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1.
Neurosci Biobehav Rev ; 161: 105682, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38642865

RESUMEN

Long-term high altitudes (HA) exposure's impact on cognition has yielded inconsistent findings in previous research. To address this, we conducted a meta-analysis of 49 studies (6191 individuals) to comprehensively evaluate this effect. Moderating factors such as cognitive task type, altitude (1500-2500 m, 2500-4000 m, and above 4000 m), residential type (chronic and lifelong), adaptation level and demographic factors were analyzed. Cognitive tasks were classified into eight categories: perceptual processes, psychomotor function, long-term memory, working memory, inhibitory control, problem-solving, language, and others. Results revealed a moderate negative effect of HA on cognitive performance (g = -.40, SE =.18, 95% CI = -.76 to -.05). Psychomotor function and long-term memory notably experience the most pronounced decline, while working memory and language skills show moderate decreases due to HA exposure. However, perceptual processes, inhibitory control, and problem-solving abilities remain unaffected. Moreover, residing at altitudes above 4000 m and being a HA immigrant are associated with significant cognitive impairment. In summary, our findings indicate a selective adaptation of cognitive performance to HA conditions.


Asunto(s)
Altitud , Cognición , Humanos , Cognición/fisiología , Memoria a Corto Plazo/fisiología
2.
J Exp Child Psychol ; 242: 105907, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38513328

RESUMEN

Intuitive statistical inferences refer to making inferences about uncertain events based on limited probabilistic information, which is crucial for both human and non-human species' survival and reproduction. Previous research found that 7- and 8-year-old children failed in intuitive statistical inference tasks after heuristic strategies had been controlled. However, few studies systematically explored children's heuristic strategies of intuitive statistical inferences and their potential numerical underpinnings. In the current research, Experiment 1 (N = 81) examined 7- to 10-year-olds' use of different types of heuristic strategies; results revealed that children relied more on focusing on the absolute number strategy. Experiment 2 (N = 99) and Experiment 3 (N = 94) added continuous-format stimuli to examine whether 7- and 8-year-olds could make genuine intuitive statistical inferences instead of heuristics. Results revealed that both 7- and 8-year-olds and 9- and 10-year-olds performed better in intuitive statistical inference tasks with continuous-format stimuli, even after focusing on the absolute number strategy had been controlled. The results across the three experiments preliminarily hinted that the ratio processing system might rely on the approximate number system. Future research could clarify what specific numerical processing mechanism may be used and how it might support children's statistical intuitions.


Asunto(s)
Heurística , Intuición , Humanos , Incertidumbre
3.
Nanomicro Lett ; 15(1): 149, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37286913

RESUMEN

Human metabolite moisture detection is important in health monitoring and non-invasive diagnosis. However, ultra-sensitive quantitative extraction of respiration information in real-time remains a great challenge. Herein, chemiresistors based on imine-linked covalent organic framework (COF) films with dual-active sites are fabricated to address this issue, which demonstrates an amplified humidity-sensing signal performance. By regulation of monomers and functional groups, these COF films can be pre-engineered to achieve high response, wide detection range, fast response, and recovery time. Under the condition of relative humidity ranging from 13 to 98%, the COFTAPB-DHTA film-based humidity sensor exhibits outstanding humidity sensing performance with an expanded response value of 390 times. Furthermore, the response values of the COF film-based sensor are highly linear to the relative humidity in the range below 60%, reflecting a quantitative sensing mechanism at the molecular level. Based on the dual-site adsorption of the (-C=N-) and (C-N) stretching vibrations, the reversible tautomerism induced by hydrogen bonding with water molecules is demonstrated to be the main intrinsic mechanism for this effective humidity detection. In addition, the synthesized COF films can be further exploited to effectively detect human nasal and oral breathing as well as fabric permeability, which will inspire novel designs for effective humidity-detection devices.

4.
Affect Sci ; 4(2): 413-428, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37304566

RESUMEN

The relation between empathy and morality is a widely discussed topic. However, previous discussions mainly focused on whether and how empathy influences moral cognition and moral behaviors, with limited attention to the reverse influence of morality on empathy. This review summarized how morality influences empathy by drawing together a number of hitherto scattered studies illustrating the influence of targets' moral characteristics on empathy. To explain why empathy is morally selective, we discuss its ultimate cause, to increase survival rates, and five proximate causes based on similarity, affective bonds, the appraisal of deservingness, dehumanization, and potential group membership. To explain how empathy becomes morally selective, we consider three different pathways (automatic, regulative, and mixed) based on previous findings. Finally, we discuss future directions, including the reverse influence of selective empathy on moral cognition, the moral selectivity of positive empathy, and the role of selective empathy in selective helping and third-party punishment.

5.
Nanomaterials (Basel) ; 13(10)2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37242076

RESUMEN

Two-dimensional (2D) phthalocyanine-based covalent organic frameworks (COFs) provide an ideal platform for efficient and rapid gas sensing-this can be attributed to their regular structure, moderate conductivity, and a large number of scalable metal active centers. However, there remains a need to explore structural modification strategies for optimizing the sluggish desorption process caused by the extensive porosity and strong adsorption effect of metal sites. Herein, we reported a 2D bimetallic phthalocyanine-based COF (COF-CuNiPc) as chemiresistive gas sensors that exhibited a high gas-sensing performance to nitrogen dioxide (NO2). Bimetallic COF-CuNiPc with an asymmetric synergistic effect achieves a fast adsorption/desorption process to NO2. It is demonstrated that the COF-CuNiPc can detect 50 ppb NO2 with a recovery time of 7 s assisted by ultraviolet illumination. Compared with single-metal phthalocyanine-based COFs (COF-CuPc and COF-NiPc), the bimetallic structure of COF-CuNiPc can provide a proper band gap to interact with NO2 gas molecules. The CuNiPc heterometallic active site expands the overlap of d-orbitals, and the optimized electronic arrangement accelerates the adsorption/desorption processes. The concept of a synergistic effect enabled by bimetallic phthalocyanines in this work can provide an innovative direction to design high-performance chemiresistive gas sensors.

6.
R Soc Open Sci ; 10(4): 220957, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37035292

RESUMEN

We explore individual differences in tiger personality. We first asked-is there evidence of personality dimensions (analogous to the Big Five in human personality research) in the Amur tiger? We then asked, are any discoverable personality dimensions associated with measured outcomes, including group status, health and mating frequency? 152 of our participating tigers live in the world's largest semi-wild tiger sanctuary in North Eastern China. Our second sample of 96 tigers also lives in a sanctuary. Having two samples allowed us to assess the replicability of the personality dimensions or factors reported in our first sample. We found that two factors (explaining 21% and 17% of the variance among items) which we call, for descriptive ease, Majesty and Steadiness, provide the best fit to the data. Tigers that score higher on Majesty are healthier, eat more live prey, have higher group status (among other tigers as assessed by human raters) and mate more often. We provide some ethological context to put flesh on the quantitative bones of our findings concerning these magnificent and charismatic animals.

7.
Psychon Bull Rev ; 30(5): 1740-1758, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37101097

RESUMEN

Theory of mind (ToM) represents a complex ability, while persons with autism spectrum disorder (ASD) encounter difficulties in the processing of ToM. The present ToM-focused studies on adults with ASD report inconsistent results, possibly owing to the differences between tasks. For instance, different ToM-related tasks involve different cognitive abilities, but the development of these cognitive abilities is different among adults with ASD, thereby leading to different behaviors by the same individual with ASD in different tasks. Therefore, it is of vital significance to explore the potential reasons for inconsistencies in the existing studies based on the task classification perspective. Hence, this study primarily reviews the existing ToM tasks used in studies on adults with ASD; afterward, based on the forms and characteristics of the task, the current ToM tasks are classified into four categories-reading comprehension, perceptual scene comprehension, comprehensive scene comprehension , and self-other processing. Subsequently, a meta-analysis is undertaken to determine the difference in each ToM task category between the ASD group and the typically developing (TD) group. As a result, 110 research papers (including 3,205 adults with ASD and 3,675 TD adults) that fulfilled the stated criteria are examined in this study. The study findings suggest that adults with ASD demonstrate worse performance in terms of all four ToM task categories as compared to TD adults. Furthermore, compared with tasks of self-other processing and perceptual scene comprehension, adults with ASD perform worse in reading comprehension and comprehensive scene comprehension. This shows that the differences between tasks may exert a potential influence on the study results. Future studies should focus on different abilities involved in ToM processing and the choice of ToM tasks, in order to elucidate the critical problems of ToM in adults with ASD.


Asunto(s)
Trastorno del Espectro Autista , Teoría de la Mente , Humanos , Trastorno del Espectro Autista/psicología , Cognición , Comprensión
8.
ACS Sens ; 8(1): 103-113, 2023 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-36635889

RESUMEN

Flexible chemiresistive gas sensors have attracted growing interest due to their capability in real-time and rapid detection of gas. However, the performance of gas sensors has long been hindered by the poor charge transfer ability between the conventional metal electrode and gas sensing semiconductors. Herein, for the first time, a fully flexible paper-based gas sensor integrated with the Ti3C2Tx-MXene nonmetallic electrode and the Ti3C2Tx/WS2 gas sensing film was designed to form Ohmic contact and Schottky heterojunction in a single gas sensing channel. Ti3C2Tx/WS2 has outstanding physical and chemical properties for both Ti3C2Tx and WS2 nanoflakes, showing high conductivity, effective charge transfer, and abundant active sites for gas sensing. The response of the gas sensor to NO2 (1 ppm) at room temperature is 15.2%, which is about 3.2 and 76.0 times as high as that of the Au interdigital electrode integrated with the Ti3C2Tx/WS2 sensor (4.8%) and the MXene electrode integrated with the Ti3C2Tx sensor (0.2%), respectively. Besides, this design performed at a limit of detection with 11.0 ppb NO2 gas and displayed excellent stability under high humidities. Based on first-principles density functional theory calculation results, the improvement of the gas sensing performance can be mainly attributed to the heterojunction regulation effect, work function matching, and suppressing metal-induced gap states. This work provides a new approach for the design of flexible gas sensors on paper with MXene-based conductive electrodes and gas sensing materials.


Asunto(s)
Dióxido de Nitrógeno , Temperatura , Conductividad Eléctrica , Electrodos
9.
Nanotechnology ; 34(17)2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36689767

RESUMEN

To increase the specific capacitance of supercapacitors, polyaniline (PANI) has been chosen as additive electrode material for the pseudocapacitive performance. Here, we synthesize a molecular-level uniform reduced graphene oxide/PANI (rGO/PANI) composite film with high flexibility and conductivity via self-assembly and specific thermal reduction, which performs great potential in flexible supercapacitors with high areal capacitance. Particularly, the electrode of rGO/PANI-42.9% exhibits a high specific areal capacitance (1826 mF cm-2at 0.2 mA cm-2), and it also presents a good cycling stability (it remains 76% of its initial capacitance after 10 500 cycles). Moreover, the specific gravimetric capacitance of rGO/PANI-33.3% reaches up to 256.4 F g-1at 0.2 A g-1, showing greatly enhanced performance compared with the pure rGO electrode (183 F g-1). The results of various characteristic analysis demonstrate that electrochemical performance of the as-prepared rGO/PANI film is closely associated with the uniform distribution of PANI in rGO/PANI composite. Overall, our reported method is convenient and environmental-friendly, and could be beneficial for the development of high-performance capacitive energy storage materials.

10.
J Res Adolesc ; 33(2): 431-446, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36414409

RESUMEN

Mind wandering refers to task-unrelated thoughts that can interfere with ongoing tasks and could be sleep-driven across childhood. The present study investigated the mechanisms of the association between early adolescents' sleep and mind wandering with emotional symptoms and executive function as potential mediators. A total of 257 early adolescents (baseline aged 9-13 years old; 131 boys) completed the questionnaires consisting of the Pittsburgh Sleep Quality Index, mind wandering, depression and anxiety symptoms, and executive function. Cross-sectional and longitudinal data revealed a sequential mediation pathway of emotional symptoms and executive function in the association between sleep and mind wandering. The mediating effect of emotional symptoms in the link between sleep quality and mind wandering was significant among boys but not girls.


Asunto(s)
Atención , Función Ejecutiva , Masculino , Humanos , Adolescente , Niño , Estudios Transversales , Sueño , Encuestas y Cuestionarios
11.
Dev Sci ; 26(2): e13310, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36039023

RESUMEN

Previous findings on the association between theory of mind (ToM) and aggression in children are mixed. The social skills deficit view regarded ToM as a single-edged sword and proposed that a lack of ToM can lead to aggression, while the double-edged sword view proposed that children with advanced ToM can still show much aggression because children can also leverage ToM to harm others. To resolve the dispute between the two views, we conducted a meta-analysis combining cross-sectional and longitudinal findings from 53 studies including a total of 11,579 children aged between 2 and 15 years. The overall negative correlation between ToM and aggression was small but significant (r = -0.08). The negative correlation was robust, with the magnitude of the correlation being similar across physical versus relational aggression, proactive versus reactive aggression, cognitive versus affective ToM, preschoolers versus school-aged children, different aggression measurements, and different levels of societal individualism. Moreover, the negative correlation was found regardless of whether ToM and aggression were measured concurrently or at different time points, but the correlation was the largest when ToM was measured before aggression. Whether the aggression was bullying or not also moderated the association, with ToM only being negatively related to non-bullying aggression but not bullying. Together, these findings suggest that ToM is a single-edged sword to decrease general aggression and that aggression might also give rise to lower ToM capacity during development. RESEARCH HIGHLIGHTS: This study systemically reviewed the existing mixed findings on the association between aggression and ToM during childhood using a meta-analysis. There was a negative correlation between ToM and aggression in children aged between 2 and 15 years. The negative correlation between aggression and ToM was stronger when ToM was measured first, followed by aggression, than vice versa. There was a negative correlation between non-bullying aggression and ToM, whereas there was no correlation between bullying and ToM.


Asunto(s)
Acoso Escolar , Teoría de la Mente , Humanos , Niño , Preescolar , Adolescente , Estudios Transversales , Agresión/psicología , Habilidades Sociales
12.
Bioact Mater ; 19: 499-510, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35600976

RESUMEN

Existing strategies for bone defect repair are difficult to monitor. Smart scaffold materials that can quantify the efficiency of new bone formation are important for bone regeneration and monitoring. Carbon nanotubes (CNT) have promising bioactivity and electrical conductivity. In this study, a noninvasive and intelligent monitoring scaffold was prepared for bone regeneration and monitoring by integrating carboxylated CNT into chemically cross-linked carboxymethyl chitosan hydrogel. CNT scaffold (0.5% w/v) demonstrated improved mechanical properties with good biocompatibility and electrochemical responsiveness. Cyclic voltammetry and electrochemical impedance spectroscopy of CNT scaffold responded sensitively to seed cell differentiation degree in both cellular and animal levels. Interestingly, the CNT scaffold could make up the easy deactivation shortfall of bone morphogenetic protein 2 by sustainably enhancing stem cell osteogenic differentiation and new bone tissue formation through CNT roles. This research provides new ideas for the development of noninvasive and electrochemically responsive bioactive scaffolds, marking an important step in the development of intelligent tissue engineering.

13.
Behav Sci (Basel) ; 14(1)2023 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-38247669

RESUMEN

Parental burnout refers to exhaustion caused by the parenting role. This devastating negative emotion can have repercussions for adolescent social development. Nevertheless, much remains unclear about the association between parental burnout and adolescent prosocial behavior and the potential mechanisms underlying this relationship. Based on theoretical and empirical evidence, the current study examined the relationship between parental burnout and adolescent prosocial behavior by using a sequential mediation model that included both parental empathy and adolescent empathy as potential mediators. A total of 488 parent-adolescent dyads (for adolescents: 45.7% men, 54.3% women, Mage = 15.28 ± 1.67 years; for parents: 36.5% fathers, 63.5% mothers, Mage = 41.30 ± 3.79 years) completed questionnaires regarding demographics, social desirability, parental burnout, parental empathy, adolescent empathy, and adolescent prosocial behavior. After controlling for demographic covariates and social desirability, the results showed that parental burnout had a negative effect on adolescent-reported prosocial behavior through parental cognitive empathy and adolescent other-oriented empathy (adolescent cognitive empathy and empathic concern) sequentially. These findings contribute to our understanding of the role of parental burnout as a family environmental factor detrimental to the positive functioning of adolescents through parental reactions to their children's emotions and children's own social competence.

14.
J Happiness Stud ; 23(8): 3843-3864, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36187718

RESUMEN

The present work examines how culture and age interact to influence self-continuity and life satisfaction. Specifically, we compared Canadian and Chinese young (17-26 years old) and older adults (60-88 years old) in their sense of self-continuity and life satisfaction (N = 424). Consistent with past research, older adults reported greater self-continuity compared to their young counterparts, while cross-cultural comparisons showed that young Chinese reported greater self-continuity than young Canadians. In terms of life satisfaction, older adults again scored higher than younger adults, while cross-cultural comparisons indicated that, this time, young Canadians reported higher life satisfaction than young Chinese. Although the data were cross-sectional, indirect effects analyses showed that self-continuity mediated the effect of age on life satisfaction in both cultural groups, with the indirect effect stronger among Canadians than among Chinese. These findings highlight the importance of considering culture and age when examining psychological outcomes, and the potential of self-continuity as a mechanism to enhance overall life satisfaction.

15.
ACS Appl Mater Interfaces ; 14(38): 43628-43636, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36108153

RESUMEN

Single-walled carbon nanotubes (SWCNTs) are considered to be promising candidates for next-generation near-infrared (NIR) photodetectors due to their extraordinary electrical and optical properties. However, the low separation efficiency of photogenerated carriers limits the full utilization of the potential of pristine SWCNTs as photoactive materials. Herein, we report a novel high-performance visible-NIR SWCNT-based photodetector via interfacial charge-transfer-induced improvement by Au nanoparticle (AuNP) surface doping. Under 1064 nm light illumination, the as-fabricated AuNP/SWCNT photodetector exhibits an excellent photoelectrical performance with a responsivity of 2.16 × 105 A/W and a high detectivity of 1.82 × 1014 Jones, which is three orders of magnitude higher than that of the SWCNT photodetector under the same conditions. Importantly, the interfacial charge transfer between AuNPs and SWCNTs has been first investigated using Raman shift statistics at room temperature. Experimental results indicate that the interfacial charge transfer induced by AuNP doping can reduce the Fermi level of SWCNTs and effectively improve the generation and transport of photogenerated carriers, thereby enhancing the photoelectric performance of SWCNT-based photodetectors. We believe that our results not only demonstrate a facile route to improve the performance of SWCNT-based photodetectors but also provide a novel methodology to characterize the interfacial charge transfer between dopants and SWCNTs.

16.
Front Cardiovasc Med ; 9: 991161, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36158818

RESUMEN

Objective: The study aimed to assess the correlation and agreement between resting full-cycle ratio (RFR) and fractional flow reserve (FFR), and evaluate the guiding value of a hybrid RFR-FFR strategy for percutaneous coronary intervention (PCI) in a Chinese real-world cohort with non-ST elevation acute coronary syndrome (NSTE-ACS). Materials and methods: A total of 109 patients with NSTE-ACS (149 diseased vessels), who underwent an invasive physiological assessment in Cangzhou Central Hospital, Hebei Medical University, were prospectively enrolled from September 2021 to May 2022. FFR ≤ 0.80 was used as the gold standard for coronary artery functional ischemia. We utilized the Pearson correlation and Bland-Altman analysis to assess the correlation and agreement between RFR and FFR. The diagnostic value of RFR predicting FFR ≤ 0.80 was evaluated in accordance with the receiver operating characteristic (ROC) curve. The hybrid RFR-FFR strategy, which was established according to determining the "gray zone" of RFR (FFR was further assessed using vasodilators only for diseased vessels in the "gray zone"), needed to afford over 95% global agreement with the FFR-only strategy. Results: Resting full-cycle ratio was significantly linearly linked with FFR (R 2 = 0.636, P < 0.001). The accuracy, specificity, and sensitivity for RFR ≤ 0.89 predicting FFR ≤ 0.80 were 81.2, 70.8, and 86.1%, respectively. The area under the ROC curve for RFR predicting FFR ≤ 0.80 was 0.881 (P < 0.001), and the cutoff value was 0.90. The "gray zone" of RFR was 0.85-0.93. The positive and negative predictive values of the hybrid RFR-FFR strategy were 0.95 and 0.93, respectively. The hybrid RFR-FFR strategy exhibited an agreement of 96.0% with FFR and obviated the need for a vasodilator by 60.4%. Conclusion: Resting full-cycle ratio and FFR have high correlation and consistency. The hybrid RFR-FFR strategy highlights considerably enhanced agreement with the FFR-only strategy, whilst making the requirement of vasodilator administration less than a half.

17.
Perception ; 51(7): 505-513, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35581900

RESUMEN

Existent studies have demonstrated that being physically attractive leads to preferences and rewards in various scenarios involving performance evaluation. In this study, we explored whether a photographer's physical attractiveness could affect others' assessment of a photograph's aesthetic value. Participants (N=54) accomplished an online task to pair portraits and non-portrait photographs, followed by completing two questionnaires on cognitive reflection and empathy. Analytical results revealed that an attractive photographer was more likely to be associated with a highly aesthetic photograph, and this bias was moderated by the participant's level of cognitive reflection and empathy. Meanwhile, it could be reduced by the participant's professional experience.


Asunto(s)
Empatía , Fotograbar , Sesgo , Estética , Humanos
18.
Conserv Biol ; 2022 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-35435284

RESUMEN

Forests are essential common-pool resources. Understanding children's and adolescents' motivations for conservation is critical to improving conservation education. In 2 experiments, we investigated 1086 school-aged children and adolescents (6-16 years old) from China, the Democratic Republic of Congo, and the United States. testING participants in groups, we assessed their motivation for conservation based on collective-risk common-pool goods games in which they are threatened with losing their endowment unless the group donation exceeds a threshold needed to maintain the forest.eExtrinsic motivations, rather than intrinsic , tended to lead to successful cooperation to maintain a forest. Certainty of losing individual payoffs significantly boosted successful cooperative conservation efforts across cultures (success rates were 90.63 % and 74.19% in the 2 risk-extrinsic conditions and 43.75% in the control condition). In U.S. participants, 2 extrinsic incentives, priming discussions of the value of forests and delay of payoffs as punishment , also increased success of cooperative conservation (success rates were 97.22% and 76.92% in the 2 extrinsic-incentive conditions and 29.19% and 30.77% in the 2 control conditions). Conservation simulations, like those we used, may allow educators to encourage forest protection by leading groups to experience successful cooperation and the extrinsic incentives needed to motivate forest conservation. This article is protected by copyright. All rights reserved.

19.
ACS Sens ; 7(3): 816-826, 2022 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-35188381

RESUMEN

Practical application of wearable gas-sensing devices has been greatly inhibited by the poorly sensitive and specific recognition of target gases. Rapid charge transfer caused by rich sensory neurons in the biological olfactory system has inspired the construction of a highly sensitive sensor network with abundant defect sites for adsorption. Herein, for the first time, we demonstrate an in situ formed neuron-mimic gas sensor in a single gas-sensing channel, which is derived from lattice deviation of S atoms in Bi2S3 nanosheets induced by gold quantum dots. Due to the favorable gas adsorption and charge transfer properties arising from S vacancies, the fabricated sensor exhibits a significantly enhanced response value of 5.6-5 ppm NO2, ultrafast response/recovery performance (18 and 338 s), and excellent selectivity. Furthermore, real-time visual detection of target gases has been accomplished by integrating the flexible sensor into a wearable device.


Asunto(s)
Oro , Dispositivos Electrónicos Vestibles , Gases , Neuronas , Azufre
20.
Nanoscale ; 14(9): 3441-3451, 2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-35171186

RESUMEN

Recently, Ti3C2Tx MXenes have begun to receive attention in the field of gas sensors owing to their characteristics of high conductivity and abundant surface functional groups. However, Ti3C2Tx-based gas sensors still suffer from the drawbacks of low sensitivity and sluggish response/recovery speed towards target gases, limiting their development in further applications. In this work, Ti3C2Tx-ZnO nanosheet hybrids were fabricated through a simple sonication method. The Ti3C2Tx-ZnO nanosheet hybrids exhibited a short recovery time (10 s) under UV (ultraviolet) illumination, a short response time (22 s), a high sensitivity (367.63% to 20 ppm NO2) and selectivity. Furthermore, the Ti3C2Tx-ZnO sensor has prominent anti-humidity properties, as well as superior reproducibility in multiple tests. The abundant active sites in the Ti3C2Tx-ZnO nanosheet hybrids, including surface groups (-F, -OH, -O) of Ti3C2Tx and oxygen vacancies of ZnO, the formation of Schottky barriers between Ti3C2Tx and ZnO nanosheets and the rich photogenerated charge carriers of ZnO under UV illumination, together result in excellent gas-sensing performance. Density functional theory calculations have been further employed to explore the sensing performance of Ti3C2Tx and ZnO nanosheets, showing strong interactions existing between the NO2 and ZnO nanosheets. The main adsorption sites for NO2 were present on the ZnO nanosheets, while the Ti3C2Tx played the role of the conductive path to accelerate the transformation of charge carriers. Our work can provide an effective way for improving the gas-sensing performances of Ti3C2Tx-based gas sensors.

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