Sulfur and nitrogen dual-doped graphdiyne as a highly efficient metal-free electrocatalyst for the Zn-air battery

Sulfur and nitrogen dual-doped graphdiyne(NSGD)has been found to be a promising catalyst for oxygen reduction reaction(ORR)through a combination of density functional theory(DFT)calculation and the application of oxygen evolution reaction(OER)experiments.The DFT analysis suggests that adsorption characteristics are significantly altered by resulting nitrogen and sulfur doping,which in turn affect the ORR activity.In particular,the NSGD-800 catalyst exhibits an increased ORR half-wave potential of 0.754 V,with enhanced stability due to the synergy effect of N and S.Meanwhile,thanks to the unique acetylene-rich structure of graphdiyne to anchor metal oxides with strong d-πinteractions,the activity and stability of com-RuO2 for OER were significantly enhanced by mixing with NSGD-800.The zinc-air battery(ZAB)with NSGD shows a much higher peak power density(87.3 mW cm^(−2))and longer charge-discharge cycle stability compared with the ZAB with Pt/C,making it an excellent candidate air electrode for ZAB and other energy storage and conversion devices.

Disordered carbon structures enhance capacitive storage

Electrochemical energy storage(EES)is a key technology in global research that focuses on the efficient storage and utilization of electrical energy generated from intermittent sources.The development of EES systems with high energy and power densities is essential for meeting the future energy demands of electrochemical capacitors,such as capacitors,which can store electrical energy obtained from intermittent sources and enable rapid energy transfer and transformation.Electrical double-layer capacitors(EDLCs)within porous carbon materials(Fig.1(a))are commercially popular because of their excellent conductivity and relatively low cost.Despite their advantages,the complex structure of nanoporous carbon materials hinders the optimization of supercapacitor performance.Although previous research has suggested that adjusting the pore size of nanoporous carbon materials can enhance their capacitive performance,conflicting reports and the lack of a definitive correlation between capacitance and pore size remain issues[1].Understanding the relationship between the structure of carbon materials and their capacitance is crucial for designing devices with high energy densities.