Carboxylated Carbon Nanotubes Research Articles

Enhanced cycling stability of silicon electrode for lithium-ion batteries by dual hydrogen bonding mediated by carboxylated carbon nanotube

Enhanced cycling stability of silicon electrode for lithium-ion batteries by dual hydrogen bonding mediated by carboxylated carbon nanotube

Balancing stretchability and conductivity: Carbon nanotube layer-enhanced non-ionic conductive hydrogels with a sandwich structure

In non-ionic conductive hydrogels, conductivity often conflicts with mechanical properties, posing a challenge in creating hydrogels that strike a balance between conductivity and mechanical properties. Here, we addressed this issue by integrating carboxylated carbon nanotube (CNT) layers in a sandwich structure onto the surface of the cationic hydrogel (P(AM-co-DMDAAC), PAD), followed by dehydration for densification. This approach simultaneously improved the conductivity of the hydrogel while maintaining its stretchability. The stability of the composite structure was ensured through electrostatic interactions, hydrogen bonding, and physical entanglement between the PAD hydrogel and the CNT layer. Additionally, adjusting the water–solid ratio of the hydrogel allows fine-tuning of its conductivity and stretchability. Remarkably, at a 500 % water–solid ratio, the hydrogel achieved a conductivity of 2.3 S/m. By further reducing the water content, the conductivity could be increased to 25 S/m, significantly higher than similar hydrogels. The PAD-CNT hydrogel found applications in swelling response, tunable resistance wires, and as strain sensors. Notably, the sandwich structure enables the PAD-CNT hydrogel to output capacitive signals, exhibiting a more sensitive response in monitoring human movement. Overall, this study introduces a novel composite structure for conductive hydrogels, holding tremendous potential in flexible conductivity and smart response fields.

Preparation of a V–COF@SWCNTs-COOH/SPCE supported molecularly imprinted electrochemical sensor for real-time detection of trace sulfadimidine

To overcome the limitations of insufficient sensitivity and poor specificity of portable screen-printed carbon electrode-electrochemical sensors (SPCE-EC) in practical applications, we prepared carrier composites of carboxylic single-walled carbon nanotubes vertically grafted by covalent organic frameworks (v-COF@SWCNTs-COOH) and coated with a molecularly imprinted polymer (MIP) of sulfadimidine (SM2). 55 °C hot steam elution is more eco-friendly than traditional organic solvent elution. The results showed that when the mass ratio of DBA to DBA-SWCNTs was 1:1, the v-COF@SWCNTs-COOH obtained by the two-step synthesis method could increase the electrical signal up to 2.33-fold of the bare electrode. The bifunctional monomer MIP prepared on the above structure enhanced the signal response by 2.91-fold, with a high imprint factor of 20. The assembled MIP/v-COF@SWCNTs-COOH/SPCE were analyzed by differential pulse voltammetry (DPV) with a high sensitivity of 0.21 nM for LOD and 0.70 nM for LOQ. In milk and fish samples, the recovery rate was 95.0 %–104.8 %. The validation of authentic pork samples with the statutory LC-MS/MS method showed no significant difference (P > 0.05). The sensor's performance indicators remained robust after five repeated uses. Therefore, the MIP/v-COF@SWCNTs-COOH/SPCE combines the cheapness and portability of SPCE, while the sensitivity and specificity of small molecule detection were significantly improved.

Hydrogen-Bonded Organic Framework Enhanced Antifouling Property for Efficient In Situ Electrochemical Assay of Cerebral Ascorbic Acid.

Accurate determination of cerebral ascorbic acid (AA) is crucial for understanding ischemic stroke (IS) related pathological events. Carbon fiber microelectrodes (CFEs) have proven to be robust tools with high sensitivity toward AA, however, they face ongoing challenges for in situ measurement due to the non-specific adsorption of proteins in brain tissue. In this study, the hydrogen-bonded organic framework PFC-71 is synthesized and modified on CFEs through π-π stacking interactions with carboxylated carbon nanotubes (CNT-COOH). It is found that the gating effect and hydrophilicity of PFC-71 provided the CFE with excellent antibiofouling properties. As a result, AA exhibited a low oxidation potential of -30mV on the CFE/CNT-COOH/PFC-71, even in the presence of 20mgmL-1 bovine serum albumin. Given the structural advantages of CFE/CNT-COOH/PFC-71, a ratiometric electrochemical strategy for AA is established, enabling the in situ assay of cerebral AA in a middle cerebral artery occlusion (MCAO) model with high accuracy and stability.

Carboxyl carbon nanotubes strengthened tailorable chitosan imprinted polymers for selective adsorption of dibenzothiophene in hydrogenated diesel

Selectively capturing and adsorbing high-valued dibenzothiophene (DBT) from hydrogenated diesel is a meaningful and economic tactic for sulfide resource recovery. The design of efficient adsorbents with desirable adsorption capacity, high selectivity and simple retrieval is still challenging. In this work, an imprinting polymerization coupling freeze-drying approach was adopted to elaborately prepare carboxyl carbon nanotubes (CCNT) strengthened chitosan (CS) molecularly imprinted polymers (MIPs-CCNT/CS) for non-destructive adsorption of DBT. The introduction of CCNT into CS-based imprinted matrix improved thermal and mechanical stability and enriched adsorption sites of MIPs-CCNT/CS, thus enhancing DBT adsorption ability with the maximum adsorption capacity of 30.58 ± 1.24 mg/g under the optimized adsorption conditions. The Langmuir isotherm and pseudo-second-order kinetics models were verified to fit satisfactorily with the adsorption procedures of MIPs-CCNT/CS towards DBT. Benefiting from the presence of plentiful DBT imprinted cavities, MIPs-CCNT/CS maintained a superior recognition for DBT in the quaternary stimulated diesel, and the relative selectivity coefficients of DBT for benzothiophene (BT), indole, and fluorene with respect to the control non-imprinted adsorbent (NIPs-CCNT/CS) were 2.19, 2.34, and 2.10, respectively. After six adsorption–desorption experiments, the adsorption capacity of MIPs-CCNT/CS toward DBT remained stable (20.67 ± 0.53 mg/g). The preliminary exploration for actual hydrogenated diesel demonstrated that MIPs-CCNT/CS has benign industrial application prospect in the separation and recycling of high value-added DBT.

Synthesis and application of MgCuAl-layered triple hydroxide/carboxylated carbon nanotubes/bentonite nanocomposite for the effective removal of lead from contaminated water

A novel multicomponent adsorbent nano-composite was synthesized by intercalating bentonite clay and carboxylated carbon nanotubes (CNT-COOH) into MgCuAl-layered triple hydroxide (MgCuAl-LTH), abbreviated as LTH/CNT-COOH/Bent. The produced nano-composite, its parental materials, and their binary combinations were characterized using various techniques. Pore filling was noted based on the BET analysis, hence, indicating effective component integration in the nano-composite structure. Further, distinct peaks appearing on the FTIR and XRD spectra of the single materials also appeared on the synthesized composites (including the binary combinations of the parental materials), hence, further indicating the successful synthesis of the targeted adsorbents. The effects of process parameters including pH, adsorbent dose, lead initial concentration and contact time on lead removal, were explored. In general, the application of LTH/CNT-COOH/Bent adsorbent yielded a significant improvement in lead adsorption capacity (∼260.8 mg/g) relative to all parental materials and their binary combinations. It was revealed that the adsorbent dose and lead initial concentration are the most significant factors affecting lead uptake onto the synthesized adsorbent and the adsorption kinetics was fast. The obtained results indicated that the Avrami kinetic and Redlich-Peterson isotherm models best fit the lead adsorption kinetics and isotherm experimental results, respectively. Furthermore, the response surface methodology (RSM) technique was employed for optimization of lead removal, achieving near complete removal (>99 %) at LTH/CNT-COOH/Bent dose of 0.5 g/L, lead initial concentration of 40 ppm and a time of 2 h. Additionally, the machine learning (ML) and the ANN based models for lead removal using LTH/CNT-COOH/Bent nano-composite yielded good predictions.

Optimization Design of the Multidimensional Heterostructure toward Lightweight, Broadband, Highly Efficient, and Flame-Retarding Electromagnetic Wave-Absorbing Composites.

A novel multidimensional electromagnetic wave-absorbing material was developed by combining carboxylated carbon nanotubes (CNT) with graphene oxide (GO) through multidimensional design, and cobalt/nickel-based metal organic frameworks (Co/Ni-MOF) were subsequently loaded onto the GO surface via its rich functional groups to form the composite absorbing material CNT-rGO-Co/Ni-MOF. Incorporating 25 wt % of CNT-rGO-Co/Ni-MOF into the paraffin matrix led to a remarkable RLmin value of -43 dB at 16.4 GHz, with an effective absorbing bandwidth (EAB) exceeding 4 GHz, all within a thickness of just 1.5 mm, showcasing its "lightweight, broadband, and high efficiency" characteristics. The exceptional electromagnetic wave absorption performance was attributed to multi-interface polarization loss, resistance loss, and magnetic medium loss. Furthermore, when incorporating 10 wt % of CNT-rGO-Co/Ni-MOF, the heat release capacity and peak heat release rate of EP/CNT-rGO-Co/Ni-MOF10 decreased by 59.2 and 52.6%, respectively.

Spray-coated PDA-wrapped carboxylic CNT/PES membrane to augment fouling mitigation, organic removal, and membrane stability in electrochemical membrane filtration

This study introduces robust and conductive polydopamine (PDA)-wrapped carboxylic carbon nanotube (C-CNT)-coated polyethersulfone (PES) membrane for electrochemical membrane filtration to treat greywater. Self-polymerized dopamine was prepared directly under oxidative conditions on the CNT strands, followed by their immobilizations on the surface of the PES membrane through a novel spray-coating technique. The spraying coating technique improved both the durability of the coating layer and membrane permeability by 27 % higher than that prepared by the conventional vacuum filtration method. The spraying coating technique enhanced the electroactive properties of the PDA/C-CNT membrane so that the fouling rate was reduced more effectively than the C-CNT membrane or bare PES membrane. Fouling mitigation of the PDA/C-CNT membrane was attributed to the combined effect of electrostatic repulsions between the foulants and the conductive membrane surface along with degradation of organic compounds by electrochemical oxidation. The constant current density profile also confirmed the structural stability of the conductive layer on the membrane under both cathodic and anodic conditions. Furthermore, the fouling layer formed by membrane filtration was removed effectively by in-situ anodic cleaning. Over 80% of water permeability was recovered without losing the membrane integrity up to 3 consecutive anodic cleaning cycles.

Ultrasensitive electrochemical sensing for simultaneous rapid detection of zearalenone and ochratoxin A in feedstuffs and foodstuffs

Mycotoxins are causing persistent worries regarding food safety worldwide due to their ability to elicit a wide range of harmful effects in both animals and humans. Approaches that can identify a single mycotoxin are not sufficient for addressing the needs of quality control of agricultural products since they are often co-contaminated by multiple mycotoxins. This paper presents the development of an electrochemical sensor that is free of biomolecules and is capable of simultaneously detecting zearalenone (ZEN) and ochratoxin A (OTA) through the incorporation of nickel oxide (NiO) with carboxylated carbon nanotubes (MWCNT(–COOH)).This is the first time that NiO–MWCNT(–COOH) based electrochemical sensor has achieved the simultaneous potential-resolved selective detection of ZEN and OTA. Under optimized conditions, good linear responses were observed in the range of 0.01–10.24 μg mL−1 for ZEN and 0.04–10.24 μg mL−1 for OTA with low detection limit of 6 and 15 ng mL−1, respectively. The proposed electrochemical sensor demonstrated good selectivity, reusability, reproducibility, and shelf-life for the sensitive detection of both mycotoxins. Moreover, the sensor was made utilizing screen-printing technology to demonstrate its potential for commercialization and practical application. Our biomolecule-free electrochemical sensor was successful in evaluating these mycotoxins in actual samples of corn flour and wheat flour, proving its promising application in monitoring ZEN and OTA co-contamination in agricultural products.

Flexible BTO piezoelectric generator fabricated by hydrothermal method with the assistance of lignocellulose and carbon nanomaterials

It is of great significance to develop piezoelectric composites with mechanical flexibility and high electromechanical coupling characteristics for the collection and conversion of mechanical energy. In this work, a barium titanate (BTO) based piezoelectric composite was prepared by hydrothermal synthesis and high-temperature carbonization with the assistance of cellulose nanofibers (CNF), graphene oxide (GO) and carboxylated carbon nanotubes (C-CNT). C-CNT, GO and CNF can provide growth sites for BTO, but compared with C-CNT, CNF and GO have stronger interaction with BTO, which can improve the compatibility between BTO and CNF/polyvinylidene fluoride (PVDF) matrix. The tensile strength of the composite membrane prepared by GO-CNF-BTO treated at 1100 °C can reach 23.36 ± 8.30 MPa. After further hot pressing and polarization treatment, its longitudinal piezoelectric coefficient (d33) reaches 9.8 ± 2.6 pC·N−1. Correspondingly, the open-circuit voltage (VOC) and short-circuit current (ISC) increases to 11.64 V and 824 nA, respectively. In addition, the assembled piezoelectric generator (PEG) can charge for small commercial capacitors, as well as light small bulbs and electronic screens. It also has good piezoelectric output stability and sensing performance, which can effectively convert the mechanical energy from human motion into electrical energy. This work provides a reference for the performance improvement of flexible piezoelectric devices.

Effects of Carbon Nanotubes on Mechanical Strength, Damage Process, and Microstructure of Lithium Tailing Backfilling.

In this study, common multiwalled and carboxylated carbon nanotubes (CNTs) were added to the cemented lithium tailings backfill (CLTB). The effects of CNTs on the mechanical properties, hydration products, damage process, and microstructure of CLTB specimens were studied by uniaxial compression (UCS), infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The experimental results show that the addition of CNTs effectively increased the compressive strength compared with the blank control group. When the concentration was 0.05-0.20%, the compressive strength was proportional to the content, the optimal addition amount was 0.2%, and the enhancement effect was 75% and 95.31%, respectively. The FT-IR results indicate that the addition of CNTs increased the total amount of the hydration product but did not affect its type. The hydration of the three-dimensional reciprocal penetration network formed by moderate amounts of CNTs has a positive effect on the mechanical strength of CLTB specimens.

Ultrafast Fenton-like reaction using a peroxymonosulfate-mediated confined-Fe0 catalyst for the degradation of sulfamethoxazole

Herein, a nanoconfinement strategy was employed to encapsulate nano zero-valent iron (confined-Fe0) for the rapid degradation of sulfamethoxazole (SMX) through a peroxymonosulfate (PMS)-mediated Fenton-like reaction. The confined-Fe0 catalyst was synthesized in situ using a liquid-phase reduction method, incorporating nitrilotriacetic acid (NA) modified carboxylated carbon nanotube (FOC-N-6). Comprehensive experimental analyses and characterizations demonstrated the FOC-N-6 catalyst facilitated rapid electron transfer through the carbon framework and the surface PMS reactive complex (FOC-N-6-PMS*). This process accelerated the Fe(III)/Fe(II) redox cycle and promoted the formation of surface Fe(II) active sites (Fe0-OCNT-COOFe(II)-), which served as dominant adsorption sites for PMS. Density functional theory (DFT) calculations revealed that the confined-Fe0 structure can decrease the adsorption energy (Eads) of PMS on the FOC-N-6 surface. And the FOC-N-6-PMS* facilitated the rapid degradation of SMX through both non-radical and radical pathways. This confined-Fe0 catalytic strategy holds promise as a viable method for controlling emerging contaminants.

Highly compressible porous polyethyleneimine/chitosan composite aerogel with excellent mechanical properties as wide detection range sensors for human motion monitoring

AbstractBiomass three‐dimensional composite aerogels have garnered significant attention in the realm of wearable electronic skin owing to their favorable properties, including excellent human compatibility, environmentally benign degradability, and continuous porous architecture. However, conventional biomass aerogels suffer from inadequate mechanical flexibility, susceptibility to irreversible deformation under high compressive stress, and limited reusability, thereby constraining their applicability in sensing technologies. To address these limitations, this study presents the development of porous CCS/KH560/PEI/CNT‐COOH (CKPC) composite aerogels through a freeze–drying process. Chemical crosslinking was achieved using silane coupling agent (KH560) with carboxymethyl chitosan (CCS) and polyethyleneimine (PEI), while carboxylated carbon nanotubes (CNT‐COOH) were incorporated as conductive fillers. This approach successfully overcame the issues of poor mechanical properties, low elasticity, and unbalanced sensitivity‐sensing range trade‐off in chitosan‐based aerogel sensors. The results revealed that the porous CKPC aerogels exhibited a remarkable mechanical compressive strain of 86.3% while maintaining structural integrity post‐unloading. The CKPC composite aerogel‐based sensor demonstrated a high sensitivity of 42.9 within a wide strain range of 60%–76.3%, accompanied by a stable and repeatable electrical signal response across varying strains. The porous structure of the CKPC conductive aerogel sensor holds promising applications in human motion monitoring and flexible electronics.

Effect of seawater corrosion on the mechanical properties of basalt fiber reinforced polymer composites modified by silane coupling agent KH560 and carboxylated carbon nanotubes

Basalt fiber reinforced composite (BFRP) has been widely used in various engineering fields, while the corrosion resistance of BFRP in harsh environments needs to be improved. In this work, the effects of seawater corrosion on mechanical properties of silane coupling agent (KH560) and carboxylated carbon nanotubes (CNTs) modified basalt fiber reinforced epoxy resin composites (BF/EP) were studied by simulating seawater corrosion under different conditions. The results showed that with the increase in corrosion time and temperature, the flexural performance and interlaminar shear strength (ILSS) of the composite material significantly decreased. Under the same corrosion conditions, the modified basalt fiber composite has better corrosion resistance to seawater than the untreated one due to an enhanced "soft-rigid" multi-scale stress transfer region between the BF and resin matrix. The flexural strength, flexural modulus and ILSS of modified basalt fiber composites decreased by 17.7 %, 12.2 % and 11.3 %, respectively, after 7 weeks of seawater corrosion at 60 °C, while that of untreated basalt fiber composites decreased by 28.2 %, 20.4 % and 19.7 %, respectively. In addition, the corrosion of distilled water on basalt fiber composites was also studied. Similarly, the modified basalt fiber composites showed better corrosion resistance to distilled water compared to the untreated basalt fiber composites. The research shows that the synergistic modification of KH560 and CNTs can effectively improve the corrosion resistance of BF/EP. This work is significant for promoting the development of BFRP and its application in marine environment.

Aminated reduced graphene oxide-carbon nanotube composite gas sensors for ammonia recognition

Composites based on carbon nanomaterials exhibit many advantageous properties for gas sensing, such as high and fast response, room-temperature operation, and tailoring sensitivity by energy level engineering. However, only the first attempts to employ such chemosensors for gas-sensing applications have been made. In this work, an on-chip multisensor array of carboxylated carbon nanotubes (CNT), aminated reduced graphene oxide (rGO-Am), and CNT/rGO-Am nanocomposite was fabricated using a simple and low-cost spray deposition method. The CNT/rGO-Am sensor demonstrated a fast and high response to NH3 in dry air at low (25 ppm) and high (400 ppm) concentrations of 70 and 115 %, respectively. The response to NH3 in humid air increased and reached 160 % at 400 ppm. The chemosensor exhibited high sensitivity and selectivity toward ammonia with a low detection limit estimated to be below 0.2 ppb. Linear discriminant analysis of the sensor responses to different concentrations of NH3, dry and humid air revealed better discrimination when CNT/rGO-Am composites were used in combination with CNT and rGO-Am sensors in an array. This study demonstrates that composite sensors with junctions between carbon nanomaterials have great potential for practical applications in fast and selective gas detection at room temperature and different humidity.

Durable and highly signal-stable pressure sensors prepared by sequential thiol-acrylate click reactions

Pressure sensors are an important part of the Internet of Things (IoT) and human–machine interaction (HMI), and their signal stability and durability are greatly affected by the interfacial interaction between the substrate and the conductive layer. Herein, a pressure sensor prepared by sequential radical-mediated thiol-acrylate click reactions is reported. In first click reaction, the porous substrate polyHIPE-SH with inherently thiols is fabricated. Those thiols give us second chance to chemically bridge carboxylic carbon nanotubes (CNT)/polyethylene glycol diacrylate (PEGDA) conductive coating to the substrate using the click reaction, with 21.5 % of the thiols on the substrate involved in the reaction. As expected, the obtained pressure-sensitive material CNT/PEGDA@polyHIPE-SH has a strong interfacial interaction between the substrate and the conductive layer, thus ensuring the good signal stability and durability. The sensor also has a sensitivity of up to −6.45 % kPa−1 and a wide response range from 0 to 400 kPa. Furthermore, the sensors are used as input devices to realize multi-mode HMI, and high-accuracy object recognition at low sensor densities via a convolutional neural network based deep learning model.

Touch–based potentiometric sensors for simultaneous detection of urea and ammonium from fingertip sweat

Urea is a biomarker for diagnosis and management of multiple disorders. The measurement of urea could help in the diagnosis of patients with kidney dysfunction. Despite their attractive analytical performances, the existing urea measurement methods are still limited to sophisticated and time–consuming or require invasive blood sampling. Herein, a reliable noninvasive, simple, and disposable touch–based potentiometric sensor is fabricated for rapid monitoring of fingertip sweat urea. Novel touch–based urea detection relies on immobilized urease recognition and a solid–contact ammonium–ion–selective electrode, along with a screen–printed carbon working electrode modified carboxylated carbon nanotubes for enhancing sensor’s sensitivity. The fingertip sweat under sedentary rest conditions can be instantaneously collected on customized porous polyvinyl alcohol hydrogel transporting sweat to working electrode surface where the hydrolysis of urea is catalyzed, generating bicarbonate and ammonium. The resulting ammonium can be detected with ion–selective transducer, enabling indirect monitoring of sweat urea. Potential interference from co–existing ammonium in human sweat is addressed by developing a dual disposable potentiometric sensor, consisting of urea and ammonium sensors on a single strip platform allowing for simultaneous touch–based detection of sweat urea and ammonium. The resulting dual disposable sensing system offers rapid urea and ammonium monitoring within a group of healthy human subjects, along with a good correlation with R2 = 0.974 between the sweat urea and capillary blood urea levels. Additional confirmation among a broad sample of individuals along with the validation of sensor data through centralized laboratory tests will establish the practicality of simultaneously monitoring urea and ammonium levels.

Ultrasensitive electrochemical detection of bile acids via ZIF-67-MOF-derived CoNi(OH)x/CeO2/COOH-MWCNTs composite electrodes

Fast and ultra-sensitive assays are essential for the assessment of the efficacy of traditional Chinese medicines. Here, an ultrasensitive and rapid electrochemical detection of bile acid in traditional Chinese medicine using composite electrodes is presented. Cobalt-nickel hydroxide and cerium dioxide (CoNi(OH)x/CeO2) nanomaterials were synthesized in situ by a two-step reflux method with cobalt-containing metal–organic framework (ZIF-67), as precursor. It was ultrasonically complexed with carboxylated carbon nanotubes (COOH-MWCNTs) to form CoNi(OH)x/CeO2/COOH-MWCNTs composites, for facile direct detection of bile acids in traditional Chinese medicine. Characterization methods were used to verify the successful creation of the composite CoNi(OH)x/CeO2/COOH-MWCNTs, a material which demonstrated excellent electrochemical properties. The experimental results showed that the electrode responded well when bile acids, nicotinamide adenine dinucleotide, and 3α hydroxysteroid dehydrogenase were simultaneously present in the solution, and that the peak current had a good linear relationship (R2 = 0.988) with the concentration of bile acids (0.05–10.0 µM). The sensor has an outstanding detection limit of 1.0 nM, 2–3 orders of magnitude more sensitive than the concentration. Therefore, it can be used for rapid on-site detection of bile acids in real traditional Chinese medicines.

3D porous conductive matrix based on phase-transited BSA and covalent coupling-stabilized transition ZnS-CNT for antifouling and on-site detection of nitrite in soil

Nitrite plays a critical role in a variety of nitrification and denitrification processes in the nitrogen cycle. Due to the high surface energy, tendency to aggregate, and poor conductivity, current nitrite ZnS-based sensing platform could not meet the need of on-site nitrite detection in smart agriculture. In order to address these issues, the carboxylated carbon nanotube (CNT) was introduced to reduce the surface energy and prevented aggregation of ZnS, while ZnS-carboxylated CNT (ZnS-CNT) composite also provided excellent electrochemical conductivity. Furthermore, the introduction of phase transition BSA (PTB) created a three-dimensional porous conductive matrix without interfering with the mass transfer process of nitrite. The resulting sensing platform exhibited a linear detection range of 10 nM to 0.4 mM for nitrite, with a detection limit of 0.73 nM. And this sensing platform had the excellent antifouling ability to direct detection nitrite in real soil suspension. In addition, the sensing platform demonstrated remarkable resistance to interferences from pH variations, microbial presence, and organic pollutants that usually present in soil environment. Therefore, on-site detection of nitrite ions in soil environment was realized no needing complex pretreatments.

Ultrastrong and Reusable Solar‒Thermal‒Electric Generators by Economical Starch Vitrimers.

In frigid regions, it is imperative to possess functionality materials that are ultrastrong, reusable, and economical, providing self-generated heat and electricity. One promising solution is a solar‒thermal‒electric (STE) generator, composed of solar‒thermal conversion phase change composites (PCCs) and temperature-difference power-generation-sheets. However, the existing PCCs face challenges with conflicting requirements for solar‒thermal conversion efficiency and mechanical robustness, mainly due to monotonous functionalized aerogel framework. Herein, a novel starch vitrimer aerogel is proposed that incorporates orientational distributed carboxylated carbon nanotubes (CCNT) to create PCC. This innovative design integrates large through-holes, mechanical robustness, and superior solar‒thermal conversion. Remarkably, PCC with only 0.8 wt.% CCNT loading achieves 85.8MPa compressive strength, 102.4°C at 200mW cm-2 irradiation with an impressive 92.9% solar-thermal conversion efficiency. Noteworthy, the STE generator assembled with PCC harvests 99.1W m-2 output power density, surpassing other reported STE generators. Strikingly, even under harsh conditions of -10°C and 10mW cm‒2 irradiation, the STE generator maintains 20°C for PCC with 325mV output voltage and 45mA current, showcasing enhanced electricity generation in colder environments. This study introduces a groundbreaking STE generator, paving the way for self-sufficient heat and electricity supply in cold regions.