B-Doped g-C₃N₄ Quantum Dots-Modified Ni(OH)₂ Nanoflowers as an Efficient and Stable Electrode for Supercapacitors

Abstract

For increasing the specific capacitance of supercapacitors, boron-doped g-C 3 N 4 quantum dots (B-CNQDs) were synthesized by KOH cutting and further adsorbed on the surface of Ni(OH) 2 nanoflowers (B-CNQDx-Ni) by a mild impregnation method via electrostatic force. The B-CNQDx-Ni nanocomposites exhibit an increased surface area and reduced band gap energy compared with pure Ni(OH) 2 , which result in a larger contact area between the electrode and the electrolyte and enhanced chargetransfer kinetics. The best B-CNQDx-Ni sample has an excellent specific capacitance of 1700 F/g at 1.5 A/g, low impedance at the alkaline conduction of 7.421 Ω, and a high stability cycling performance of 82% capacity retention after 5000 cycles, suggesting that B-CNQDx-Ni is a type of suitable electrode material used in supercapacitors. KEYWORDS: Boron-doped g-C 3 N 4 quantum dots, KOH cutting, Ni(OH) 2 nanoflowers, supercapacitors, impregnation method

Nitrate Precursor Driven High Performance Ni/Co-MOF Nanosheets for Supercapacitors

“…The longer discharge time behavior of MN suggests that it has a larger specific capacitance, which can be evaluated by the calculation method reported before. 45 This result is consistent with the CV test result, where MN has a larger area. When the current density is 1 A/g, the specific capacitance calculated by the GCD test are 2860 F/g (MN) and 1350 F/g (MC), respectively.…”

“…Ni/Co-MOF­( MN ) and Ni/Co-MOF­( MC ) show symmetrical GCD curves, indicating that the electronic charge may be collected and released quickly at the same time, which proves that both MN and MC materials have good reversibility and high Coulombic efficiency. The longer discharge time behavior of MN suggests that it has a larger specific capacitance, which can be evaluated by the calculation method reported before . This result is consistent with the CV test result, where MN has a larger area.…”

“…The Ni-foam-supported composite materials were directly used as the working electrode, and cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) were used to evaluate the comprehensive performance of the MN and MC electrode materials. The specific capacitance ( C ), energy density ( E ), and power density ( P ) were calculated according to the literature and are detailed in the Supporting Information (SI).…”

Semiconducting Quantum Dots for Energy Conversion and Storage

“…[ 62 ] CN QDs possess a large amount of oxygenated groups and amine, which lead to the easy functionalization, [ 63 ] and thus CN QDs are promising materials for the application in energy conversion [ 64 ] and storage. [ 65 ]…”

Phosphorus–Oxygen-Codoped Graphitic Carbon Nitride for Enhanced Hydrogen Evolution and Photocatalytic Degradation under Visible Light Irradiation

“…Various strategies have been devoted to overcoming these drawbacks through tuning the photocatalytic and electronic properties of pristine CN, including heteroatom doping, , heterojunction, , and rational morphological or topological design. , As the electron transport between the nitrogen atom and the carbon atom in pristine CN is limited, doping metal heteroatoms − or nonmetal heteroatoms ,,− are known as an effective method to improve the photocatalytic performance of CN by distinctly adjusting its energy band structure, photoabsorption region, electronic conductivity, and charge transfer mobility. ,, Nonmetal atom doping has received extensive interest compared to metal atom doping because it could result in the formation of various conjugated triazine structures in the modified CN molecules. ,, As reported, , certain nonmetal atoms prefer the specific substitutional position of CN. In particular, phosphorus and bromine atoms prefer to substitute the nitrogen atoms, while oxygen and sulfur atoms are prone to displace the carbon atoms in pristine CN .…”