Zeolitic Imidazolate Framework Coated ZnO Nanorods as Molecular Sieving to Improve Selectivity of Formaldehyde Gas Sensor

Zinc oxide (ZnO) and zeolitic imidazolate framework-8 (ZIF–8) core–shell heterostructures were obtained by using the self-template strategy where ZnO nanorods not only act as the template, but also provide Zn²⁺ ions for the formation of ZIF–8 shell. The ZIF–8 shell was uniformly deposited to form ZnO@ZIF–8 nanorods with core–shell heterostructures at 70 °C for 24 h as the optimum reaction time by the hydrothermal synthesis. Transmission electron microscopy (TEM) images revealed that the ZnO@ZIF–8 heterostructures are composed of ZnO as core and ZIF–8 as shell. Nitrogen (N₂) sorption isotherms demonstrated that the as-prepared ZnO@ZIF–8 nanorods are a typical microporous material. Additionally, the ZnO@ZIF–8 nanorods sensor exhibited distinct gas response for reducing gases with different molecule sizes. The selectivity of the ZnO@ZIF–8 nanorods sensor was obviously improved for the detection of formaldehyde owing to the limitation effect of the aperture of ZIF–8 shell. This study demonstrated that semiconductor@MOF core–shell heterostructures may be a novel way to enhance the selectivity of the gas sensing materials

DataSheet1_Construction and Property Investigation of Serial Pillar[5]arene-Based [1]Rotaxanes.docx

Although the construction and application of pillar[5]arene-based [1]rotaxanes have been extensively studied, the types of stoppers for them are limited. In this work, we designed and prepared three series of pillar[5]arene-based [1]rotaxanes (P5[1]Rs) with pentanedione derivatives, azobenzene derivatives, and salicylaldehyde derivatives as the stoppers, respectively. The obtained P5[1]Rs were fully characterized by NMR (1H, 13C, and 2D), mass spectra, and single-crystal X-ray analysis. We found that the synergic C–H···π, C–H···O interactions and N–H···O, O–H···N hydrogen bonding are the key to the stability of [1]rotaxanes. This work not only enriched the diversity of pillar[n]arene family but also gave a big boost to the pillar[n]arene-based mechanically interlocked molecules</p

DataSheet4_Construction and Property Investigation of Serial Pillar[5]arene-Based [1]Rotaxanes.zip

Although the construction and application of pillar[5]arene-based [1]rotaxanes have been extensively studied, the types of stoppers for them are limited. In this work, we designed and prepared three series of pillar[5]arene-based [1]rotaxanes (P5[1]Rs) with pentanedione derivatives, azobenzene derivatives, and salicylaldehyde derivatives as the stoppers, respectively. The obtained P5[1]Rs were fully characterized by NMR (1H, 13C, and 2D), mass spectra, and single-crystal X-ray analysis. We found that the synergic C–H···π, C–H···O interactions and N–H···O, O–H···N hydrogen bonding are the key to the stability of [1]rotaxanes. This work not only enriched the diversity of pillar[n]arene family but also gave a big boost to the pillar[n]arene-based mechanically interlocked molecules</p

DataSheet3_Construction and Property Investigation of Serial Pillar[5]arene-Based [1]Rotaxanes.zip

Although the construction and application of pillar[5]arene-based [1]rotaxanes have been extensively studied, the types of stoppers for them are limited. In this work, we designed and prepared three series of pillar[5]arene-based [1]rotaxanes (P5[1]Rs) with pentanedione derivatives, azobenzene derivatives, and salicylaldehyde derivatives as the stoppers, respectively. The obtained P5[1]Rs were fully characterized by NMR (1H, 13C, and 2D), mass spectra, and single-crystal X-ray analysis. We found that the synergic C–H···π, C–H···O interactions and N–H···O, O–H···N hydrogen bonding are the key to the stability of [1]rotaxanes. This work not only enriched the diversity of pillar[n]arene family but also gave a big boost to the pillar[n]arene-based mechanically interlocked molecules</p

DataSheet2_Construction and Property Investigation of Serial Pillar[5]arene-Based [1]Rotaxanes.zip

Although the construction and application of pillar[5]arene-based [1]rotaxanes have been extensively studied, the types of stoppers for them are limited. In this work, we designed and prepared three series of pillar[5]arene-based [1]rotaxanes (P5[1]Rs) with pentanedione derivatives, azobenzene derivatives, and salicylaldehyde derivatives as the stoppers, respectively. The obtained P5[1]Rs were fully characterized by NMR (1H, 13C, and 2D), mass spectra, and single-crystal X-ray analysis. We found that the synergic C–H···π, C–H···O interactions and N–H···O, O–H···N hydrogen bonding are the key to the stability of [1]rotaxanes. This work not only enriched the diversity of pillar[n]arene family but also gave a big boost to the pillar[n]arene-based mechanically interlocked molecules</p

Battery-Sensor Hybrid: A New Gas Sensing Paradigm with Complete Energy Self-Sufficiency

Fully autonomous operation has long been an ultimate goal in environmental sensing. Although self-powered gas sensors based on energy harvesting have been widely reported to provide power for autonomous operation, these sensors rely on external sources of harvestable energy, thus are not completely self-sufficient. Herein, a battery-sensor hybrid device that can simultaneously function as both a power source and a gas sensor is presented. The battery-sensor consists of a cathode that reduces NO2 to NO2– via a catalyst with Fe–Nx species distributed on highly graphitic porous nitrogen-doped carbon. On the basis of the efficient and selective electrocatalytic activity of the catalyst, the battery-sensor is capable of sensing NO2 and does so without any external power, overcoming the long-standing grand challenge to achieve complete energy self-sufficiency. Furthermore, through controlling the working current the sensing range can be significantly expanded and electronically tuned, which is not only unprecedented for gas sensors but also of remarkable commercial practicality. The proposed battery-sensor hybrid architecture represents a new paradigm toward sensors with complete energy self-sufficiency

Battery-Sensor Hybrid: A New Gas Sensing Paradigm with Complete Energy Self-Sufficiency

Fully autonomous operation has long been an ultimate goal in environmental sensing. Although self-powered gas sensors based on energy harvesting have been widely reported to provide power for autonomous operation, these sensors rely on external sources of harvestable energy, thus are not completely self-sufficient. Herein, a battery-sensor hybrid device that can simultaneously function as both a power source and a gas sensor is presented. The battery-sensor consists of a cathode that reduces NO2 to NO2– via a catalyst with Fe–Nx species distributed on highly graphitic porous nitrogen-doped carbon. On the basis of the efficient and selective electrocatalytic activity of the catalyst, the battery-sensor is capable of sensing NO2 and does so without any external power, overcoming the long-standing grand challenge to achieve complete energy self-sufficiency. Furthermore, through controlling the working current the sensing range can be significantly expanded and electronically tuned, which is not only unprecedented for gas sensors but also of remarkable commercial practicality. The proposed battery-sensor hybrid architecture represents a new paradigm toward sensors with complete energy self-sufficiency

Flexible Waterproof Rechargeable Hybrid Zinc Batteries Initiated by Multifunctional Oxygen Vacancies-Rich Cobalt Oxide

Although both are based on Zn, Zn–air batteries and Zn–ion batteries are good at energy density and power density, respectively. Here, we adopted Ar–plasma to engrave a cobalt oxide with abundant oxygen vacancies (denoted as Co3O4–x). The introduction of oxygen vacancies to cobalt oxide not only promotes its reversible Co–O ↔ Co–O–OH redox reaction but also leads to good oxygen reduction reaction and oxygen evolution (ORR/OER) performance (a half-wave potential of 0.84 V, four-electron transfer process for ORR, and 330 mV overpotential, 58 mV·dec–1 Tafel slope for OER). We then constructed a battery system based on both Zn–Co3O4–x and Zn–air electrochemical reactions. The hybrid battery reveals both a high-power density of 3200 W·kg–1 and high-energy density of 1060 Wh·kg–1. Furthermore, the developed flexible solid-state hybrid batterydemonstrates good waterproof and washable ability (99.2% capacity retention of after 20 h water soaking test and 93.2% capacity retention after 1 h washing test). Interestingly, the fabricated flexible battery can work under water, and after the power is exhausted, the battery can automatically recover electricity output as long as it is exposed to air. The developed device is suitable for wearable applications considering its electrochemical performances, great environmental adaptation, and “air recoverability”. In addition, this study underscores the approach to develop hybrid energy-storage technologies through modification of electrode materials

Regulating Crystal Orientation in VO₂ for Aqueous Zinc Batteries with Enhanced Pseudocapacitance

Although aqueous zinc batteries have attracted extensive interest, they are limited by relatively low rate capabilities and poor cyclic stability of cathodes. The crystal orientation of the cathode is one important factor influencing electrochemical properties. However, it has rarely been investigated. Herein, VO2 cathodes with different crystal orientations are developed via tuning the number of hydroxyl groups in polyol, such as using glycerol, erythritol, xylitol, or mannitol. The polyols serve as a reductant as well as a structure-directing agent through a hydrothermal reaction. Xylitol-derived VO2 shows a (110)-orientated crystalline structure and ultrathin nanosheet morphology. Such features greatly enhance the pseudocapacitance to 76.1% at a scan rate of 1.0 mV s–1, which is significantly larger than that (61.6%) of the (001)-oriented VO2 derived from glycerol. The corresponding aqueous zinc batteries exhibit a high energy storage performance with a reversible specific capacity of 317 mAh g–1 at 0.5 A g–1, rate ability of 220 mAh g–1 at 10 A g–1, and capacity retention of 81.0% at 10 A g–1 over 2000 cycles. This work demonstrates a facile method for tailoring VO2 crystal orientations, offers an understanding of the Zn2+ storage mechanism upon different VO2 facets, and provides a novel method to develop cathode materials toward advanced aqueous zinc batteries