Speaker
Description
We perform spin-polarized calculation base on density functional theory in the frame of generalized gradient approximation to examine the quantum capacitance (CQ) and surface charge storage of graphene(G)-based supercapacitor electrodes modified with molybdenum, sulfur, nitrogen, and monovacancy. Several electrode models, including graphitic doping, monovacancy doping, and Mo adsorption on pristine and single-vacancy graphene structures were examined. The results demonstrate that vacancy defects and N/S/Mo doping enhances the CQ of graphene. Among all configurations, pyrrolic-S (d1S) showed the lowest CQ performance due to few states at the Fermi level. Electrodes with Mo adsorption exhibit the highest CQ, particularly when Mo is adsorbed at the top site of graphene. However, formation and adsorption energy calculations suggest Mo is more likely to adsorb at hollow sites. Optimally, Mo can be most effectively utilized by loading it onto vacancy or N/S-decorated vacancy sites. The significant contribution of Mo’s 4dz2 and 4s states to CQ, along with the charge-redistribution around the Mo complexes, may facilitate proton-coupled electron transfer to enhance pseudocapacitance
| Abstract Category | Materials Physics |
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