Yating Zhang

Electrochemical and Capacitive Properties of Carbon Dots/Reduced Graphene Oxide Supercapacitors

There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors was fabricated by anchoring carbon dots (CDs) on reduced graphene oxide (rGO). The capacitive properties of electrodes in aqueous electrolytes were systematically studied by galvanostatic charge-discharge measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. The capacitance of rGO was improved when an appropriate amount of CDs were added to the material. The CD/rGO electrode exhibited a good reversibility, excellent rate capability, fast charge transfer, and high specific capacitance in 1 M H2SO4. Its capacitance was as high as 211.9 F/g at a current density of 0.5 A/g. This capacitance was 74.3% higher than that of a pristine rGO electrode (121.6 F/g), and the capacitance of the CD/rGO electrode retained 92.8% of its original value after 1000 cycles at a CDs-to-rGO ratio of 5:1.

Preparation of graphene from Taixi anthracite and its photocatalyst performance for CO2 conversion

As a two-dimensional, single-layer sheet material, graphene attracts considerable attention and research interest because of its exceptional properties. In this work, coal-based graphene was synthesized with anthracite as a raw material by catalytic graphitization, chemical oxidation, and dielectric barrier discharge plasma. Coal-based graphene decorated with highly dispersed Pt nanoparticles on its surface (Pt/coal-based graphene) was successfully fabricated by the H2 dielectric barrier discharge plasma–assisted deoxygenation of a homogeneous dispersion of graphene oxide and chloroplatinic acid under ultrasonic conditions. Coal-based graphene and Pt/coal-based graphene were then used as catalysts in a CO2 reduction process. The graphitization degree of coal-based carbon remarkably affected the preparation of coal-based graphene. Pt/coal-based graphene exhibited good catalytic properties in the CO2 photocatalytic reduction process.