In this paper, Pt-Co_3O_4 nanocomposite was synthesized by a sol gel process combined with electrodeposition method. Its electrocatalytic activity towards methanol oxidation was investigated at room temperature using ...In this paper, Pt-Co_3O_4 nanocomposite was synthesized by a sol gel process combined with electrodeposition method. Its electrocatalytic activity towards methanol oxidation was investigated at room temperature using cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and current density time curve. It is found that the resultant Pt-Co_3O_4 catalysts with minute amount of Pt exhibite attractive electrocatalytic activity for methanol oxidation reaction(MOR) but with a high resistance CO poisoning due to the synergistic effects from Pt and Co_3O_4. Together with the low manufacturing cost of Co_3O_4, the reported nanostructured Pt-Co_3O_4 catalyst is expected to be a promising electrode material for direct methanol fuel cells(DMFC).展开更多
A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for hi...A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 mA.cm-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 21273192, 91023010, 61204009, 21303153)Innovation Scientists and Technicians Troop Construction Projects of Henan Province (Grant No. 104100510001)+1 种基金the Program for Science & Technology Innovation Talents in Universities of Henan Province (2008 HASTIT016)Henan Province Science and Technology Key Project (Grant No. 082102230036 and 122102210479)
文摘In this paper, Pt-Co_3O_4 nanocomposite was synthesized by a sol gel process combined with electrodeposition method. Its electrocatalytic activity towards methanol oxidation was investigated at room temperature using cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and current density time curve. It is found that the resultant Pt-Co_3O_4 catalysts with minute amount of Pt exhibite attractive electrocatalytic activity for methanol oxidation reaction(MOR) but with a high resistance CO poisoning due to the synergistic effects from Pt and Co_3O_4. Together with the low manufacturing cost of Co_3O_4, the reported nanostructured Pt-Co_3O_4 catalyst is expected to be a promising electrode material for direct methanol fuel cells(DMFC).
基金financially supported by the National Natural Science Foundation of China(Nos.51573107 and 21432005)the Youth Science and Technology Foundation of Sichuan Province(No.2013JQ0032)+2 种基金the Foundation of State Key Laboratory of Polymer Materials Engineering(sklpme2014-3-05)the Synergistic Innovation Joint Foundation of CAEPSCU(No.XTCX2014008)the Fundamental Research Funds for the Central Universities(Nos.2012SCU04B01 and YJ2011025)
文摘A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 mA.cm-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.
