Carbon and graphene quantum dots in fuel cell application: An overview

Abstract

Summary Carbon quantum dots (CQD) and graphene quantum dots (GQDs) have been mentioned frequently. They have been selected in recent studies as they have unique and remarkable potential, especially in electrical, optical, and optoelectrical properties. CQD and GQDs have very high chemical and physical stability due to inherent inert carbon material, thus newly recognized as a kind of quantum dots material. Its environmentally friendly, non‐toxic, and naturally inactive nature is also a major attraction for scientists around the world. In this work, CQD and GQDs production methods are discussed in detail, including soft‐template method, hydrothermal method, microwave‐assisted hydrothermal (MAH) method, metal‐catalyzed method, liquid exfoliation method, electron beam lithography method, and others. Additive material has been introduced in CQD and GQDs to increase the ability and performance of CQD and GQDs such as nitrogen, sulfur, chlorine, fluorine, and potassium. In particular, the presence of additive material in CQD and GQDs shows an advantage in terms of energy level, which is very good at achieving specific requirements in properties such as optical, electrical, and optoelectrical. In addition, the existence of functional groups consisting of heteroatoms such as oxygen, nitrogen, sulfur, phosphorus, boron, and so on of zero‐dimensional carbon materials in providing an overabundance of the active electrochemical site for the reaction. The product of CQD and GQDs has various shapes and sizes influenced by several parameters such as synthesis temperature, growth time, source concentration, catalyst, and so on. The application of CQDs and GQDs composites in fuel cells has been clearly and scientifically stated as it has enhanced the performance of fuel cell technology.

Progress and challenges: Review for direct liquid fuel cell

“…The impede regarding the electrode performance includes: (i) methanol crossover, where the methanol and water penetrate through the membrane from anode side to the cathode side, which can reduce the cell performance; (ii) sluggish kinetic reaction in both anode and cathode side; MOR, and ORR; and (iii) catalyst poisoning happen in anode side due to the accumulation of the intermediate carbon species on the Pt electrocatalyst surface 240 . Such catalyst that can alleviate this issue and has a significant performance are non‐precious metal catalyst from the kind of transition metal, carbon material, nitrogen or boron‐doped carbon structure, and transition metal chalcogenides, and mixed composite of carbon‐doped nitrogen/boron with metal alloying 241,242 . However, most non‐platinum catalysts display lower activity, poor durability, and longevity than platinum catalysts, especially in the acidic medium due to the corrosion issue 241 .…”

Outstanding Graphene Quantum Dots from Carbon Source for Biomedical and Corrosion Inhibition Applications: A Review

“…It was successfully synthesized heteroatom-doped GQDs for fuel cell application through the hydrothermal method. The ability of GQDs as a unique material has been identified to enhance fuel cell activity as an ORR in catalytic and proton conductivity [209].…”

Internet of things energy system: Smart applications, technology advancement, and open issues

“…It is predicted that producing energy with free or low CO 2 emissions would be the major donor to restricting rise in global temperatures until 2 C. 88,89 When energy systems accelerate their step away from traditional fossilfuel power production, they become more dynamic internally and diversified. 90 Based on prime energy basis/supply (direct solar, wind, hydro, geothermal, ocean power, biomass, etc. ), energy carriers (heat, chemical features like hydrogen, water), energy storage (thermal, chemical, eg, hydrogen, ammonia), water storage (eg, electric batteries, supercapacitors), mechanical, gravitational and application are covered by abundantly articles.…”

“…It is predicted that producing energy with free or low CO 2 emissions would be the major donor to restricting rise in global temperatures until 2°C 88,89 . When energy systems accelerate their step away from traditional fossil‐fuel power production, they become more dynamic internally and diversified 90 . Based on prime energy basis/supply (direct solar, wind, hydro, geothermal, ocean power, biomass, etc.…”