Biomass‐Derived Carbon Quantum Dots‐Induced Self‐Assembly of 3D Networks of Nickel‐Cobalt Double Hydroxide Nanorods as High‐Performance Electrode Materials for Supercapacitors

Abstract

The nickel-cobalt double hydroxide hybrid materials induced by biomass-derived carbon quantum dots (CQDs) have a threedimensional network structure of cross-linked nanorods. The results demonstrate that the functional groups on the CQDs derived from pomelo peel promoted the nucleation and confined the growth of nickel-cobalt double hydroxide. The assynthesized NiCo-LDH-CQDs-20 exhibits the high specific capacitance of 1814 F g À 1 at 1 A g À 1 . When the current density is increased to 15 A g À 1 , the specific capacitance value remains 75.5 % of the initial one, which indicates that NiCo-LDH-CQDs-20 has an extremely high-rate performance. Furthermore, the asymmetric supercapacitor NiCo-LDH-CQDs-20//AC provides a high energy density of 46.47 Wh kg À 1 in 2 M KOH solution with a power density of 800 W kg À 1 and maintains an initial specific capacitance of 82.7 % after 2000 cycles. Therefore, this study provides a promising approach for the development of anode active materials in supercapacitor energy storage devices.

Bio‐based nanomaterials for energy application: A review

“…77 In comparison to other approaches, the hydrothermal reaction is straightforward, inexpensive, and allows for control over the production of quantum dots. 78 Furthermore, this technique adheres to the sustainability theme because it does not involve toxic chemicals or harm both people and the environment. However, the drawback of hydrothermal is that the carbonization of the organic precursors takes a long time to occur.…”

“…Additionally, another asymmetric supercapacitor with a carbon anode and a composite of CQDs produced from pomelo peel and NiCo-LDH as a cathode, also presented good electrochemical performance, exhibiting energy and power densities of 46.47 Wh kg −1 and 800 W kg −1 , respectively. 78…”

“…For the hydrothermal synthesis of CQDs and GQDs, various organic precursors, mainly from biomass, are being studied 77 . In comparison to other approaches, the hydrothermal reaction is straightforward, inexpensive, and allows for control over the production of quantum dots 78 . Furthermore, this technique adheres to the sustainability theme because it does not involve toxic chemicals or harm both people and the environment.…”

Advances in Micro-/Mesopore Regulation Methods for Plant-Derived Carbon Materials

“…Carbon microspheres (0D) possess a unique hollow structure, which can provide a high specific surface area and a short diffusion distance. Using pomelo peel as a raw material, Zhuang et al [ 51 ] synthesized carbon quantum dots (CQD) by the hydrothermal method. Jagannathan et al [ 52 ] employed corn cob as a raw material to synthesize CQD and fabricated white light-emitting sheets ( Figure 2 ), which displayed uniform brightness and had good color reproducibility and high stability under various UV light.…”

Amino Acid Mediated Highly Ordered Carbon Dots as Phase Directing Agent for Synthesizing α-Ni(OH)2Decorated with Nitrogen Doped CD as an Electrode for an Efficient Symmetric Supercapacitor

“…Such functionalized carbon dots are known to favor nucleation and growth of metal oxides/hydroxides/sulfides, and sometimes they are useful for controlling morphology of the materials during their synthesis . Carbon dots are also known to play a role in structure directing agents and provide an excellent interface for the interactions between electrolyte ions and electrode material. , Incorporation of carbon dots on the surface of electroactive materials renders significant improvement of the efficiency of supercapacitor electrode material. − In addition, heteroatom (N, P, S, and B) doped CDs result in better charge storage performance . These surface functionalities and various dopants of CDs can act as redox-active centers, altering the electronic and optical properties of CDs by injecting more electrons into the carbon dot structure .…”