay between sensing materials (including metal oxide semiconductors, metal-organic frameworks, and two-dimensional materials), sensor structures, and power consumption. The main gas sensing mechanisms are discussed, and we delve into the mechanisms for achieving low power consumption including material properties and sensor design. Furthermore, typical applications of low power gas sensors are also presented, including wearable technology, food safety, and environmental monitoring. The review will end by discussing some open questions and ongoing needs.

Integration of Pre‐Activated Carbon‐Fabric Layers for Ampere‐Hour‐Scale Quasi‐Solid‐State Pouch‐Type Zinc–Air Batteries

AbstractAchieving ampere‐hour‐scale capacities in pouch‐type zinc–air batteries (ZABs) requires optimizing key factors, such as preventing inactive ZnO dendrite formation on zinc anodes and enhancing catalytic activity with efficient gas diffusion in the air cathode. Here, a pioneering flexible, large‐area, ampere‐hour‐scale quasi‐solid‐state ZAB is introduced, addressing these challenges through a novel preactivation strategy combined with a layered assembly approach. This method employs mass‐producible fibrous carbon textiles to form flexible fabrics that separate functions within multi‐stacked layers. Preactivated carbon fabric layers, independently functionalized and easily reassembled, enhance scalability and manufacturability. A bilayer catalytic air electrode, incorporating hydrophilic NiFe hydroxide and hydrophobic FeNC regions, ensures efficient charge and mass transfer, significantly boosting catalytic activity. To prevent dendrite formation on the zinc anode, a zincophilic copper interlayer is implemented. This configuration supports rapid, stable charge–discharge cycles at a high current density of 20 mA cm⁻2. The large‐area stacked bipolar structure pouch cells, exceeding 36 cm2, achieve a discharge capacity of up to 2500 mAh, maintaining high cycle stability through discharge–charge cycles with 200 mAh per cycle. This approach significantly enhances the scalability, manufacturability, and production potential of ultrahigh‐capacity wearable ZABs, making them practical for widespread application in various portable and flexible devices.

Iron phosphides nanoparticles strongly coupled to N-doped carbon for high-efficiency oxygen reduction and evolution

Constructing composite structures is an effective strategy for tailoring the electronic configuration and balances the adsorption/desorption capability of oxygen-containing intermediates for obtaining high-performance bifunctional catalysts. Herein, an in-situ pyrolysis strategy was used to construct Fe2P nanoparticles supported on N-doped carbon (Fe2P/NC) catalyst. The DFT indicated that the catalytic activity of the as-prepared catalyst is significantly increased by the strong electronic interaction between the Fe2P nanoparticles and the nitrogen-doped carbon, which endows the catalyst with fast electron transfer capability and optimizes the free energy between the catalyst and the adsorbed intermediate, as well as the d-band center of the material. The as-synthesized Fe2P/NC has a low potential gap ΔE (ΔE = Ej=10 – E1/2) of ca. 0.75 V, a specific capacity as high as 833 mAh·gZn−1 and cycling stability for 1320 cycles at the current density of 10 mA·cm−2. Such a synthesis strategy provides an effective route to realizing applications for portable electronic Zn-air battery-related devices.

Accordion-Structured Hydrogel Battery Capable of Maintaining Ion Gradients for Extended Periods.

Inspired by the electric eel, biomimetic, biocompatible energy storage, and power generation technologies show promise for applications in portable and wearable electronic devices by mimicking the electric cell tandem structure of the electric eel and utilizing ionic gradients between hydrogel compartments to generate electricity. Previously, inspired by the unique morphology of the torpedo fish, an artificial flexible power source that can output a large current was introduced. This power source uses a hydrogel-infused paper hybrid to create, accordionize, and reconfigure arbitrary-sized gel films in series and parallel, and the power output of the flexible battery was significantly enhanced. However, maintaining the ionic gradient of hydrogel batteries during storage remains a challenge. Here, by borrowing the isolation properties of the accordion structure, we propose a unique paper accordion structure design to fabricate an Accordion-Structured Hydrogel Battery (ASHB). Pretreatment of hydrogel-injected paper strips improved storage stability and maintained the ionic gradient of hydrogel cells in the nonworking state, so that the cell's gradient retention time after the assembly is completed is increased by at least 30 h compared to stacking, and its per-cell operating voltage is still able to reach. The design also makes the assembly and use of flexible batteries more modular and holistic. In the future, it may be possible to power the cells with ions generated by the human body or the metabolites of living organisms, leading to the development of more efficient, sustainable, and eco-friendly power solutions.

A piezoelectric human motion energy harvester with stress amplification mechanism

The kinetic energy is rich in human walking, which may be exploited to provide sustainable energy for portable and miniaturized devices by properly design of the energy harvester. In order to effectively amplify the actual force on the piezoelectric material upon the external load, a beam-shaped piezoelectric energy harvester (PEH) is designed. The PEH is prepared by embedding poly(vinylidene fluoride) (PVDF) piezoelectric strips into the compression zone of the beam. The underlying mechanism is discussed via mechanical theoretical modeling and finite element simulation. It is demonstrated that the actual integrated force on the piezoelectric film of PVDF is about 31.7 times that of the external force applied on the beam’s mid-span. The study would pave the way for force amplification mechanism in designing PEHs and holds promises for portable device applications.

Room-Temperature Flexible CNT/Fe2O3 Film Sensor for ppb-Level H2S Detection.

Carbon nanotubes (CNTs) had room temperature response, large surface area, and excellent mechanical properties, making them favorable for the design of flexible, wearable, and portable gas sensors. However, CNTs were lacking in response and selective response to different gases, such as H2S. Here, we demonstrated a flexible H2S ppb-level gas sensor based on a carbon nanotube/amorphous Fe2O3 (CNT/Fe2O3) film at room temperature, which was fabricated via a simple one-step solvent-thermal method. The CNT/Fe2O3 film gas sensor exhibited a high selective response to H2S (with a response of 55.1% to 100 ppb H2S), rapid reversible response at room temperature (with a response time of ∼127 s to 100 ppb H2S), and low limit of detection to about 2 ppb. Additionally, the CNT/Fe2O3 film maintained good sensing performance under various bending conditions and could be further fabricated into the fiber gas sensor device via wet stretching, retaining response at the ppb level (with a response of 18.6% to 100 ppb H2S). This research on a flexible gas sensor device based on the CNT film/fiber opened up new possibilities for wearable portable electronic device applications.

Electrocatalytic efficiency of carbon nitride supported gold nanoparticle based sensor for iodide and cysteine detection

Extensive investigations are being conducted on gold nanoparticles focusing on their applications in biosensors, laser phototherapy, targeted drug delivery and bioimaging utilizing advanced detection techniques. In this work, an electrochemical sensor was developed based on graphite carbon nitride supported gold nanoparticles. Carbon nitride supported gold nanoparticles (Au–CN) was synthesized by applying a deposition-precipitation route followed by a chemical reduction technique. The composite system was characterized by X-ray diffraction and X-ray photo electron spectroscopy methods. Electron microscopy analysis confirmed the formation of gold nanoparticles within the size range of 5–15 nm on the carbon nitride support. Carbon nitride supported gold based sensor was employed for the electrochemical detection of iodide ion and l-cysteine. The limit of detection and sensitivity of the sensor was attained 8.9 μM and 0.96 μAμM⁻1cm⁻2, respectively, for iodide ion, while 0.48 μM and 5.8 μAμM⁻1cm⁻2, respectively, was achieved for the recognition of cysteine. Furthermore, a paper-based electrochemical device was developed using the Au–CN hybrid system that exhibited promising results in detecting iodide ions, highlighting its potential for economic and portable device applications.

MXene/Zwitterionic Hydrogel Oriented Anti‐freezing and High‐Performance Zinc–Ion Hybrid Supercapacitor

AbstractWith the wide application of portable electronic devices, zinc–ion hybrid supercapacitors (ZIHCs) have aroused great interest. However, balancing the low‐temperature performance and high energy density of ZIHCs remains a huge challenge. Herein, a zwitterionic hydrogel electrolyte (ZHE) loaded with carboxymethylcellulose and MXene is designed for ZIHCs, which shows excellent frost resistance and high output voltage. Carboxymethylcellulose and MXene enhance the flexibility and conductivity of the zwitterionic hydrogel electrolyte. Moreover, When ZnCl2 is introduced into a gel electrolyte, it induces an increase in the rate of ion transport, which enables a broadening of the operating temperature of the hydrogel (−40 °C–25 °C). As a result, Zn//AC ZIHCs based on ZHE show a high voltage window of 2 V, a high energy density (specific capacity) of 137 Wh kg−1 (247 F g−1), and the potential for wearable devices. This study will provide an effective strategy for the design of hydrogel ZIHCs with wide voltage windows, high energy density, and high practicality.

Evaluation of the Mechanical Properties of PLA Material Used For 3D Printing Solar E-Hub Component

The advent of additive manufacturing (AM) technologies revolutionized design and production processes across various industries. In renewable energy, AM enabled new possibilities for optimizing solar e-hub (solar energy harvesting module) configurations, enhancing efficiency and performance. This study examined critical considerations such as material selection, durability, and cost-effectiveness in solar hub development. This fast-prototyping technique was controlled by computer-aided design (CAD) software like CREO Parametric 7.0 and Creality Slicer 4.8. Experimental results indicated that PLA (Polylactic acid) materials exhibited superior strength, with an impact energy of 4.8 Joules. The deformation study revealed that the maximum load of 22 MPa aligned with the ultimate tensile strength of PLA, and a hardness test result of 83.1 HRF featured its exemplary hardness properties. These findings advanced the understanding of using AM to investigate mechanical behaviours of PLA materials and optimize solar e-hub configurations for portable device applications, promoting sustainable energy solutions and the adoption of renewable energy technologies. In addition, the successful implementation of this approach will enable the renewable energy sectors to minimize the carbon foot-prints towards helping the global net-zero emissions by aligning the circular economy approach.

Optimizing power output in direct formic acid fuel cells using palladium film mediation: experimental and DFT studies

Low-temperature hydrogen production from environmentally friendly liquid fuels such as methanol, ethanol, and formic acid for miniature fuel cells used in powering portable electronic devices is attracting reasonable attention. In this study, we present the findings from the decomposition of formic acid and subsequent power generation within a microfluid fuel cell. The fuel cell system was engineered to incorporate a palladium membrane at the anode and a modified carbon Torray paper at the cathode. To assess fuel cell performance, we employed chronopotentiometry and cyclic voltammetric electro­chemical techniques. This simple fuel cell could achieve a current peak of 3.17 µW by utilizing 2.50 M HCOOH solution and 2.26 µW with 0.1 M solution, all at room temperature. Finally, to provide a deeper understanding of the reactivity and HCOOH decomposition pathways on various palladium surfaces, we conducted density functional theory (DFT) studies. Our DFT investigations revealed that the Pd(111) surface exhibited more negative adsorption energy compared to other surfaces, suggesting its propensity for a more isomeric crystal morphology. This research underscores the promising potential of low-temperature hydrogen production using safe liquid fuels in microfuel cell applications for portable electronic devices.

High‐Performance Flexible PbS Nanofilm Wavelength Sensor with Detection Region Ranging from DUV to NIR

AbstractIn this study, on the fabrication of a flexible wavelength sensor is reported, which is achieved by growing a layer of lead sulfide (PbS) nanofilm on both sides of a polyethylene terephthalate substrate using the chemical bath deposition method, followed by the deposition of two parallel Au interdigital electrodes. Experimental result shows that the photocurrent ratio of the two photodetectors monotonically decreases with increasing wavelength in the range from 265 nm (UV) to 2000 nm (NIR), indicating that the incident light wavelength can be distinguished by the photocurrent ratio. Notably, the as‐constructed wavelength sensor exhibits superior performance compared to most previously reported filter‐less designs, achieving an average absolute error of 11.5 nm and an average relative error of 1.1%. It is also found that the sensor exhibits excellent mechanical flexibility and environmental stability. Furthermore, by introducing the back‐end circuit, real‐time detection of the wavelength of monochromatic light and the peak wavelength of LED light are achieved, with detection errors not exceeding 2.8% and 2.6%, respectively. It is believed that the flexible PbS nanofilm wavelength sensor prepared in this study has potential application in future portable and flexible optoelectronic devices.