Hierarchically porous carbons with graphene incorporation for efficient supercapacitors

Biocatalyst and colorimetric biosensor of carcinoembryonic antigen constructed via chicken egg white-copper phosphate organic/inorganic hybrid nanoflowers

In this article, the dual-functional chicken egg white-copper phosphate organic-inorganic hybrid nanoflowers (Cu-NFs), combining the functions of signal amplification and biological recognition, were prepared through a simple one-pot method. The Cu-NFs exhibit excellent biocatalytic activity of peroxidase and polyphenol oxidase. Besides, a biotin-labeled secondary antibody encapsulated Cu-NFs-2 (Cu-NFs-2@Biotin-NHS-Ab₂) capture probe was prepared by using the interaction between avidin in the egg white and biotin. Based upon this superiority, the as-prepared Cu-NFs-2 were used in labeled avidin-biotin enzyme-linked immunosorbent assay (Cu-NFs-2 based-LAB-ELISA) to construct a sensitive colorimetric biosensor for the ultrasensitive detection of carcinoembryonic antigen (CEA). Under weak alkaline (pH = 7.5) conditions, the as-developed colorimetric sensor displayed a wide linear range of 0.05-40 ng/mL with a detection limit of 3.52 pg/mL. Furthermore, this colorimetric sensor has been successfully applied to the detection of CEA in human serum samples. Therefore, the as-developed colorimetric sensor has broad application prospects in the field of medical diagnosis and portable detection.

Enhanced faradic activity by construction of p-n junction within reduced graphene oxide@cobalt nickel sulfide@nickle cobalt layered double hydroxide composite electrode for charge storage in hybrid supercapacitor

The intrinsic faradic reactivity is the uppermost factor determining the charge storage capability of battery material, the construction of p-n junction composing of different faradic components is a rational tactics to enhance the faradic activity. Herein, a reduced graphene oxide@cobalt nickle sulfide@nickle cobalt layered double hydroxide composite (rGO@CoNi₂S₄@NiCo LDH) with p-n junction structure is designed by deposition of n-type nickle cobalt layered double hydroxide (NiCo LDH) around p-type reduced graphene oxide@cobalt nickle sulfide (rGO@CoNi₂S₄), the charge redistribution across the p-n junction enables enhanced faradic activities of both components and further the overall charge storage capacity of the resultant rGO@CoNi₂S₄@NiCo LDH battery electrode. As expected, the rGO@CoNi₂S₄@NiCo LDH electrode can deliver high specific capacity (C_s, 1310 ± 26 C g^-1 at 1 A g^-1) and good cycleability (77% C_s maintaining ratio undergoes 5000 charge-discharge cycles). Furthermore, the hybrid supercapacitor (HSC) based on the rGO@CoNi₂S₄@NiCo LDH p-n junction battery electrode exports high energy density (E_cell, 57.4 Wh kg^-1 at 323 W kg^-1) and good durability, showing the prospect of faradic p-n junction composite in battery typed energy storage.

Glucose-derived porous carbon as a highly efficient and low-cost counter electrode for quantum dot-sensitized solar cells

The power conversion efficiency of the QDSCs assembled with a CdS/CdSe sensitized TiO₂ photoanode and the C₉₀₀ CE is up to 5.61% under one sun illumination.

2D nanoporous Ni(OH)2 film as an electrode material for high-performance energy storage devices

A two-dimensional (2D) nanoporous Ni(OH)₂ film was successfully developed from triethanolamine (TEA) as the alkali source and soft template using a scalable hydrothermal technique. The nanostructured Ni(OH)₂ film was flexible and translucent, and could be directly compressed on a current collector. Owing to the uniform well-defined morphology and stable structure, the Ni(OH)₂ film binder-free electrode displayed a high specific capacity, exceptional rate capability, and admirable cycle life. The specific capacitance was 453.6 mA h g⁻¹ (1633 F g⁻¹) at 0.5 A g⁻¹. The assembled Ni(OH)₂//activated carbon (AC) asymmetric supercapacitor (ASC) device had an energy density of 58.7 W h kg⁻¹ at a power density of 400 W kg⁻¹. These prominent electrochemical properties of Ni(OH)₂ were attributed to the high electrical conductivity, high surface area, and unique porous architecture. Free tailoring, binder-free, and direct pressing were the most significant achievements of the Ni(OH)₂ film in the development of high-performance energy storage devices.

A two-dimensional (2D) nanoporous Ni(OH)₂ film was successfully developed from triethanolamine (TEA) as the alkali source and soft template using a scalable hydrothermal technique.

Nitrogen-doped graphene and graphene quantum dots: A review onsynthesis and applications in energy, sensors and environment

Doping of nitrogen is a promising strategy to modulate chemical, electronic, and structural functionalities of graphene (G)and graphene quantum dots (GQDs) for their outstanding properties in energy and environmental applications.This paper reviews various synthesis approaches of nitrogen-doped graphene (N-G) and nitrogen-doped graphene quantum dots (N-GQDs).;Thermal, ultrasonic, solvothermal, hydrothermal, and electron-beam methods have been applied to synthesize N-G and N-GQDs.These nitrogen-doped carbon materials are characterized to obtain their structural configurations in order to achieve better performance in their applications compared to only either graphene or graphene quantum dots.Both N-G and N-GQDs may be converted into functional materials by integrating with other compounds such as metal oxides/nitrides, polymers, and semiconductors.These functional materials demonstrate superior performance over N-G and N-GQDs materials.Examples of applications of N-G and N-GQDs include supercapacitors, batteries, sensors, fuel cells, solar cells, and photocatalyst.

A novel porous carbon material derived from the byproducts of bean curd stick manufacture for high-performance supercapacitor use

Preparation of heteroatom-functionalized porous carbon derived from byproducts of bean curd stick manufacture as an electrode material for high performance supercapacitors.