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Organic electrochemical transistors (OECTs) provide the opportunity to fabricate flexible biosensors with high sensitivity. However, there are currently very few methods to improve the selectivity of OECT sensors. In this work, nitrogen/oxygen‐codoped carbon cloths (NOCCs) are prepared by the carbonization of polyaniline‐wrapped carbon cloths at 750 °C under different atmospheres. The resulting NOCC electrodes exhibit different electrochemical sensing behaviors toward ascorbic acid (AA) and dopamine (DA), enabling the fabrication of OECT sensors with high sensitivity and selectivity that are comparable to the state‐of‐the‐art OECT sensors for AA and DA. The structural characterization and theoretical calculation reveal that the electrochemical sensing behaviors of the NOCC electrodes are closely related to their surface compositions, providing an unprecedented strategy for the design of flexible OECT sensors with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

By directly bonding the monolayer organic based electrodes together to assemble the book-like multilayer electrode, increased areal capacity and high flexibility can be achieved. The electrodes represent 5.88 mA h cm−2 at 0.7C and 5.24 mA h cm−2 at 0.2C areal capacity in lithium-ion and sodium-ion batteries, respectively. [ABSTRACT FROM AUTHOR]

All-solid-state potassium ion-selective electrodes (K+ ISEs) using ordered mesoporous carbon (OMC) sphere as the solid contact (SC) are fabricated in this work, which exhibit excellent K+-sensing capability including the stable Nernstian response in a wide linear range of 10−4.19–10−0.21 M, a low detection limit of 5.4 μM, short response time, and good stability. The excellent performances of the K+ ISEs are attributable to the OMC spheres with interconnected mesopore structure, uniform spherical morphology, high surface area, high conductivity, and high capacitance, which provide the highly efficient ion-to-electron transduction between the ion-selective membrane and conductive component in the electrodes. More importantly, the OMC sphere-based SC layer can be deposited in the flexible ISEs by solution processing, which thus enables the construction of ion-sensitive field-effect transistor-based handheld K+-sensing system with high sensitivity and reproducibility, demonstrating the potentials of the OMC spheres in practical ion detection devices. [ABSTRACT FROM AUTHOR]

Developing effective synthetic strategies as well as enriching functionalities for sp2‐carbon‐linked covalent organic frameworks (COFs) still remains a challenge. Now, taking advantage of a variant of Knoevenagel condensation, a new fully conjugated COF (g‐C34N6‐COF) linked by unsubstituted C=C bonds was synthesized. Integrating 3,5‐dicyano‐2,4,6‐trimethylpyridine and 1,3,5‐triazine units into the molecular framework leads to the enhanced π‐electron communication and electrochemical activity. This COF shows uniform nanofibrous morphology. By assembling it with carbon nanotubes, a flexible thin‐film electrode for a micro‐supercapacitor (MSC) can be easily obtained. The resultant COF‐based MSC shows an areal capacitance of up to 15.2 mF cm−2, a high energy density of up to 7.3 mWh cm−3, and remarkable rate capability. These values are among the highest for state‐of‐the‐art MSCs. Moreover, this device exhibits excellent flexibility and integration capability. [ABSTRACT FROM AUTHOR]

Developing effective synthetic strategies as well as enriching functionalities for sp2‐carbon‐linked covalent organic frameworks (COFs) still remains a challenge. Now, taking advantage of a variant of Knoevenagel condensation, a new fully conjugated COF (g‐C34N6‐COF) linked by unsubstituted C=C bonds was synthesized. Integrating 3,5‐dicyano‐2,4,6‐trimethylpyridine and 1,3,5‐triazine units into the molecular framework leads to the enhanced π‐electron communication and electrochemical activity. This COF shows uniform nanofibrous morphology. By assembling it with carbon nanotubes, a flexible thin‐film electrode for a micro‐supercapacitor (MSC) can be easily obtained. The resultant COF‐based MSC shows an areal capacitance of up to 15.2 mF cm−2, a high energy density of up to 7.3 mWh cm−3, and remarkable rate capability. These values are among the highest for state‐of‐the‐art MSCs. Moreover, this device exhibits excellent flexibility and integration capability. [ABSTRACT FROM AUTHOR]

A three-dimensional polymeric carbon nitride/graphene framework (CN/GF) was fabricated by the ionic self-assembly of graphene oxide and protonated polymeric carbon nitride nanosheets. As the cathode material in lithium-ion batteries, CN/GF showed an excellent reversible capacity of 184 mA h g−1 at 0.05 A g−1 for 150 cycles and maintained the capacity of 60 mA h g−1 at 5 A g−1. [ABSTRACT FROM AUTHOR]

In this work, a novel strategy to fabricate ternary MoS 2 /SiO 2 /graphene hybrids (MSGs) was developed by incorporating amorphous SiO 2 with MoS 2 and graphene nanosheets. Serving as anode material in lithium ion batteries, the inert silica component can effectively prevent the pulverization caused by the inner-plane volume expansion of MoS 2 . It turns out that MSGs with ∼40 wt% of SiO 2 and ∼42 wt% of MoS 2 manifest the capacity stabilized at 1060 mAh g −1 for more than 100 cycles at the current density of 0.1 A g −1 . Further, this MSG electrode maintains the specific capacity of 580 mAh g −1 at an ultrahigh current density of 8 Ag −1 , which outperforms those of the reported MoS 2 and MoS 2 /graphene hybrids. [ABSTRACT FROM AUTHOR]