Metal-free carbon electrocatalyts for the oxygen reduction reaction (ORR) are attractive for their high activity and economic advantages. However, the origin of the activity has never been clearly elucidated in a syst...Metal-free carbon electrocatalyts for the oxygen reduction reaction (ORR) are attractive for their high activity and economic advantages. However, the origin of the activity has never been clearly elucidated in a systematic manner. Halogen group elements are good candidates for elucidating the effect, although it has been a difficult task due to safety issues. In this report, we demonstrate the synthesis of Cl-, Br- and I-doped reduced graphene oxide through two solution phase syntheses. We have evaluated the effectiveness of doping and performed electrochemical measurements of the ORR activity on these halogenated graphene materials. Our results suggest that the high electroneg-ativity of the dopant is not the key factor for high ORR activity; both Br- and I-doped graphene promoted ORR more efficiently than Cl-doped graphene. Furthermore, an unexpected sulfur-doping in acidic conditions suggests that a high level of sulfide can degrade the ORR activity of the graphene material.展开更多
We report a “soft” graphene oxide-polymeric organosulfide nanocomposite with improved pseudocapacitive performance for high-potential(1–2.8 V vs. Li^0/Li~+), high-capacity(278 mAh/g) and stable(500 cycles) l...We report a “soft” graphene oxide-polymeric organosulfide nanocomposite with improved pseudocapacitive performance for high-potential(1–2.8 V vs. Li^0/Li~+), high-capacity(278 mAh/g) and stable(500 cycles) lithium storage.展开更多
基金financial support from The University of Queensland and the Australian Research Council Discovery Project (DP110100550)
文摘Metal-free carbon electrocatalyts for the oxygen reduction reaction (ORR) are attractive for their high activity and economic advantages. However, the origin of the activity has never been clearly elucidated in a systematic manner. Halogen group elements are good candidates for elucidating the effect, although it has been a difficult task due to safety issues. In this report, we demonstrate the synthesis of Cl-, Br- and I-doped reduced graphene oxide through two solution phase syntheses. We have evaluated the effectiveness of doping and performed electrochemical measurements of the ORR activity on these halogenated graphene materials. Our results suggest that the high electroneg-ativity of the dopant is not the key factor for high ORR activity; both Br- and I-doped graphene promoted ORR more efficiently than Cl-doped graphene. Furthermore, an unexpected sulfur-doping in acidic conditions suggests that a high level of sulfide can degrade the ORR activity of the graphene material.
基金financial support from the ARC Discovery Project (No. DP160103244)the Baosteel Australia Joint Research and Development Centre (No. BA110016)
文摘We report a “soft” graphene oxide-polymeric organosulfide nanocomposite with improved pseudocapacitive performance for high-potential(1–2.8 V vs. Li^0/Li~+), high-capacity(278 mAh/g) and stable(500 cycles) lithium storage.